Author: "(0000-0001-6200-6406) Rehwald, M." - Searchworks@Jio Institute Digital Library Search Results

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1. Absolute energy-dependent scintillating screen calibration for real-time detection of laser-accelerated proton bunches

Author: (0009-0004-0743-4087) Schilz, J. D., (0000-0001-8205-8422) Bodenstein, E., (0000-0002-9859-2408) Brack, F.-E., (0000-0003-0707-0856) Horst, F., (0000-0002-4626-0049) Irman, A., (0000-0002-0275-9892) Kroll, F., (0000-0003-4128-5498) Pawelke, J., (0000-0003-0931-1350) Prencipe, I., (0000-0001-6200-6406) Rehwald, M., (0000-0003-4962-2153) Reimold, M., (0000-0002-2769-4749) Schöbel, S., (0000-0003-0390-7671) Schramm, U., (0000-0003-3926-409X) Zeil, K., (0000-0002-9556-0662) Metzkes-Ng, J., (0009-0004-0743-4087) Schilz, J. D., (0000-0001-8205-8422) Bodenstein, E., (0000-0002-9859-2408) Brack, F.-E., (0000-0003-0707-0856) Horst, F., (0000-0002-4626-0049) Irman, A., (0000-0002-0275-9892) Kroll, F., (0000-0003-4128-5498) Pawelke, J., (0000-0003-0931-1350) Prencipe, I., (0000-0001-6200-6406) Rehwald, M., (0000-0003-4962-2153) Reimold, M., (0000-0002-2769-4749) Schöbel, S., (0000-0003-0390-7671) Schramm, U., (0000-0003-3926-409X) Zeil, K., and (0000-0002-9556-0662) Metzkes-Ng, J.
Abstract: Laser-plasma accelerators (LPAs) can deliver pico- to nanosecond long proton bunches, with ≥∼100 nC of charge dispersed over a broad energy spectrum. Increasing the repetition rates of today’s LPAs is a necessity for their practical application. This, however, creates a need for real-time proton bunch diagnostics. Scintillating screens are one detector solution, commonly applied in the field of electron LPAs for spatially resolved particle and radiation detection, yet their establishment for LPA proton detection is only slowly taking off. This is also due to the lack of available calibrations. In this paper, we present an absolute proton number calibration for the scintillating screen type DRZ High (Mitsubishi Chemical Corporation, Düsseldorf, Germany), one of the most sensitive screens according to calibrations for relativistic electrons and x-rays. For proton irradiation of the DRZ High screen, we find an increase in light yield of >60% compared to reference calibration data for relativistic electrons. The presented absolute light yield calibration shows an uncertainty of the proton number of 10% and can seamlessly be applied at other LPA facilities. Moreover, we investigate the scintillating screen light yield dependence on proton energy, since many types of scintillators (e.g., plastic, liquid, inorganic) show a reduced light yield for increased local energy deposition densities, an effect termed ionization quenching. The ionization quenching can reduce the light yield for low-energy protons by up to ∼20%. This work provides all necessary data for absolute spectral measurements of LPA protons with DRZ High scintillating screens, e.g., when these are used as detectors in the commonly available Thomson parabola spectrometers.
Published: 2024

2. Data publication: Absolute energy-dependent scintillating screen calibration for real-time detection of laser-accelerated proton bunches

Author: (0009-0004-0743-4087) Schilz, J. D., (0000-0001-8205-8422) Bodenstein, E., (0000-0002-9859-2408) Brack, F.-E., (0000-0003-0707-0856) Horst, F., (0000-0002-4626-0049) Irman, A., (0000-0002-0275-9892) Kroll, F., (0000-0003-4128-5498) Pawelke, J., (0000-0003-0931-1350) Prencipe, I., (0000-0001-6200-6406) Rehwald, M., (0000-0003-4962-2153) Reimold, M., (0000-0002-2769-4749) Schöbel, S., (0000-0003-0390-7671) Schramm, U., (0000-0003-3926-409X) Zeil, K., (0000-0002-9556-0662) Metzkes-Ng, J., (0009-0004-0743-4087) Schilz, J. D., (0000-0001-8205-8422) Bodenstein, E., (0000-0002-9859-2408) Brack, F.-E., (0000-0003-0707-0856) Horst, F., (0000-0002-4626-0049) Irman, A., (0000-0002-0275-9892) Kroll, F., (0000-0003-4128-5498) Pawelke, J., (0000-0003-0931-1350) Prencipe, I., (0000-0001-6200-6406) Rehwald, M., (0000-0003-4962-2153) Reimold, M., (0000-0002-2769-4749) Schöbel, S., (0000-0003-0390-7671) Schramm, U., (0000-0003-3926-409X) Zeil, K., and (0000-0002-9556-0662) Metzkes-Ng, J.
Abstract: All necessary Data to recreate the published plots and images in the publication: "Absolute energy-dependent scintillating screen calibration for real-time detection of laser-accelerated proton bunches". Included are the raw scintillating screen images, the plotting data and Python Scripts used for calculations and plotting.
Published: 2024

3. Laser-driven high-energy proton beams from cascaded acceleration regimes

Author: (0000-0002-3727-7017) Ziegler, T., Göthel, I., (0000-0002-6928-2048) Assenbaum, S., (0000-0003-1739-0159) Bernert, C., (0000-0002-9859-2408) Brack, F.-E., (0000-0002-5845-000X) Cowan, T., (0000-0003-0420-3940) Dover, N. P., (0000-0002-6914-4083) Gaus, L., (0000-0003-4861-5584) Kluge, T., (0000-0002-0638-6990) Kraft, S., (0000-0002-0275-9892) Kroll, F., (0000-0002-9556-0662) Metzkes-Ng, J., (0000-0001-8143-0827) Nishiuchi, M., (0000-0003-0931-1350) Prencipe, I., (0000-0002-4738-6436) Püschel, T., (0000-0001-6200-6406) Rehwald, M., (0000-0003-4962-2153) Reimold, M., (0000-0003-4400-1315) Schlenvoigt, H.-P., (0000-0001-7332-7395) Umlandt, M. E. P., (0000-0002-2828-5373) Vescovi Pinochet, M. A., (0000-0003-0390-7671) Schramm, U., (0000-0003-3926-409X) Zeil, K., (0000-0002-3727-7017) Ziegler, T., Göthel, I., (0000-0002-6928-2048) Assenbaum, S., (0000-0003-1739-0159) Bernert, C., (0000-0002-9859-2408) Brack, F.-E., (0000-0002-5845-000X) Cowan, T., (0000-0003-0420-3940) Dover, N. P., (0000-0002-6914-4083) Gaus, L., (0000-0003-4861-5584) Kluge, T., (0000-0002-0638-6990) Kraft, S., (0000-0002-0275-9892) Kroll, F., (0000-0002-9556-0662) Metzkes-Ng, J., (0000-0001-8143-0827) Nishiuchi, M., (0000-0003-0931-1350) Prencipe, I., (0000-0002-4738-6436) Püschel, T., (0000-0001-6200-6406) Rehwald, M., (0000-0003-4962-2153) Reimold, M., (0000-0003-4400-1315) Schlenvoigt, H.-P., (0000-0001-7332-7395) Umlandt, M. E. P., (0000-0002-2828-5373) Vescovi Pinochet, M. A., (0000-0003-0390-7671) Schramm, U., and (0000-0003-3926-409X) Zeil, K.
Abstract: Laser-driven ion accelerators can deliver high-energy, high-peak current beams and are thus attracting attention as a compact alternative to conventional accelerators. However, achieving sufficiently high energy levels suitable for applications such as radiation therapy remains a challenge for laser-driven ion accelerators. Here we generate proton beams with a spectrally separated high-energy component of up to 150 MeV by irradiating solid-density plastic foil targets with ultrashort laser pulses from a repetitive petawatt laser. The preceding laser light heats the target, leading to the onset of relativistically induced transparency upon main pulse arrival. The laser peak then penetrates the initially opaque target and triggers proton acceleration through a cascade of different mechanisms, as revealed by three-dimensional particle-in-cell simulations. The transparency of the target can be used to identify the high-performance domain, making it a suitable feedback parameter for automated laser and target optimization to enhance stability of plasma accelerators in the future.
Published: 2024

4. Source data: Enhanced ion acceleration from transparency-driven foils demonstrated at two ultraintense laser facilities

Author: (0000-0003-0420-3940) Dover, N. P., (0000-0002-3727-7017) Ziegler, T., (0000-0002-6928-2048) Assenbaum, S., (0000-0003-1739-0159) Bernert, C., (0000-0002-1919-8585) Bock, S., (0000-0002-9859-2408) Brack, F.-E., (0000-0002-5845-000X) Cowan, T., Ditter, E. J., Garten, M., Gaus, L., Göthel, I., Hicks, G. S., Kiriyama, H., (0000-0003-4861-5584) Kluge, T., (0000-0002-7231-0206) Koga, J. K., Kon, A., Kondo, K., (0000-0002-0638-6990) Kraft, S., (0000-0002-0275-9892) Kroll, F., Lowe, H. F., (0000-0002-9556-0662) Metzkes-Ng, J., Miyatake, T., Najmudin, Z., (0000-0002-4738-6436) Püschel, T., (0000-0001-6200-6406) Rehwald, M., Reimold, M., Sakaki, H., (0000-0003-4400-1315) Schlenvoigt, H.-P., Shiokawa, K., (0000-0001-7332-7395) Umlandt, M. E. P., (0000-0003-0390-7671) Schramm, U., (0000-0003-3926-409X) Zeil, K., (0000-0001-8143-0827) Nishiuchi, M., (0000-0003-0420-3940) Dover, N. P., (0000-0002-3727-7017) Ziegler, T., (0000-0002-6928-2048) Assenbaum, S., (0000-0003-1739-0159) Bernert, C., (0000-0002-1919-8585) Bock, S., (0000-0002-9859-2408) Brack, F.-E., (0000-0002-5845-000X) Cowan, T., Ditter, E. J., Garten, M., Gaus, L., Göthel, I., Hicks, G. S., Kiriyama, H., (0000-0003-4861-5584) Kluge, T., (0000-0002-7231-0206) Koga, J. K., Kon, A., Kondo, K., (0000-0002-0638-6990) Kraft, S., (0000-0002-0275-9892) Kroll, F., Lowe, H. F., (0000-0002-9556-0662) Metzkes-Ng, J., Miyatake, T., Najmudin, Z., (0000-0002-4738-6436) Püschel, T., (0000-0001-6200-6406) Rehwald, M., Reimold, M., Sakaki, H., (0000-0003-4400-1315) Schlenvoigt, H.-P., Shiokawa, K., (0000-0001-7332-7395) Umlandt, M. E. P., (0000-0003-0390-7671) Schramm, U., (0000-0003-3926-409X) Zeil, K., and (0000-0001-8143-0827) Nishiuchi, M.
Abstract: This dataset contains all source data used to generate figures and all other findings of the publication: " Enhanced ion acceleration from transparency-driven foils demonstrated at two ultraintense laser facilities".
Published: 2024

5. Source Data: Laser-driven high-energy proton beams from cascaded acceleration regimes

Author: (0000-0002-3727-7017) Ziegler, T., Göthel, I., (0000-0002-6928-2048) Assenbaum, S., (0000-0003-1739-0159) Bernert, C., (0000-0002-9859-2408) Brack, F.-E., (0000-0002-5845-000X) Cowan, T., (0000-0003-0420-3940) Dover, N. P., (0000-0002-6914-4083) Gaus, L., (0000-0003-4861-5584) Kluge, T., (0000-0002-0638-6990) Kraft, S., (0000-0002-0275-9892) Kroll, F., (0000-0002-9556-0662) Metzkes-Ng, J., (0000-0001-8143-0827) Nishiuchi, M., (0000-0003-0931-1350) Prencipe, I., (0000-0002-4738-6436) Püschel, T., (0000-0001-6200-6406) Rehwald, M., (0000-0003-4962-2153) Reimold, M., (0000-0003-4400-1315) Schlenvoigt, H.-P., (0000-0001-7332-7395) Umlandt, M. E. P., (0000-0002-2828-5373) Vescovi Pinochet, M. A., (0000-0003-0390-7671) Schramm, U., (0000-0003-3926-409X) Zeil, K., (0000-0002-3727-7017) Ziegler, T., Göthel, I., (0000-0002-6928-2048) Assenbaum, S., (0000-0003-1739-0159) Bernert, C., (0000-0002-9859-2408) Brack, F.-E., (0000-0002-5845-000X) Cowan, T., (0000-0003-0420-3940) Dover, N. P., (0000-0002-6914-4083) Gaus, L., (0000-0003-4861-5584) Kluge, T., (0000-0002-0638-6990) Kraft, S., (0000-0002-0275-9892) Kroll, F., (0000-0002-9556-0662) Metzkes-Ng, J., (0000-0001-8143-0827) Nishiuchi, M., (0000-0003-0931-1350) Prencipe, I., (0000-0002-4738-6436) Püschel, T., (0000-0001-6200-6406) Rehwald, M., (0000-0003-4962-2153) Reimold, M., (0000-0003-4400-1315) Schlenvoigt, H.-P., (0000-0001-7332-7395) Umlandt, M. E. P., (0000-0002-2828-5373) Vescovi Pinochet, M. A., (0000-0003-0390-7671) Schramm, U., and (0000-0003-3926-409X) Zeil, K.
Abstract: This dataset contains all source data used to generate figures and all other findings of the publication: "Laser-driven high-energy proton beams from cascaded acceleration regimes".
Published: 2024

6. Laser Transmission in the Relativistically Induced Transparency Regime for High Performance Proton Acceleration at PW Laser Systems

Author: (0000-0001-7332-7395) Umlandt, M. E. P., (0000-0002-6928-2048) Assenbaum, S., (0000-0003-1739-0159) Bernert, C., (0000-0002-1919-8585) Bock, S., (0000-0002-9859-2408) Brack, F.-E., (0000-0002-5845-000X) Cowan, T., Ditter, E. J., Dover, N. P., (0000-0001-6994-2475) Garten, M., (0000-0002-6914-4083) Gaus, L., Göthel, I., Hicks, G. S., Kiriyama, H., (0000-0003-4861-5584) Kluge, T., (0000-0002-7231-0206) Koga, J. K., Kon, A., Kondo, K., (0000-0002-0638-6990) Kraft, S., (0000-0002-0275-9892) Kroll, F., Lowe, H. F., (0000-0002-9556-0662) Metzkes-Ng, J., Miyatake, T., Najmudin, Z., (0000-0001-8143-0827) Nishiuchi, M., (0000-0002-4738-6436) Püschel, T., (0000-0001-6200-6406) Rehwald, M., (0000-0003-4962-2153) Reimold, M., Sakaki, H., (0000-0003-4400-1315) Schlenvoigt, H.-P., Shiokawa, K., (0000-0003-3926-409X) Zeil, K., (0000-0002-3727-7017) Ziegler, T., (0000-0003-0390-7671) Schramm, U., (0000-0001-7332-7395) Umlandt, M. E. P., (0000-0002-6928-2048) Assenbaum, S., (0000-0003-1739-0159) Bernert, C., (0000-0002-1919-8585) Bock, S., (0000-0002-9859-2408) Brack, F.-E., (0000-0002-5845-000X) Cowan, T., Ditter, E. J., Dover, N. P., (0000-0001-6994-2475) Garten, M., (0000-0002-6914-4083) Gaus, L., Göthel, I., Hicks, G. S., Kiriyama, H., (0000-0003-4861-5584) Kluge, T., (0000-0002-7231-0206) Koga, J. K., Kon, A., Kondo, K., (0000-0002-0638-6990) Kraft, S., (0000-0002-0275-9892) Kroll, F., Lowe, H. F., (0000-0002-9556-0662) Metzkes-Ng, J., Miyatake, T., Najmudin, Z., (0000-0001-8143-0827) Nishiuchi, M., (0000-0002-4738-6436) Püschel, T., (0000-0001-6200-6406) Rehwald, M., (0000-0003-4962-2153) Reimold, M., Sakaki, H., (0000-0003-4400-1315) Schlenvoigt, H.-P., Shiokawa, K., (0000-0003-3926-409X) Zeil, K., (0000-0002-3727-7017) Ziegler, T., and (0000-0003-0390-7671) Schramm, U.
Abstract: Ion acceleration by laser-plasma sources promises many applications, but reaching the required beam quality parameters demands a high level of understanding and control over the interaction process. Several advanced schemes, including the Relativistically Induced Transparency (RIT) regime, have been proposed and investigated in search of a stable acceleration for proton energies beyond 100 MeV. In the RIT scheme, the absorption of the electromagnetic laser field by the target and the generated plasma is critical. In joint experiments at the DRACO PW (HZDR) and J-KAREN (KPSI) lasers, we use transmission diagnostics to study the onset of transparency and learn about the sensitivity of the laser input to improve the process’s robustness. Using ultra-short pulses on thin solid density foil targets, we observe high performance proton beams in an expanded foil case. Our analysis of the effects on the transmission and its correlation with the acceleration performance indicates changes in the plasma interaction process.
Published: 2023

7. Laser Transmission in the Relativistically Induced Transparency Regime for High Performance Proton Acceleration at PW Laser Systems

Author: (0000-0001-7332-7395) Umlandt, M. E. P., (0000-0002-6928-2048) Assenbaum, S., (0000-0003-1739-0159) Bernert, C., (0000-0002-1919-8585) Bock, S., (0000-0002-9859-2408) Brack, F.-E., (0000-0002-5845-000X) Cowan, T., Ditter, E. J., Dover, N. P., (0000-0001-6994-2475) Garten, M., (0000-0002-6914-4083) Gaus, L., Göthel, I., Hicks, G. S., Kiriyama, H., (0000-0003-4861-5584) Kluge, T., (0000-0002-7231-0206) Koga, J. K., Kon, A., Kondo, K., (0000-0002-0638-6990) Kraft, S., (0000-0002-0275-9892) Kroll, F., Lowe, H. F., (0000-0002-9556-0662) Metzkes-Ng, J., Miyatake, T., Najmudin, Z., (0000-0001-8143-0827) Nishiuchi, M., (0000-0002-4738-6436) Püschel, T., (0000-0001-6200-6406) Rehwald, M., (0000-0003-4962-2153) Reimold, M., Sakaki, H., (0000-0003-4400-1315) Schlenvoigt, H.-P., Shiokawa, K., (0000-0003-3926-409X) Zeil, K., (0000-0002-3727-7017) Ziegler, T., (0000-0003-0390-7671) Schramm, U., (0000-0001-7332-7395) Umlandt, M. E. P., (0000-0002-6928-2048) Assenbaum, S., (0000-0003-1739-0159) Bernert, C., (0000-0002-1919-8585) Bock, S., (0000-0002-9859-2408) Brack, F.-E., (0000-0002-5845-000X) Cowan, T., Ditter, E. J., Dover, N. P., (0000-0001-6994-2475) Garten, M., (0000-0002-6914-4083) Gaus, L., Göthel, I., Hicks, G. S., Kiriyama, H., (0000-0003-4861-5584) Kluge, T., (0000-0002-7231-0206) Koga, J. K., Kon, A., Kondo, K., (0000-0002-0638-6990) Kraft, S., (0000-0002-0275-9892) Kroll, F., Lowe, H. F., (0000-0002-9556-0662) Metzkes-Ng, J., Miyatake, T., Najmudin, Z., (0000-0001-8143-0827) Nishiuchi, M., (0000-0002-4738-6436) Püschel, T., (0000-0001-6200-6406) Rehwald, M., (0000-0003-4962-2153) Reimold, M., Sakaki, H., (0000-0003-4400-1315) Schlenvoigt, H.-P., Shiokawa, K., (0000-0003-3926-409X) Zeil, K., (0000-0002-3727-7017) Ziegler, T., and (0000-0003-0390-7671) Schramm, U.
Abstract: Ion acceleration by laser-plasma sources promises many applications, but reaching the required beam quality parameters demands a high level of understanding and control over the interaction process. Several advanced schemes, including the Relativistically Induced Transparency (RIT) regime, have been proposed and investigated in search of a stable acceleration for proton energies beyond 100 MeV. In the RIT scheme, the absorption of the electromagnetic laser field by the target and the generated plasma is critical. In joint experiments at the DRACO PW (HZDR) and J-KAREN (KPSI) lasers, we use transmission diagnostics to study the onset of transparency and learn about the sensitivity of the laser input to improve the process’s robustness. Using ultra-short pulses on thin solid density foil targets, we observe high performance proton beams in an expanded foil case. Our analysis of the effects on the transmission and its correlation with the acceleration performance indicates changes in the plasma interaction process.
Published: 2023

8. Optimizing PW Laser-Driven Proton Acceleration by Characterizing Laser Transmission of Relativistically Transparent Targets

Author: (0000-0001-7332-7395) Umlandt, M. E. P., (0000-0002-6928-2048) Assenbaum, S., (0000-0003-1739-0159) Bernert, C., (0000-0002-1919-8585) Bock, S., (0000-0002-9859-2408) Brack, F.-E., (0000-0002-5845-000X) Cowan, T., Ditter, E. J., Dover, N. P., (0000-0001-6994-2475) Garten, M., (0000-0002-6914-4083) Gaus, L., Göthel, I., Hicks, G. S., Kiriyama, H., (0000-0003-4861-5584) Kluge, T., (0000-0002-7231-0206) Koga, J. K., Kon, A., Kondo, K., (0000-0002-0638-6990) Kraft, S., (0000-0002-0275-9892) Kroll, F., Lowe, H. F., (0000-0002-9556-0662) Metzkes-Ng, J., Miyatake, T., Najmudin, Z., (0000-0001-8143-0827) Nishiuchi, M., (0000-0002-4738-6436) Püschel, T., (0000-0001-6200-6406) Rehwald, M., (0000-0003-4962-2153) Reimold, M., Sakaki, H., (0000-0003-4400-1315) Schlenvoigt, H.-P., Shiokawa, K., (0000-0003-3926-409X) Zeil, K., (0000-0002-3727-7017) Ziegler, T., (0000-0003-0390-7671) Schramm, U., (0000-0001-7332-7395) Umlandt, M. E. P., (0000-0002-6928-2048) Assenbaum, S., (0000-0003-1739-0159) Bernert, C., (0000-0002-1919-8585) Bock, S., (0000-0002-9859-2408) Brack, F.-E., (0000-0002-5845-000X) Cowan, T., Ditter, E. J., Dover, N. P., (0000-0001-6994-2475) Garten, M., (0000-0002-6914-4083) Gaus, L., Göthel, I., Hicks, G. S., Kiriyama, H., (0000-0003-4861-5584) Kluge, T., (0000-0002-7231-0206) Koga, J. K., Kon, A., Kondo, K., (0000-0002-0638-6990) Kraft, S., (0000-0002-0275-9892) Kroll, F., Lowe, H. F., (0000-0002-9556-0662) Metzkes-Ng, J., Miyatake, T., Najmudin, Z., (0000-0001-8143-0827) Nishiuchi, M., (0000-0002-4738-6436) Püschel, T., (0000-0001-6200-6406) Rehwald, M., (0000-0003-4962-2153) Reimold, M., Sakaki, H., (0000-0003-4400-1315) Schlenvoigt, H.-P., Shiokawa, K., (0000-0003-3926-409X) Zeil, K., (0000-0002-3727-7017) Ziegler, T., and (0000-0003-0390-7671) Schramm, U.
Abstract: Ion acceleration by compact laser-plasma sources has great potential for a range of applications, including those with medical relevance and fusion experiments. However, in order to achieve the necessary beam quality parameters for these applications, a thorough understanding and control over the laser-plasma interaction process is required. Therefore, we are exploring laser plasma acceleration around the promising regime of Relativistically Induced Transparency (RIT) through joint studies at DRACO PW (HZDR) and the J-KAREN-P laser system at KPSI. We have performed thickness scans to investigate the relation between proton acceleration performance and target transparency, revealing high-performance proton beams (> 60 MeV) in an expanded foil case, with an optimum at the onset of target transparency. [1] Subsequent experiments showed even higher proton energies. Clearly, the relationship between the transparency onset time and the acceleration performance is crucial for achieving optimal beam parameters, improving our understanding of the sensitivity of laser input parameters, and increasing the process’s robustness. Thus, we are using a combination of particle and laser diagnostics to investigate this correlation. In this contribution, we present a summary of our studies in which we use spectral interferometry with the unperturbed laser beam as a reference to evaluate the output of reflected and transmitted light diagnostics. Obtaining features like shown in Bagnoud et al. [2] and Williamson et al. [3], we additionally correlate these measures with the proton acceleration performance and show first results of spectral, spatial, and energy analysis of the effects on the laser transmission through the target. References [1] Dover, N. P. et al.: Enhanced ion acceleration from transparency-driven foils demonstrated at two ultraintense laser facilities. Light Sci. Appl. in press (2023). [2] Bagnoud, V. et al.: Studying the Dynamics of Relativistic Laser-Plasma Interactio
Published: 2023

9. Time-resolved optical shadowgraphy of solid hydrogen jets as a testbed to benchmark particle-in-cell simulations

Author: Yang, L., (0000-0003-1184-2097) Huang, L., (0000-0002-6928-2048) Assenbaum, S., (0000-0002-5845-000X) Cowan, T., Göthel, I., Göde, S., (0000-0003-4861-5584) Kluge, T., (0000-0001-6200-6406) Rehwald, M., Pan, X., (0000-0003-0390-7671) Schramm, U., (0000-0001-5926-9192) Vorberger, J., (0000-0003-3926-409X) Zeil, K., (0000-0002-3727-7017) Ziegler, T., (0000-0003-1739-0159) Bernert, C., Yang, L., (0000-0003-1184-2097) Huang, L., (0000-0002-6928-2048) Assenbaum, S., (0000-0002-5845-000X) Cowan, T., Göthel, I., Göde, S., (0000-0003-4861-5584) Kluge, T., (0000-0001-6200-6406) Rehwald, M., Pan, X., (0000-0003-0390-7671) Schramm, U., (0000-0001-5926-9192) Vorberger, J., (0000-0003-3926-409X) Zeil, K., (0000-0002-3727-7017) Ziegler, T., and (0000-0003-1739-0159) Bernert, C.
Abstract: Particle-in-cell (PIC) simulations are a widely-used tool to model kinetics-dominated plasmas in ultrarelativistic laser-solid interactions (dimensionless vectorpotential a0 > 1). However, interactions approaching subrelativistic laser intensities (a0 ≲ 1) are governed by correlated and collisional plasma physics, calling for benchmarks of available modeling capabilities and the establishment of standardized testbeds. Here, we propose such a testbed to experimentally benchmark PIC simulations of laser-solid interactions using a laser-irradiated micron-sized cryogenic hydrogen-jet target. Time-resolved optical shadowgraphy of the expanding plasma density, complemented by hydrodynamics and ray-tracing simulations, is used to determine the bulk-electron-temperature evolution after laser irradiation. We showcase our testbed by studying isochoric heating of solid hydrogen induced by laser pulses with a dimensionless vectorpotential of a0 ≈ 1. Our testbed reveals that the initial surface-density gradient of the target is decisive to reach quantitative agreement at 1 ps after the interaction, demonstrating its suitability to benchmark controlled parameter scans at subrelativistic laser intensities.
Published: 2023

10. Dosimetry for radiobiological in-vivo experiments at laser plasma-based proton accelerators

Author: (0000-0003-4962-2153) Reimold, M., (0000-0002-6928-2048) Assenbaum, S., (0000-0003-1739-0159) Bernert, C., (0000-0002-0582-1444) Beyreuther, E., (0000-0002-9859-2408) Brack, F.-E., Karsch, L., (0000-0002-0638-6990) Kraft, S., (0000-0002-0275-9892) Kroll, F., Nossula, A., (0000-0003-4128-5498) Pawelke, J., (0000-0001-6200-6406) Rehwald, M., (0000-0003-4400-1315) Schlenvoigt, H.-P., (0000-0003-0390-7671) Schramm, U., (0000-0001-7332-7395) Umlandt, M. E. P., (0000-0003-3926-409X) Zeil, K., (0000-0002-3727-7017) Ziegler, T., (0000-0002-9556-0662) Metzkes-Ng, J., (0000-0003-4962-2153) Reimold, M., (0000-0002-6928-2048) Assenbaum, S., (0000-0003-1739-0159) Bernert, C., (0000-0002-0582-1444) Beyreuther, E., (0000-0002-9859-2408) Brack, F.-E., Karsch, L., (0000-0002-0638-6990) Kraft, S., (0000-0002-0275-9892) Kroll, F., Nossula, A., (0000-0003-4128-5498) Pawelke, J., (0000-0001-6200-6406) Rehwald, M., (0000-0003-4400-1315) Schlenvoigt, H.-P., (0000-0003-0390-7671) Schramm, U., (0000-0001-7332-7395) Umlandt, M. E. P., (0000-0003-3926-409X) Zeil, K., (0000-0002-3727-7017) Ziegler, T., and (0000-0002-9556-0662) Metzkes-Ng, J.
Abstract: Laser plasma-based proton accelerators (LPA) can contribute to research of ultra-high dose rate radiobiology as they provide pulse dose rates unprecedented at medical proton sources. Yet, LPAs pose challenges regarding precise dosimetry due to the high pulse dose rates, but also due to the sources' lower spectral stability and pulsed operation mode. For in-vivo models, further challenges arise from the necessary small field dosimetry for volumetric dose distributions. In this work, we present a dosimetry and beam monitoring concept for in-vivo irradiations of small target volumes with LPA protons, solving aforementioned challenges. The volumetric dose distribution in a sample (mean dose value and lateral/depth dose inhomogeneity) is provided by combining two independent dose measurements using radiochromic films (dose-rate independent) and ionization chambers (dose-rate dependent), respectively. The unique feature of the dosimetric setup is beam monitoring with a transmission time-of-flight spectrometer to quantify spectral fluctuations of the irradiating proton pulses. The resulting changes in the depth dose profile during irradiation of an in-vivo sample are hence accessible and enable pulse-resolved depth dose correction for each dose measurement. A first successful small animal pilot study using an LPA proton source serves as a testcase for the presented dosimetry approach and proves its performance in a realistic setting.
Published: 2023

11. The DRESDEN PLATFORM – A Research Hub for Ultra-high Dose Rate Radiobiology

Author: (0000-0002-9556-0662) Metzkes-Ng, J., (0000-0002-9859-2408) Brack, F.-E., (0000-0002-0275-9892) Kroll, F., (0000-0003-1739-0159) Bernert, C., (0000-0002-1919-8585) Bock, S., (0000-0001-8205-8422) Bodenstein, E., Brand, M., (0000-0002-5845-000X) Cowan, T., Gebhardt, R., Hans, S., Helbig, U., (0000-0003-0707-0856) Horst, F. E., Jansen, J., (0000-0002-0638-6990) Kraft, S., (0000-0003-1776-9556) Krause, M., Leßmann, E., (0000-0002-7017-3738) Löck, S., (0000-0003-4128-5498) Pawelke, J., (0000-0002-4738-6436) Püschel, T., (0000-0003-4962-2153) Reimold, M., (0000-0001-6200-6406) Rehwald, M., (0000-0003-4261-4214) Richter, C., (0000-0003-4400-1315) Schlenvoigt, H.-P., (0000-0003-0390-7671) Schramm, U., Schürer, M., Seco, J., Szabó, E. R., (0000-0001-7332-7395) Umlandt, M. E. P., (0000-0003-3926-409X) Zeil, K., (0000-0002-3727-7017) Ziegler, T., (0000-0002-0582-1444) Beyreuther, E., (0000-0002-9556-0662) Metzkes-Ng, J., (0000-0002-9859-2408) Brack, F.-E., (0000-0002-0275-9892) Kroll, F., (0000-0003-1739-0159) Bernert, C., (0000-0002-1919-8585) Bock, S., (0000-0001-8205-8422) Bodenstein, E., Brand, M., (0000-0002-5845-000X) Cowan, T., Gebhardt, R., Hans, S., Helbig, U., (0000-0003-0707-0856) Horst, F. E., Jansen, J., (0000-0002-0638-6990) Kraft, S., (0000-0003-1776-9556) Krause, M., Leßmann, E., (0000-0002-7017-3738) Löck, S., (0000-0003-4128-5498) Pawelke, J., (0000-0002-4738-6436) Püschel, T., (0000-0003-4962-2153) Reimold, M., (0000-0001-6200-6406) Rehwald, M., (0000-0003-4261-4214) Richter, C., (0000-0003-4400-1315) Schlenvoigt, H.-P., (0000-0003-0390-7671) Schramm, U., Schürer, M., Seco, J., Szabó, E. R., (0000-0001-7332-7395) Umlandt, M. E. P., (0000-0003-3926-409X) Zeil, K., (0000-0002-3727-7017) Ziegler, T., and (0000-0002-0582-1444) Beyreuther, E.
Abstract: The recently observed FLASH effect provides normal tissue protection at a similar tumor treatment efficacy via ultra-high dose rate (UHDR) irradiation and promises great benefits for radiotherapy patients. Dedicated studies are now necessary to define a robust set of dose application parameters for FLASH radiotherapy and to identify underlying mechanisms. These studies require particle accelerators with variable temporal dose application characteristics for numerous radiation qualities, equipped for preclinical radiobiological research. Here we present the DRESDEN PLATFORM, a research hub for ultra-high dose rate radiobiology. By uniting clinical and research accelerators with radiobiology infrastructure and know-how, the DRESDEN PLATFORM offers a unique environment for studying the FLASH effect. We introduce its experimental capabilities and qualify the platform for systematic investigation of FLASH by presenting results from a concerted in vivo radiobiology study with zebrafish embryos. The comparative pre-clinical study was conducted across three accelerator facilities, including an advanced laser-driven proton source applied for FLASH-relevant in vivo irradiations for the first time. The data show a protective effect of UHDR irradiation up to 10^5 Gy/s and suggests consistency of the protective effect even at escalated dose rates of 10^9 Gy/s. With the first clinical FLASH studies underway, research facilities like the DRESDEN PLATFORM, addressing the open questions surrounding FLASH, are essential to accelerate FLASH’s translation into clinical practice.
Published: 2023

12. Ultra-short pulse laser acceleration of protons to 80 MeV from cryogenic hydrogen jets tailored to near-critical density

Author: (0000-0001-6200-6406) Rehwald, M., (0000-0002-6928-2048) Assenbaum, S., (0000-0003-1739-0159) Bernert, C., (0000-0002-9859-2408) Brack, F.-E., (0000-0002-8258-3881) Bussmann, M., (0000-0002-5845-000X) Cowan, T., Curry, C. B., Fiuza, F., Garten, M., (0000-0002-6914-4083) Gaus, L., Gauthier, M., Göde, S., Göthel, I., Glenzer, S. H., (0000-0003-1184-2097) Huang, L., Huebl, A., Kim, J. B., (0000-0003-4861-5584) Kluge, T., (0000-0002-0638-6990) Kraft, S., (0000-0002-0275-9892) Kroll, F., (0000-0002-9556-0662) Metzkes-Ng, J., Miethlinger, T., (0000-0001-7858-0007) Löser, M., Obst-Huebl, L., (0000-0003-4962-2153) Reimold, M., (0000-0003-4400-1315) Schlenvoigt, H.-P., Schoenwaelder, C., (0000-0003-0390-7671) Schramm, U., (0000-0002-4697-3014) Siebold, M., Treffert, F., Yang, L., (0000-0002-3727-7017) Ziegler, T., (0000-0003-3926-409X) Zeil, K., (0000-0001-6200-6406) Rehwald, M., (0000-0002-6928-2048) Assenbaum, S., (0000-0003-1739-0159) Bernert, C., (0000-0002-9859-2408) Brack, F.-E., (0000-0002-8258-3881) Bussmann, M., (0000-0002-5845-000X) Cowan, T., Curry, C. B., Fiuza, F., Garten, M., (0000-0002-6914-4083) Gaus, L., Gauthier, M., Göde, S., Göthel, I., Glenzer, S. H., (0000-0003-1184-2097) Huang, L., Huebl, A., Kim, J. B., (0000-0003-4861-5584) Kluge, T., (0000-0002-0638-6990) Kraft, S., (0000-0002-0275-9892) Kroll, F., (0000-0002-9556-0662) Metzkes-Ng, J., Miethlinger, T., (0000-0001-7858-0007) Löser, M., Obst-Huebl, L., (0000-0003-4962-2153) Reimold, M., (0000-0003-4400-1315) Schlenvoigt, H.-P., Schoenwaelder, C., (0000-0003-0390-7671) Schramm, U., (0000-0002-4697-3014) Siebold, M., Treffert, F., Yang, L., (0000-0002-3727-7017) Ziegler, T., and (0000-0003-3926-409X) Zeil, K.
Abstract: Laser plasma-based particle accelerators attract great interest in fields where conventional accelerators reach limits based on size, cost or beam parameters. Despite the fact that particle in cell simulations have predicted several advantageous ion acceleration schemes, laser accelerators have not yet reached their full potential in producing simultaneous high-radiation doses at high particle energies. The most stringent limitation is the lack of a suitable high-repetition rate target that also provides a high degree of control of the plasma conditions required to access these advanced regimes. Here, we demonstrate that the interaction of petawatt-class laser pulses with a pre-formed micrometer-sized cryogenic hydrogen jet plasma overcomes these limitations enabling tailored density scans from the solid to the underdense regime. Our proof-of-concept experiment demonstrates that the near-critical plasma density profile produces proton energies of up to 80 MeV. Based on hydrodynamic and three-dimensional particle in cell simulations, transition between different acceleration schemes are shown, suggesting enhanced proton acceleration at the relativistic transparency front for the optimal case.
Published: 2023

13. Transient Laser-Induced Breakdown of Dielectrics in Ultrarelativistic Laser-Solid Interactions

Author: (0000-0003-1739-0159) Bernert, C., (0000-0002-6928-2048) Assenbaum, S., (0000-0002-1919-8585) Bock, S., (0000-0002-9859-2408) Brack, F.-E., (0000-0002-5845-000X) Cowan, T., Curry, C. B., (0000-0001-6994-2475) Garten, M., (0000-0002-6914-4083) Gaus, L., Gauthier, M., Gebhardt, R., GöDe, S., Glenzer, S. H., Helbig, U., (0000-0003-4861-5584) Kluge, T., (0000-0002-0638-6990) Kraft, S., (0000-0002-0275-9892) Kroll, F., Obst-Huebl, L., (0000-0002-4738-6436) Püschel, T., (0000-0001-6200-6406) Rehwald, M., (0000-0003-4400-1315) Schlenvoigt, H.-P., Schoenwaelder, C., (0000-0003-0390-7671) Schramm, U., Treffert, F., (0000-0002-2828-5373) Vescovi Pinochet, M. A., (0000-0002-3727-7017) Ziegler, T., (0000-0003-3926-409X) Zeil, K., (0000-0003-1739-0159) Bernert, C., (0000-0002-6928-2048) Assenbaum, S., (0000-0002-1919-8585) Bock, S., (0000-0002-9859-2408) Brack, F.-E., (0000-0002-5845-000X) Cowan, T., Curry, C. B., (0000-0001-6994-2475) Garten, M., (0000-0002-6914-4083) Gaus, L., Gauthier, M., Gebhardt, R., GöDe, S., Glenzer, S. H., Helbig, U., (0000-0003-4861-5584) Kluge, T., (0000-0002-0638-6990) Kraft, S., (0000-0002-0275-9892) Kroll, F., Obst-Huebl, L., (0000-0002-4738-6436) Püschel, T., (0000-0001-6200-6406) Rehwald, M., (0000-0003-4400-1315) Schlenvoigt, H.-P., Schoenwaelder, C., (0000-0003-0390-7671) Schramm, U., Treffert, F., (0000-0002-2828-5373) Vescovi Pinochet, M. A., (0000-0002-3727-7017) Ziegler, T., and (0000-0003-3926-409X) Zeil, K.
Abstract: For high-intensity laser-solid interactions, the absolute density and surface density gradients of the target at the arrival of the ultra-relativistic laser peak are critical parameters. Accurate modeling of the leading edge-driven target pre-expansion is desired to strengthen the predictive power of associated computer simulations. The transition from an initial solid state to a plasma state, i.e., the breakdown of the solid, defines the starting point of the subsequent target pre-expansion. In this work, we report on the time-resolved observation of transient laser-induced breakdown (LIB) during the leading edge of high-intensity petawatt-class laser pulses with peak intensities of up to 5.7 × 10^21 W/cm^2 in interaction with dielectric cryogenic hydrogen jet targets. LIB occurs much earlier than what is typically expected following the concept of barrier suppression ionization. The observation is explained by comparing a characterization study of target specific LIB thresholds with laser contrast measurements. The results demonstrate the relevance of the laser pulse duration dependence of LIB for high-intensity laser-solid interactions. We provide an effective approach to determine the onset of LIB and thereby the starting point of target pre-expansion in other laser-target systems.
Published: 2023

14. Optimizing PW Laser-Driven Proton Acceleration by Characterizing Laser Transmission of Relativistically Transparent Targets

Author: (0000-0001-7332-7395) Umlandt, M. E. P., (0000-0002-6928-2048) Assenbaum, S., (0000-0003-1739-0159) Bernert, C., (0000-0002-1919-8585) Bock, S., (0000-0002-9859-2408) Brack, F.-E., (0000-0002-5845-000X) Cowan, T., Ditter, E. J., Dover, N. P., (0000-0001-6994-2475) Garten, M., (0000-0002-6914-4083) Gaus, L., Göthel, I., Hicks, G. S., Kiriyama, H., (0000-0003-4861-5584) Kluge, T., (0000-0002-7231-0206) Koga, J. K., Kon, A., Kondo, K., (0000-0002-0638-6990) Kraft, S., (0000-0002-0275-9892) Kroll, F., Lowe, H. F., (0000-0002-9556-0662) Metzkes-Ng, J., Miyatake, T., Najmudin, Z., (0000-0001-8143-0827) Nishiuchi, M., (0000-0002-4738-6436) Püschel, T., (0000-0001-6200-6406) Rehwald, M., (0000-0003-4962-2153) Reimold, M., Sakaki, H., (0000-0003-4400-1315) Schlenvoigt, H.-P., Shiokawa, K., (0000-0003-3926-409X) Zeil, K., (0000-0002-3727-7017) Ziegler, T., (0000-0003-0390-7671) Schramm, U., (0000-0001-7332-7395) Umlandt, M. E. P., (0000-0002-6928-2048) Assenbaum, S., (0000-0003-1739-0159) Bernert, C., (0000-0002-1919-8585) Bock, S., (0000-0002-9859-2408) Brack, F.-E., (0000-0002-5845-000X) Cowan, T., Ditter, E. J., Dover, N. P., (0000-0001-6994-2475) Garten, M., (0000-0002-6914-4083) Gaus, L., Göthel, I., Hicks, G. S., Kiriyama, H., (0000-0003-4861-5584) Kluge, T., (0000-0002-7231-0206) Koga, J. K., Kon, A., Kondo, K., (0000-0002-0638-6990) Kraft, S., (0000-0002-0275-9892) Kroll, F., Lowe, H. F., (0000-0002-9556-0662) Metzkes-Ng, J., Miyatake, T., Najmudin, Z., (0000-0001-8143-0827) Nishiuchi, M., (0000-0002-4738-6436) Püschel, T., (0000-0001-6200-6406) Rehwald, M., (0000-0003-4962-2153) Reimold, M., Sakaki, H., (0000-0003-4400-1315) Schlenvoigt, H.-P., Shiokawa, K., (0000-0003-3926-409X) Zeil, K., (0000-0002-3727-7017) Ziegler, T., and (0000-0003-0390-7671) Schramm, U.
Abstract: Ion acceleration by compact laser-plasma sources has great potential for a range of applications, including those with medical relevance and fusion experiments. However, in order to achieve the necessary beam quality parameters for these applications, a thorough understanding and control over the laser-plasma interaction process is required. Therefore, we are exploring laser plasma acceleration around the promising regime of Relativistically Induced Transparency (RIT) through joint studies at DRACO PW (HZDR) and the J-KAREN-P laser system at KPSI. We have performed thickness scans to investigate the relation between proton acceleration performance and target transparency, revealing high-performance proton beams (> 60 MeV) in an expanded foil case, with an optimum at the onset of target transparency. [1] Subsequent experiments showed even higher proton energies. Clearly, the relationship between the transparency onset time and the acceleration performance is crucial for achieving optimal beam parameters, improving our understanding of the sensitivity of laser input parameters, and increasing the process’s robustness. Thus, we are using a combination of particle and laser diagnostics to investigate this correlation. In this contribution, we present a summary of our studies in which we use spectral interferometry with the unperturbed laser beam as a reference to evaluate the output of reflected and transmitted light diagnostics. Obtaining features like shown in Bagnoud et al. [2] and Williamson et al. [3], we additionally correlate these measures with the proton acceleration performance and show first results of spectral, spatial, and energy analysis of the effects on the laser transmission through the target. References [1] Dover, N. P. et al.: Enhanced ion acceleration from transparency-driven foils demonstrated at two ultraintense laser facilities. Light Sci. Appl. in press (2023). [2] Bagnoud, V. et al.: Studying the Dynamics of Relativistic Laser-Plasma Interactio
Published: 2023

15. Laser Transmission in the Relativistically Induced Transparency Regime for High Performance Proton Acceleration at PW Laser Systems

Author: (0000-0001-7332-7395) Umlandt, M. E. P., (0000-0002-6928-2048) Assenbaum, S., (0000-0003-1739-0159) Bernert, C., (0000-0002-1919-8585) Bock, S., (0000-0002-9859-2408) Brack, F.-E., (0000-0002-5845-000X) Cowan, T., Ditter, E. J., Dover, N. P., (0000-0001-6994-2475) Garten, M., (0000-0002-6914-4083) Gaus, L., Göthel, I., Hicks, G. S., Kiriyama, H., (0000-0003-4861-5584) Kluge, T., (0000-0002-7231-0206) Koga, J. K., Kon, A., Kondo, K., (0000-0002-0638-6990) Kraft, S., (0000-0002-0275-9892) Kroll, F., Lowe, H. F., (0000-0002-9556-0662) Metzkes-Ng, J., Miyatake, T., Najmudin, Z., (0000-0001-8143-0827) Nishiuchi, M., (0000-0002-4738-6436) Püschel, T., (0000-0001-6200-6406) Rehwald, M., (0000-0003-4962-2153) Reimold, M., Sakaki, H., (0000-0003-4400-1315) Schlenvoigt, H.-P., Shiokawa, K., (0000-0003-3926-409X) Zeil, K., (0000-0002-3727-7017) Ziegler, T., (0000-0003-0390-7671) Schramm, U., (0000-0001-7332-7395) Umlandt, M. E. P., (0000-0002-6928-2048) Assenbaum, S., (0000-0003-1739-0159) Bernert, C., (0000-0002-1919-8585) Bock, S., (0000-0002-9859-2408) Brack, F.-E., (0000-0002-5845-000X) Cowan, T., Ditter, E. J., Dover, N. P., (0000-0001-6994-2475) Garten, M., (0000-0002-6914-4083) Gaus, L., Göthel, I., Hicks, G. S., Kiriyama, H., (0000-0003-4861-5584) Kluge, T., (0000-0002-7231-0206) Koga, J. K., Kon, A., Kondo, K., (0000-0002-0638-6990) Kraft, S., (0000-0002-0275-9892) Kroll, F., Lowe, H. F., (0000-0002-9556-0662) Metzkes-Ng, J., Miyatake, T., Najmudin, Z., (0000-0001-8143-0827) Nishiuchi, M., (0000-0002-4738-6436) Püschel, T., (0000-0001-6200-6406) Rehwald, M., (0000-0003-4962-2153) Reimold, M., Sakaki, H., (0000-0003-4400-1315) Schlenvoigt, H.-P., Shiokawa, K., (0000-0003-3926-409X) Zeil, K., (0000-0002-3727-7017) Ziegler, T., and (0000-0003-0390-7671) Schramm, U.
Abstract: Ion acceleration by laser-plasma sources promises many applications, but reaching the required beam quality parameters demands a high level of understanding and control over the interaction process. Several advanced schemes, including the Relativistically Induced Transparency (RIT) regime, have been proposed and investigated in search of a stable acceleration for proton energies beyond 100 MeV. In the RIT scheme, the absorption of the electromagnetic laser field by the target and the generated plasma is critical. In joint experiments at the DRACO PW (HZDR) and J-KAREN (KPSI) lasers, we use transmission diagnostics to study the onset of transparency and learn about the sensitivity of the laser input to improve the process’s robustness. Using ultra-short pulses on thin solid density foil targets, we observe high performance proton beams in an expanded foil case. Our analysis of the effects on the transmission and its correlation with the acceleration performance indicates changes in the plasma interaction process.
Published: 2023

16. Laser Transmission in the Relativistically Induced Transparency Regime for High Performance Proton Acceleration at PW Laser Systems

Author: (0000-0001-7332-7395) Umlandt, M. E. P., (0000-0002-6928-2048) Assenbaum, S., (0000-0003-1739-0159) Bernert, C., (0000-0002-1919-8585) Bock, S., (0000-0002-9859-2408) Brack, F.-E., (0000-0002-5845-000X) Cowan, T., Ditter, E. J., Dover, N. P., (0000-0001-6994-2475) Garten, M., (0000-0002-6914-4083) Gaus, L., Göthel, I., Hicks, G. S., Kiriyama, H., (0000-0003-4861-5584) Kluge, T., (0000-0002-7231-0206) Koga, J. K., Kon, A., Kondo, K., (0000-0002-0638-6990) Kraft, S., (0000-0002-0275-9892) Kroll, F., Lowe, H. F., (0000-0002-9556-0662) Metzkes-Ng, J., Miyatake, T., Najmudin, Z., (0000-0001-8143-0827) Nishiuchi, M., (0000-0002-4738-6436) Püschel, T., (0000-0001-6200-6406) Rehwald, M., (0000-0003-4962-2153) Reimold, M., Sakaki, H., (0000-0003-4400-1315) Schlenvoigt, H.-P., Shiokawa, K., (0000-0003-3926-409X) Zeil, K., (0000-0002-3727-7017) Ziegler, T., (0000-0003-0390-7671) Schramm, U., (0000-0001-7332-7395) Umlandt, M. E. P., (0000-0002-6928-2048) Assenbaum, S., (0000-0003-1739-0159) Bernert, C., (0000-0002-1919-8585) Bock, S., (0000-0002-9859-2408) Brack, F.-E., (0000-0002-5845-000X) Cowan, T., Ditter, E. J., Dover, N. P., (0000-0001-6994-2475) Garten, M., (0000-0002-6914-4083) Gaus, L., Göthel, I., Hicks, G. S., Kiriyama, H., (0000-0003-4861-5584) Kluge, T., (0000-0002-7231-0206) Koga, J. K., Kon, A., Kondo, K., (0000-0002-0638-6990) Kraft, S., (0000-0002-0275-9892) Kroll, F., Lowe, H. F., (0000-0002-9556-0662) Metzkes-Ng, J., Miyatake, T., Najmudin, Z., (0000-0001-8143-0827) Nishiuchi, M., (0000-0002-4738-6436) Püschel, T., (0000-0001-6200-6406) Rehwald, M., (0000-0003-4962-2153) Reimold, M., Sakaki, H., (0000-0003-4400-1315) Schlenvoigt, H.-P., Shiokawa, K., (0000-0003-3926-409X) Zeil, K., (0000-0002-3727-7017) Ziegler, T., and (0000-0003-0390-7671) Schramm, U.
Abstract: Ion acceleration by laser-plasma sources promises many applications, but reaching the required beam quality parameters demands a high level of understanding and control over the interaction process. Several advanced schemes, including the Relativistically Induced Transparency (RIT) regime, have been proposed and investigated in search of a stable acceleration for proton energies beyond 100 MeV. In the RIT scheme, the absorption of the electromagnetic laser field by the target and the generated plasma is critical. In joint experiments at the DRACO PW (HZDR) and J-KAREN (KPSI) lasers, we use transmission diagnostics to study the onset of transparency and learn about the sensitivity of the laser input to improve the process’s robustness. Using ultra-short pulses on thin solid density foil targets, we observe high performance proton beams in an expanded foil case. Our analysis of the effects on the transmission and its correlation with the acceleration performance indicates changes in the plasma interaction process.
Published: 2023

17. Data publication: The DRESDEN PLATFORM – A Research Hub for Ultra-high Dose Rate Radiobiology

Author: (0000-0002-9556-0662) Metzkes-Ng, J., (0000-0002-9859-2408) Brack, F.-E., (0000-0002-0275-9892) Kroll, F., (0000-0003-1739-0159) Bernert, C., (0000-0002-1919-8585) Bock, S., (0000-0001-8205-8422) Bodenstein, E., Brand, M., (0000-0002-5845-000X) Cowan, T., Gebhardt, R., Hans, S., Helbig, U., (0000-0003-0707-0856) Horst, F. E., Jansen, J., (0000-0002-0638-6990) Kraft, S., (0000-0003-1776-9556) Krause, M., Leßmann, E., (0000-0002-7017-3738) Löck, S., (0000-0003-4128-5498) Pawelke, J., (0000-0002-4738-6436) Püschel, T., (0000-0003-4962-2153) Reimold, M., (0000-0001-6200-6406) Rehwald, M., (0000-0003-4261-4214) Richter, C., (0000-0003-4400-1315) Schlenvoigt, H.-P., (0000-0003-0390-7671) Schramm, U., Schürer, M., Seco, J., Szabó, E. R., (0000-0001-7332-7395) Umlandt, M. E. P., (0000-0003-3926-409X) Zeil, K., (0000-0002-3727-7017) Ziegler, T., (0000-0002-0582-1444) Beyreuther, E., (0000-0002-9556-0662) Metzkes-Ng, J., (0000-0002-9859-2408) Brack, F.-E., (0000-0002-0275-9892) Kroll, F., (0000-0003-1739-0159) Bernert, C., (0000-0002-1919-8585) Bock, S., (0000-0001-8205-8422) Bodenstein, E., Brand, M., (0000-0002-5845-000X) Cowan, T., Gebhardt, R., Hans, S., Helbig, U., (0000-0003-0707-0856) Horst, F. E., Jansen, J., (0000-0002-0638-6990) Kraft, S., (0000-0003-1776-9556) Krause, M., Leßmann, E., (0000-0002-7017-3738) Löck, S., (0000-0003-4128-5498) Pawelke, J., (0000-0002-4738-6436) Püschel, T., (0000-0003-4962-2153) Reimold, M., (0000-0001-6200-6406) Rehwald, M., (0000-0003-4261-4214) Richter, C., (0000-0003-4400-1315) Schlenvoigt, H.-P., (0000-0003-0390-7671) Schramm, U., Schürer, M., Seco, J., Szabó, E. R., (0000-0001-7332-7395) Umlandt, M. E. P., (0000-0003-3926-409X) Zeil, K., (0000-0002-3727-7017) Ziegler, T., and (0000-0002-0582-1444) Beyreuther, E.
Abstract: Source data, scripts and parts of figures to generate the figures in publication
Published: 2023

18. Source Data: Ultra-short pulse laser acceleration of protons to 80 MeV from cryogenic hydrogen jets tailored to near-critical density

Author: (0000-0001-6200-6406) Rehwald, M., (0000-0002-6928-2048) Assenbaum, S., (0000-0003-1739-0159) Bernert, C., (0000-0002-9859-2408) Brack, F.-E., (0000-0002-8258-3881) Bussmann, M., (0000-0002-5845-000X) Cowan, T., (0000-0001-8756-181X) Curry, C. B., (0000-0002-8502-5535) Fiuza, F., (0000-0001-6994-2475) Garten, M., (0000-0002-6914-4083) Gaus, L., (0000-0001-6608-9325) Gauthier, M., Göde, S., Göthel, I., (0000-0001-9112-0558) Glenzer, S. H., (0000-0003-1184-2097) Huang, L., (0000-0003-1943-7141) Hübl, A., Kim, J. B., (0000-0003-4861-5584) Kluge, T., (0000-0002-0638-6990) Kraft, S., (0000-0002-0275-9892) Kroll, F., (0000-0002-9556-0662) Metzkes-Ng, J., Miethlinger, T., (0000-0001-7858-0007) Löser, M., (0000-0001-9236-8037) Obst-Huebl, L., (0000-0003-4962-2153) Reimold, M., (0000-0003-4400-1315) Schlenvoigt, H.-P., (0000-0002-6181-4054) Schoenwaelder, C., (0000-0003-0390-7671) Schramm, U., (0000-0002-4697-3014) Siebold, M., (0000-0003-1277-4241) Treffert, F., Yang, L., (0000-0002-3727-7017) Ziegler, T., (0000-0003-3926-409X) Zeil, K., (0000-0001-6200-6406) Rehwald, M., (0000-0002-6928-2048) Assenbaum, S., (0000-0003-1739-0159) Bernert, C., (0000-0002-9859-2408) Brack, F.-E., (0000-0002-8258-3881) Bussmann, M., (0000-0002-5845-000X) Cowan, T., (0000-0001-8756-181X) Curry, C. B., (0000-0002-8502-5535) Fiuza, F., (0000-0001-6994-2475) Garten, M., (0000-0002-6914-4083) Gaus, L., (0000-0001-6608-9325) Gauthier, M., Göde, S., Göthel, I., (0000-0001-9112-0558) Glenzer, S. H., (0000-0003-1184-2097) Huang, L., (0000-0003-1943-7141) Hübl, A., Kim, J. B., (0000-0003-4861-5584) Kluge, T., (0000-0002-0638-6990) Kraft, S., (0000-0002-0275-9892) Kroll, F., (0000-0002-9556-0662) Metzkes-Ng, J., Miethlinger, T., (0000-0001-7858-0007) Löser, M., (0000-0001-9236-8037) Obst-Huebl, L., (0000-0003-4962-2153) Reimold, M., (0000-0003-4400-1315) Schlenvoigt, H.-P., (0000-0002-6181-4054) Schoenwaelder, C., (0000-0003-0390-7671) Schramm, U., (0000-0002-4697-3014) Siebold, M., (0000-0003-1277-4241) Treffert, F., Yang, L., (0000-0002-3727-7017) Ziegler, T., and (0000-0003-3926-409X) Zeil, K.
Abstract: Data for all figures of publication: " Ultra-short pulse laser acceleration of protons to 80 MeV from cryogenic hydrogen jets tailored to near-critical density". The folder structure is adapted to match the figures in the publication.
Published: 2023

19. Enhanced ion acceleration from transparency-driven foils demonstrated at two ultraintense laser facilities

Author: Dover, N. P., (0000-0002-3727-7017) Ziegler, T., (0000-0002-6928-2048) Assenbaum, S., (0000-0003-1739-0159) Bernert, C., (0000-0002-1919-8585) Bock, S., (0000-0002-9859-2408) Brack, F.-E., (0000-0002-5845-000X) Cowan, T., Ditter, E. J., Garten, M., Gaus, L., Göthel, I., Hicks, G. S., Kiriyama, H., (0000-0003-4861-5584) Kluge, T., Koga, J. K., Kon, A., Kondo, K., (0000-0002-0638-6990) Kraft, S., (0000-0002-0275-9892) Kroll, F., Lowe, H. F., (0000-0002-9556-0662) Metzkes-Ng, J., Miyatake, T., Najmudin, Z., (0000-0002-4738-6436) Püschel, T., (0000-0001-6200-6406) Rehwald, M., Reimold, M., Sakaki, H., (0000-0003-4400-1315) Schlenvoigt, H.-P., Shiokawa, K., (0000-0001-7332-7395) Umlandt, M. E. P., (0000-0003-0390-7671) Schramm, U., (0000-0003-3926-409X) Zeil, K., Nishiuchi, M., Dover, N. P., (0000-0002-3727-7017) Ziegler, T., (0000-0002-6928-2048) Assenbaum, S., (0000-0003-1739-0159) Bernert, C., (0000-0002-1919-8585) Bock, S., (0000-0002-9859-2408) Brack, F.-E., (0000-0002-5845-000X) Cowan, T., Ditter, E. J., Garten, M., Gaus, L., Göthel, I., Hicks, G. S., Kiriyama, H., (0000-0003-4861-5584) Kluge, T., Koga, J. K., Kon, A., Kondo, K., (0000-0002-0638-6990) Kraft, S., (0000-0002-0275-9892) Kroll, F., Lowe, H. F., (0000-0002-9556-0662) Metzkes-Ng, J., Miyatake, T., Najmudin, Z., (0000-0002-4738-6436) Püschel, T., (0000-0001-6200-6406) Rehwald, M., Reimold, M., Sakaki, H., (0000-0003-4400-1315) Schlenvoigt, H.-P., Shiokawa, K., (0000-0001-7332-7395) Umlandt, M. E. P., (0000-0003-0390-7671) Schramm, U., (0000-0003-3926-409X) Zeil, K., and Nishiuchi, M.
Abstract: Laser-driven ion sources are a rapidly developing technology producing high energy, high peak current beams. Their suitability for applications, such as compact medical accelerators, motivates development of robust acceleration schemes using widely available repetitive ultraintense femtosecond lasers. These applications not only require high beam energy, but also place demanding requirements on the source stability and controllability. This can be seriously affected by the laser temporal contrast, precluding the replication of ion acceleration performance on independent laser systems with otherwise similar parameters. Here, we present the experimental generation of >60 MeV protons and >30 MeV u^{−1} carbon ions from sub-micrometre thickness Formvar foils irradiated with laser intensities >10^{21} W/cm^{2}. Ions are accelerated by an extreme localised space charge field ≳30 TVm^{−1}, over a million times higher than used in conventional accelerators. The field is formed by a rapid expulsion of electrons from the target bulk due to relativistically induced transparency, in which relativistic corrections to the refractive index enables laser transmission through normally opaque plasma. We replicate the mechanism on two different laser facilities and show that the optimum target thickness decreases with improved laser contrast due to reduced pre-expansion. Our demonstration that energetic ions can be accelerated by this mechanism at different contrast levels relaxes laser requirements and indicates interaction parameters for realising application-specific beam delivery.
Published: 2023

20. Cryogenic hydrogen jet platform for quasi-continuous laser proton acceleration from tailored near-critical density targets

Author: (0000-0002-6928-2048) Assenbaum, S., (0000-0003-1739-0159) Bernert, C., (0000-0002-1919-8585) Bock, S., (0000-0001-8756-181X) Curry, C., (0000-0001-6608-9325) Gauthier, M., Gebhardt, R., (0000-0001-9112-0558) Glenzer, S., Göde, S., Helbig, U., (0000-0003-4861-5584) Kluge, T., Loureiro, D., Miethlinger, T., (0000-0002-4738-6436) Püschel, T., (0000-0001-6200-6406) Rehwald, M., Schönwälder, C., (0000-0002-2828-5373) Vescovi Pinochet, M. A., Yang, L., (0000-0003-3926-409X) Zeil, K., (0000-0003-0390-7671) Schramm, U., (0000-0002-6928-2048) Assenbaum, S., (0000-0003-1739-0159) Bernert, C., (0000-0002-1919-8585) Bock, S., (0000-0001-8756-181X) Curry, C., (0000-0001-6608-9325) Gauthier, M., Gebhardt, R., (0000-0001-9112-0558) Glenzer, S., Göde, S., Helbig, U., (0000-0003-4861-5584) Kluge, T., Loureiro, D., Miethlinger, T., (0000-0002-4738-6436) Püschel, T., (0000-0001-6200-6406) Rehwald, M., Schönwälder, C., (0000-0002-2828-5373) Vescovi Pinochet, M. A., Yang, L., (0000-0003-3926-409X) Zeil, K., and (0000-0003-0390-7671) Schramm, U.
Abstract: In this contribution, we present the results of laser-target interaction studies with intensities ranging from the relativistic regime down to the intensities of dielectric breakdown of hydrogen. They were conducted using the cryogenic hydrogen jet platforms together with the high-resolution optical probing capabilities at the Draco laser facility at Helmholtz-Zentrum Dresden-Rossendorf and the HiBEF facility at European XFEL. Changing the laser parameters enables to utilize specific plasma processes for controlled plasma density tailoring. These results, together with technical advancements of the target, pave the way towards a stable platform for near-critical density targets that will enable stable, repetition-rated proton sources for a multitude of applications at superb energies.
Published: 2023

21. Laser-induced breakdown of targets for Laser-ion acceleration

Author: (0000-0002-6928-2048) Assenbaum, S., (0000-0003-1739-0159) Bernert, C., (0000-0001-6200-6406) Rehwald, M., (0000-0003-3926-409X) Zeil, K., (0000-0003-0390-7671) Schramm, U., (0000-0002-6928-2048) Assenbaum, S., (0000-0003-1739-0159) Bernert, C., (0000-0001-6200-6406) Rehwald, M., (0000-0003-3926-409X) Zeil, K., and (0000-0003-0390-7671) Schramm, U.
Abstract: After the interaction of ultra-short high intensity laser pulses with thin solid targets, strong electric fields within the resulting plasma can accelerate ions to energies of tens of MeV. The performance of such laser driven ion sources critically depends on the initial conditions of the target plasma at the arrival time of the driving laser pulse. Pre-pulses and pedestals in the intrinsic temporal laser contrast can cause dielectric breakdown of the target long before the arrival of the main laser pulse, causing the target to ionize and pre-expand uncontrolledly. Here, we present a study of the laser-induced breakdown (LIB) threshold intensity of 300nm thin formvar foils as well as cryogenic solid hydrogen jets, which are both used as targets for ion accleration at the Draco laser facility at Helmholtz-Zentrum Dresden-Rossendorf. By stretching the pump laser pulse, the dependence of LIB threshold intensity on laser pulse duration is investigated. This helps to understand and model the pre-plasma formation during the rising flank of a high power laser pulse impinging on a thin dielectric target.
Published: 2023

22. Investigation of laser-induced breakdown and target pre-expansion for laser proton acceleration

Author: (0000-0002-6928-2048) Assenbaum, S., (0000-0003-1739-0159) Bernert, C., Göde, S., (0000-0003-4861-5584) Kluge, T., Loureiro, D., (0000-0001-6200-6406) Rehwald, M., (0000-0002-2828-5373) Vescovi Pinochet, M. A., Yang, L., (0000-0003-0390-7671) Schramm, U., (0000-0003-3926-409X) Zeil, K., (0000-0002-6928-2048) Assenbaum, S., (0000-0003-1739-0159) Bernert, C., Göde, S., (0000-0003-4861-5584) Kluge, T., Loureiro, D., (0000-0001-6200-6406) Rehwald, M., (0000-0002-2828-5373) Vescovi Pinochet, M. A., Yang, L., (0000-0003-0390-7671) Schramm, U., and (0000-0003-3926-409X) Zeil, K.
Abstract: The upcoming generation of repetition-rate petawatt class lasers drives the development of laser-plasma proton accelerators and enables new applications e.g. in cancer radiotherapy research. To harness the full potential of these laser systems and their applications, it is crucial to characterize and control the density profile of the target at the arrival of the ultra-intense laser peak. Cryogenic solid-density hydrogen jets were successfully demonstrated as a promising target platform to investigate various aspects of the high intensity interaction. In combination with optical and X-ray probing techniques, the unique properties of these jets as self-replenishing, debris free, low-density, pure hydrogen targets provide an ideal test bed to study processes like ionization and pre-expansion that occur during irradiation of the leading edge of the laser pulse. In this contribution, we present the results of laser-target interaction studies with intensities ranging from the relativistic regime down to the intensities of dielectric breakdown of hydrogen. They were conducted using the cryogenic hydrogen jet platform together with the high-resolution optical probing capabilities at the Draco laser facility at Helmholtz-Zentrum Dresden-Rossendorf and the X-ray free electron laser at the HiBEF facility at European XFEL. Changing the drive laser pulse parameters enabled extensive studies, e.g., of the transition from an initial solid state to a plasma state, i.e., the onset of laser-induced breakdown of the solid defining the starting point of the subsequent pre-expansion. As a further example, insights into pre-plasma formation are obtained by investigating the intensity-dependent evolution of the target density profile. These results, together with technical advancements of the target, will be valuable for optimizing laser-driven proton acceleration at high-intensity laser facilities.
Published: 2023

23. Cascaded laser proton acceleration well beyond 100 MeV energy

Author: (0000-0002-3727-7017) Ziegler, T., (0000-0002-6928-2048) Assenbaum, S., (0000-0003-1739-0159) Bernert, C., (0000-0002-9859-2408) Brack, F.-E., (0000-0002-5845-000X) Cowan, T., Dover, N., Garten, M., Gaus, L., Göthel, I., Kiriyama, H., (0000-0003-4861-5584) Kluge, T., (0000-0002-0638-6990) Kraft, S., (0000-0002-0275-9892) Kroll, F., (0000-0002-9556-0662) Metzkes-Ng, J., Nishuichi, M., Reimold, M., (0000-0001-6200-6406) Rehwald, M., (0000-0003-4400-1315) Schlenvoigt, H.-P., (0000-0001-7332-7395) Umlandt, M. E. P., (0000-0002-2828-5373) Vescovi Pinochet, M. A., (0000-0003-0390-7671) Schramm, U., (0000-0003-3926-409X) Zeil, K., (0000-0002-3727-7017) Ziegler, T., (0000-0002-6928-2048) Assenbaum, S., (0000-0003-1739-0159) Bernert, C., (0000-0002-9859-2408) Brack, F.-E., (0000-0002-5845-000X) Cowan, T., Dover, N., Garten, M., Gaus, L., Göthel, I., Kiriyama, H., (0000-0003-4861-5584) Kluge, T., (0000-0002-0638-6990) Kraft, S., (0000-0002-0275-9892) Kroll, F., (0000-0002-9556-0662) Metzkes-Ng, J., Nishuichi, M., Reimold, M., (0000-0001-6200-6406) Rehwald, M., (0000-0003-4400-1315) Schlenvoigt, H.-P., (0000-0001-7332-7395) Umlandt, M. E. P., (0000-0002-2828-5373) Vescovi Pinochet, M. A., (0000-0003-0390-7671) Schramm, U., and (0000-0003-3926-409X) Zeil, K.
Abstract: Laser-driven ion accelerators can deliver high-energy, high peak current beams and are thus attracting attention as a compact alternative to conventional accelerators. However, achieving sufficiently high energy levels suitable for applications such as radiation therapy remains a challenge for laser-driven ion accelerators. Here, we generate proton beams with a spectrally separated high-energy component of up to 150MeV by irradiating solid-density plastic foil targets with ultrashort laser pulses from a repetitive petawatt laser. The preceding laser light heats the target, leading to the onset of relativistically-induced transparency upon main pulse arrival. The laser peak then penetrates the initially opaque target and triggers proton acceleration through a cascade of different mechanisms, as revealed by three-dimensional particle-in-cell simulations. The transparency of the target can be used to identify the high-performance domain, making it a suitable feedback parameter for automated laser and target optimisation to enhance stability of plasma accelerators in the future.
Published: 2023

24. Surpassing TNSA performance in laser proton acceleration in the relativistic transparency regime

Author: (0000-0002-3727-7017) Ziegler, T., (0000-0002-6928-2048) Assenbaum, S., (0000-0003-1739-0159) Bernert, C., (0000-0002-9859-2408) Brack, F.-E., (0000-0002-5845-000X) Cowan, T., Dover, N., Garten, M., Gaus, L., Göthel, I., Kiriyama, H., (0000-0003-4861-5584) Kluge, T., Kon, A., (0000-0002-0638-6990) Kraft, S., (0000-0002-0275-9892) Kroll, F., (0000-0002-9556-0662) Metzkes-Ng, J., Nishuichi, M., (0000-0003-0931-1350) Prencipe, I., (0000-0002-4738-6436) Püschel, T., (0000-0001-6200-6406) Rehwald, M., Reimold, M., (0000-0003-4400-1315) Schlenvoigt, H.-P., (0000-0001-7332-7395) Umlandt, M. E. P., (0000-0002-2828-5373) Vescovi Pinochet, M. A., (0000-0003-0390-7671) Schramm, U., (0000-0003-3926-409X) Zeil, K., (0000-0002-3727-7017) Ziegler, T., (0000-0002-6928-2048) Assenbaum, S., (0000-0003-1739-0159) Bernert, C., (0000-0002-9859-2408) Brack, F.-E., (0000-0002-5845-000X) Cowan, T., Dover, N., Garten, M., Gaus, L., Göthel, I., Kiriyama, H., (0000-0003-4861-5584) Kluge, T., Kon, A., (0000-0002-0638-6990) Kraft, S., (0000-0002-0275-9892) Kroll, F., (0000-0002-9556-0662) Metzkes-Ng, J., Nishuichi, M., (0000-0003-0931-1350) Prencipe, I., (0000-0002-4738-6436) Püschel, T., (0000-0001-6200-6406) Rehwald, M., Reimold, M., (0000-0003-4400-1315) Schlenvoigt, H.-P., (0000-0001-7332-7395) Umlandt, M. E. P., (0000-0002-2828-5373) Vescovi Pinochet, M. A., (0000-0003-0390-7671) Schramm, U., and (0000-0003-3926-409X) Zeil, K.
Abstract: Exploiting the strong electromagnetic fields that can be supported by a plasma, high-power laser driven compact plasma accelerators enable generation of short, high-intensity pulses of high energy ions with special beam properties. These accelerators promise to expand the portfolio of conventional machines in many application areas. The maturation of laser driven ion accelerators from physics experiments to turn-key sources for these applications will rely on breakthroughs in both, generated beam parameters (kinetic energy, flux), as well as increased scrutiny on reproducibility, robustness and scalability to high repetition rate. Recent developments at the high-power laser facility DRACO-PW enabled the production of polychromatic proton beams with unprecedented stability [1]. This allowed the first in vivo radiobiological study to be conducted using a laser-driven proton source [2]. Yet, the ability to achieve energies beyond the 100 MeV frontier is essential for many applications and a matter of ongoing research, mainly addressed by exploring advanced acceleration schemes like the relativistically induced transparency regime. In this talk we report on experimental proton acceleration studies at the onset of relativistic transparency using linearly polarized laser pulses with peak intensities of 6x21 W/cm2 focused on thin, pre-expanded plastic foils. Combined hydrodynamic and 3D particle-in-cell simulations helped to identify the most promising target parameter range matched to the carefully measured prevailing laser contrast conditions. In a nutshell, the ultra-intense femtosecond pulse interaction induces large accelerating gradients and energy gain dominantly arising from significant space charge fields due to electron expulsion from the relativistic transparent target core followed by weaker post-acceleration in diffuse sheath fields at later times. A complex suite of particle and optical diagnostics allowed characterization of spatial and spectral proton beam
Published: 2023

25. Investigation of laser reflectivity and transmissivity of laser-plasma interaction with thin foil targets

Author: (0000-0001-7332-7395) Umlandt, M. E. P., (0000-0002-3727-7017) Ziegler, T., (0000-0003-1739-0159) Bernert, C., (0000-0001-6994-2475) Garten, M., (0000-0002-6914-4083) Gaus, L., Göthel, I., (0000-0003-4861-5584) Kluge, T., (0000-0002-0638-6990) Kraft, S., (0000-0002-0275-9892) Kroll, F., (0000-0002-9556-0662) Metzkes-Ng, J., (0000-0003-0931-1350) Prencipe, I., (0000-0001-6200-6406) Rehwald, M., (0000-0003-4962-2153) Reimold, M., (0000-0003-4400-1315) Schlenvoigt, H.-P., Vescovi Pinochet, M. A., (0000-0003-3926-409X) Zeil, K., (0000-0003-0390-7671) Schramm, U., (0000-0001-7332-7395) Umlandt, M. E. P., (0000-0002-3727-7017) Ziegler, T., (0000-0003-1739-0159) Bernert, C., (0000-0001-6994-2475) Garten, M., (0000-0002-6914-4083) Gaus, L., Göthel, I., (0000-0003-4861-5584) Kluge, T., (0000-0002-0638-6990) Kraft, S., (0000-0002-0275-9892) Kroll, F., (0000-0002-9556-0662) Metzkes-Ng, J., (0000-0003-0931-1350) Prencipe, I., (0000-0001-6200-6406) Rehwald, M., (0000-0003-4962-2153) Reimold, M., (0000-0003-4400-1315) Schlenvoigt, H.-P., Vescovi Pinochet, M. A., (0000-0003-3926-409X) Zeil, K., and (0000-0003-0390-7671) Schramm, U.
Abstract: Ion acceleration by compact laser-plasma sources promises a variety of applications ranging from medical relevance to fusion experiments.Reaching the required beam quality parameters for those applications demands a very high level of understanding and control over the laserplasma interaction process. Central components in this context are the absorption of the electromagnetic laser field by the plasma and the quality of the resulting acceleration field structure. Measuring and analyzing unabsorbed light - as transmitted and/or specularly reflected parts - thus allows insight into properties of the underlying laser-plasma interaction. We experimentally investigate these interactions for high and low-contrast laser pulses with thin solid density foil targets at the Draco PW laser system (HZDR). The results of spectral, spatial, and energy analysis of transmitted and reflected light indicate changes in the plasma interaction and will be presented.
Published: 2022

26. Commissioning and First User Experiments with ReLaX and XFEL Beam

Author: (0000-0002-7671-0901) Laso García, A., Arefiev, A., Kemp, A., Allen, C. H., Bähtz, C., Nagler, B., Palmer, C. A. J., Murphy, C. D., Spindloe, C., Brown, C. R. D., Neely, D., (0000-0002-6350-4180) Kraus, D., Marley, E., Hartouni, E. P., Fiuza, F., Grim, G. P., Cochran, G. E., (0000-0003-4400-1315) Schlenvoigt, H.-P., (0000-0003-0931-1350) Prencipe, I., Williams, J., Green, J., Eggert, J. H., (0000-0003-3926-409X) Zeil, K., Lancaster, K. L., Divol, L., (0000-0002-6914-4083) Gaus, L., (0000-0003-1184-2097) Huang, L., Schoelmerich, M., (0000-0001-6200-6406) Rehwald, M., Oliver, M., Rödel, M., Macdonald, M., (0000-0002-7162-7500) Smid, M., Makita, M., Nakatsutsumi, M., (0000-0001-6748-0422) Humphries, O. S., Neumayer, P. B., Mabey, P., Shepherd, R. L., Gray, R., Wilks, S. C., Le Pape, S., Kerr, S. M., Glenzer, S. H., Funk, S., Gales, S. G., (0000-0002-5845-000X) Cowan, T., White, T. G., (0000-0003-4861-5584) Kluge, T., Doeppner, T., (0000-0001-7986-3631) Toncian, T., Zastrau, U., (0000-0003-0390-7671) Schramm, U., Ping, Y., He, Z., Höppner, H., Pelka, A., (0000-0002-7671-0901) Laso García, A., Arefiev, A., Kemp, A., Allen, C. H., Bähtz, C., Nagler, B., Palmer, C. A. J., Murphy, C. D., Spindloe, C., Brown, C. R. D., Neely, D., (0000-0002-6350-4180) Kraus, D., Marley, E., Hartouni, E. P., Fiuza, F., Grim, G. P., Cochran, G. E., (0000-0003-4400-1315) Schlenvoigt, H.-P., (0000-0003-0931-1350) Prencipe, I., Williams, J., Green, J., Eggert, J. H., (0000-0003-3926-409X) Zeil, K., Lancaster, K. L., Divol, L., (0000-0002-6914-4083) Gaus, L., (0000-0003-1184-2097) Huang, L., Schoelmerich, M., (0000-0001-6200-6406) Rehwald, M., Oliver, M., Rödel, M., Macdonald, M., (0000-0002-7162-7500) Smid, M., Makita, M., Nakatsutsumi, M., (0000-0001-6748-0422) Humphries, O. S., Neumayer, P. B., Mabey, P., Shepherd, R. L., Gray, R., Wilks, S. C., Le Pape, S., Kerr, S. M., Glenzer, S. H., Funk, S., Gales, S. G., (0000-0002-5845-000X) Cowan, T., White, T. G., (0000-0003-4861-5584) Kluge, T., Doeppner, T., (0000-0001-7986-3631) Toncian, T., Zastrau, U., (0000-0003-0390-7671) Schramm, U., Ping, Y., He, Z., Höppner, H., and Pelka, A.
Abstract: In this presentation we provide an overview of the commissioning and first user experiment of ReLaX in combination with the XFEL beam. We will introduce the setup and laser parameters. We will show the established standard setup combining small-angle x-ray scattering (SAXS), phase-contrast imaging (PCI) and spectroscopy techniques. Finally we will show examples of the data obtained in the interaction of the ReLaX laser with targets of interested for the short-pulse laser community.
Published: 2022

27. Tumor irradiation in mice with a laser-accelerated proton beam

Author: (0000-0002-0275-9892) Kroll, F., (0000-0002-9859-2408) Brack, F.-E., (0000-0003-1739-0159) Bernert, C., (0000-0002-1919-8585) Bock, S., Bodenstein, E., Brüchner, K., (0000-0002-5845-000X) Cowan, T., (0000-0002-6914-4083) Gaus, L., Gebhardt, R., Helbig, U., Karsch, L., (0000-0003-4861-5584) Kluge, T., (0000-0002-0638-6990) Kraft, S., (0000-0003-1776-9556) Krause, M., Leßmann, E., (0000-0002-5248-0910) Masood, U., Meister, S., (0000-0002-9556-0662) Metzkes-Ng, J., Nossula, A., (0000-0003-4128-5498) Pawelke, J., (0000-0002-1610-1493) Pietzsch, J., (0000-0002-4738-6436) Püschel, T., (0000-0003-4962-2153) Reimold, M., (0000-0001-6200-6406) Rehwald, M., (0000-0003-4261-4214) Richter, C., (0000-0003-4400-1315) Schlenvoigt, H.-P., (0000-0003-0390-7671) Schramm, U., (0000-0001-7332-7395) Umlandt, M. E. P., (0000-0002-3727-7017) Ziegler, T., (0000-0003-3926-409X) Zeil, K., (0000-0002-0582-1444) Beyreuther, E., (0000-0002-0275-9892) Kroll, F., (0000-0002-9859-2408) Brack, F.-E., (0000-0003-1739-0159) Bernert, C., (0000-0002-1919-8585) Bock, S., Bodenstein, E., Brüchner, K., (0000-0002-5845-000X) Cowan, T., (0000-0002-6914-4083) Gaus, L., Gebhardt, R., Helbig, U., Karsch, L., (0000-0003-4861-5584) Kluge, T., (0000-0002-0638-6990) Kraft, S., (0000-0003-1776-9556) Krause, M., Leßmann, E., (0000-0002-5248-0910) Masood, U., Meister, S., (0000-0002-9556-0662) Metzkes-Ng, J., Nossula, A., (0000-0003-4128-5498) Pawelke, J., (0000-0002-1610-1493) Pietzsch, J., (0000-0002-4738-6436) Püschel, T., (0000-0003-4962-2153) Reimold, M., (0000-0001-6200-6406) Rehwald, M., (0000-0003-4261-4214) Richter, C., (0000-0003-4400-1315) Schlenvoigt, H.-P., (0000-0003-0390-7671) Schramm, U., (0000-0001-7332-7395) Umlandt, M. E. P., (0000-0002-3727-7017) Ziegler, T., (0000-0003-3926-409X) Zeil, K., and (0000-0002-0582-1444) Beyreuther, E.
Abstract: Recent oncological studies identified beneficial properties of radiation applied at ultra-high dose rates several orders of magnitude higher than the clinical standard of the order of Gy/min. Sources capable of providing these ultra-high dose rates are under investigation. Here, we show that a stable, compact laser-driven proton source with energies greater than 60 MeV enables radiobiological in vivo studies. We performed a pilot irradiation study on human tumors in a mouse model, showing the concerted preparation of mice and laser accelerator, the dose-controlled, tumor-conform irradiation using a laser-driven as well as a clinical reference proton source, and the radiobiological evaluation of irradiated and unirradiated mice for radiation-induced tumor growth delay. The prescribed homogeneous dose of 4 Gy was precisely delivered at the laser-driven source. The results demonstrate a complete laser-driven proton research platform for diverse user-specific small animal models, able to deliver tunable single-shot doses up to around 20 Gy to millimeter-scale volumes on nanosecond time scales, equivalent to around 1E9 Gy/s, spatially homogenized and tailored to the sample. The platform provides a unique infrastructure for translational research with protons at ultra-high dose rate.
Published: 2022

28. Laser-plasma based proton accelerators for small animal pre-clinical radiation research

Author: (0000-0002-0275-9892) Kroll, F., (0000-0002-9859-2408) Brack, F.-E., (0000-0003-1739-0159) Bernert, C., (0000-0002-1919-8585) Bock, S., Bodenstein, E., Brüchner, K., (0000-0002-5845-000X) Cowan, T., (0000-0002-6914-4083) Gaus, L., Gebhardt, R., Helbig, U., Karsch, L., (0000-0003-4861-5584) Kluge, T., (0000-0002-0638-6990) Kraft, S., (0000-0003-1776-9556) Krause, M., Leßmann, E., Masood, U., Meister, S., Nossula, A., (0000-0003-4128-5498) Pawelke, J., (0000-0002-1610-1493) Pietzsch, J., (0000-0002-4738-6436) Püschel, T., (0000-0003-4962-2153) Reimold, M., (0000-0001-6200-6406) Rehwald, M., (0000-0003-4261-4214) Richter, C., (0000-0003-4400-1315) Schlenvoigt, H.-P., (0000-0003-0390-7671) Schramm, U., (0000-0001-7332-7395) Umlandt, M. E. P., (0000-0002-3727-7017) Ziegler, T., (0000-0003-3926-409X) Zeil, K., (0000-0002-0582-1444) Beyreuther, E., (0000-0002-9556-0662) Metzkes-Ng, J., (0000-0002-0275-9892) Kroll, F., (0000-0002-9859-2408) Brack, F.-E., (0000-0003-1739-0159) Bernert, C., (0000-0002-1919-8585) Bock, S., Bodenstein, E., Brüchner, K., (0000-0002-5845-000X) Cowan, T., (0000-0002-6914-4083) Gaus, L., Gebhardt, R., Helbig, U., Karsch, L., (0000-0003-4861-5584) Kluge, T., (0000-0002-0638-6990) Kraft, S., (0000-0003-1776-9556) Krause, M., Leßmann, E., Masood, U., Meister, S., Nossula, A., (0000-0003-4128-5498) Pawelke, J., (0000-0002-1610-1493) Pietzsch, J., (0000-0002-4738-6436) Püschel, T., (0000-0003-4962-2153) Reimold, M., (0000-0001-6200-6406) Rehwald, M., (0000-0003-4261-4214) Richter, C., (0000-0003-4400-1315) Schlenvoigt, H.-P., (0000-0003-0390-7671) Schramm, U., (0000-0001-7332-7395) Umlandt, M. E. P., (0000-0002-3727-7017) Ziegler, T., (0000-0003-3926-409X) Zeil, K., (0000-0002-0582-1444) Beyreuther, E., and (0000-0002-9556-0662) Metzkes-Ng, J.
Abstract: Laser-plasma based proton accelerators as a novel accelerator technology have matured to a level at which laboratory-scale setups for the emerging topic of image-guided precision small animal irradiation studies come into reach [Bra2019]. Providing a high proton energy bandwidth [Sch2016] which is filtered in a tunable pulsed magnet beam transport, these accelerators enable flexibility in terms of scattering-free irradiation field formation [Mas2014, Mas2015]. Regarding temporal dose delivery, with single pulse doses reaching the Gy level at unprecedented peak dose rates of up to 1012 Gy/s [Sch2016], laser-plasma based proton accelerator setups can give access to the dose rate regime of FLASH [Fav2014, Voz2019]. The realization of a full-scale setup for image-guided precision radiobiological studies for small animals focusing on dose rate dependent effects is currently prepared at the PENELOPE laser-plasma based proton accelerator at HZDR and will be presented with a focus on the technological requirements and solutions for dose delivery at laser-plasma based sources. This development relies on our experience in performing dose-controlled radiobiological in vitro studies [Kra2010, Zei2013] and first in vivo irradiation experiments at the DRACO laser-plasma based proton accelerator at HZDR, where we have established a pulsed solenoid beamline for 3D irradiation field formation, yielding a (5 mm)³ homogeneous volumetric dose distribution at a Gy single pulse dose level [8]. [Bra2019] F.-E. Brack, F. Kroll, L. Gaus, C. Bernert, E. Beyreuther, T. E. Cowan, L. Karsch, S. D. Kraft, L. A. Kunz-Schughart, E. Lessmann, J. Metzkes-Ng, L. Obst-Hübl, J. Pawelke, M. Rehwald, H.-P. Schlenvoigt, U. Schramm, M. Sobiella, E. R. Szabó, T. Ziegler, K. Zeil, Spectral and spatial shaping of laser-driven proton beams using a pulsed high-field magnet beamline. arXiv:1910.08430 (2019) [Sch2016] J. Schreiber, P. Bolton, K. Parodi, “Hands-on” laser-driven ion acceleration: A primer for laser
Published: 2022

29. Towards High-Repetition Rate Petawatt Laser Experiments with Cryogenic Jets Using a Mechanical Chopper System

Author: (0000-0001-6200-6406) Rehwald, M., Assenbaum, S., (0000-0003-1739-0159) Bernert, C., (0000-0001-8756-181X) Curry, C. B., Gauthier, M., Glenzer, S. H., Göde, S., Schoenwaelder, C., Treffert, F., (0000-0003-0390-7671) Schramm, U., (0000-0003-3926-409X) Zeil, K., (0000-0001-6200-6406) Rehwald, M., Assenbaum, S., (0000-0003-1739-0159) Bernert, C., (0000-0001-8756-181X) Curry, C. B., Gauthier, M., Glenzer, S. H., Göde, S., Schoenwaelder, C., Treffert, F., (0000-0003-0390-7671) Schramm, U., and (0000-0003-3926-409X) Zeil, K.
Abstract: Laser-plasma based ion accelerators require suitable high-repetition rate target systems that enable systematic studies at controlled plasma conditions and application-relevant particle flux. Self-refreshing, micrometer-sized cryogenic jets have proven to be an ideal target platform. Yet, operation of such systems in the harsh environmental conditions of high power laser induced plasma experiments have turned out to be challenging. Here we report on recent experiments deploying a cryogenic hydrogen jet as a source of pure proton beams generated with the PW-class ultrashort pulse laser DRACO. Damage to the jet target system during application of full energy laser shots was prevented by implementation of a mechanical chopper system interrupting the direct line of sight between the laser plasma interaction zone and the jet source.
Published: 2022

30. Ultra-short pulse laser-driven acceleration of protons to 80 MeV from density tailored cryogenic hydrogen jets

Author: (0000-0001-6200-6406) Rehwald, M., Bernert, C., (0000-0002-9859-2408) Brack, F.-E., (0000-0002-5845-000X) Cowan, T., Curry, C. B., Fiuza, F., (0000-0001-6994-2475) Garten, M., (0000-0002-6914-4083) Gaus, L., Gauthier, M., Göde, S., Göthel, I., Glenzer, S. H., (0000-0003-1943-7141) Hübl, A., Kim, J. B., (0000-0003-4861-5584) Kluge, T., (0000-0002-0638-6990) Kraft, S., (0000-0002-0275-9892) Kroll, F., (0000-0002-9556-0662) Metzkes-Ng, J., (0000-0001-7858-0007) Löser, M., (0000-0001-9236-8037) Obst-Hübl, L., (0000-0003-4962-2153) Reimold, M., (0000-0003-4400-1315) Schlenvoigt, H.-P., Schoenwaelder, C., (0000-0003-0390-7671) Schramm, U., (0000-0002-4697-3014) Siebold, M., Treffert, F., (0000-0002-3727-7017) Ziegler, T., (0000-0003-3926-409X) Zeil, K., (0000-0001-6200-6406) Rehwald, M., Bernert, C., (0000-0002-9859-2408) Brack, F.-E., (0000-0002-5845-000X) Cowan, T., Curry, C. B., Fiuza, F., (0000-0001-6994-2475) Garten, M., (0000-0002-6914-4083) Gaus, L., Gauthier, M., Göde, S., Göthel, I., Glenzer, S. H., (0000-0003-1943-7141) Hübl, A., Kim, J. B., (0000-0003-4861-5584) Kluge, T., (0000-0002-0638-6990) Kraft, S., (0000-0002-0275-9892) Kroll, F., (0000-0002-9556-0662) Metzkes-Ng, J., (0000-0001-7858-0007) Löser, M., (0000-0001-9236-8037) Obst-Hübl, L., (0000-0003-4962-2153) Reimold, M., (0000-0003-4400-1315) Schlenvoigt, H.-P., Schoenwaelder, C., (0000-0003-0390-7671) Schramm, U., (0000-0002-4697-3014) Siebold, M., Treffert, F., (0000-0002-3727-7017) Ziegler, T., and (0000-0003-3926-409X) Zeil, K.
Abstract: Laser plasma based particle accelerators have attracted great interest in fields where conventional accelerators reach limits based on size, cost or beam parameters. Designing future laser ion accelerators requires a high degree of control of the advanced acceleration schemes involved and predictive modelling capabilities. Here, we investigate the interaction of petawatt class laser pulses with a micrometer sized cryogenic hydrogen jet target. Controlled pre-expansion of the target by low intensity pre-pulses allowed for tailored density scans over more than two orders of magnitude. On-shot target characterization using two-color optical probing provided precise starting conditions for numerical simulations. For the optimal target density profile in the near critical regime proton energies of up to 80 MeV were observed which represents a two-fold increase with respect to the initial solid target case. Three-dimensional particle in cell simulations confirmed the transition between different acceleration mechanisms involved and suggested the magnetic-vortex regime to be responsible for the highest proton energies achieved.
Published: 2022

31. Laser-proton acceleration developments at DRACO-PW enabling “in-vivo” radiobiology

Author: (0000-0002-3727-7017) Ziegler, T., (0000-0003-1739-0159) Bernert, C., (0000-0002-0582-1444) Beyreuther, E., (0000-0002-9859-2408) Brack, F.-E., (0000-0002-5845-000X) Cowan, T., (0000-0001-6994-2475) Garten, M., (0000-0002-6914-4083) Gaus, L., (0000-0003-4861-5584) Kluge, T., (0000-0002-0638-6990) Kraft, S., (0000-0002-0275-9892) Kroll, F., (0000-0002-9556-0662) Metzkes-Ng, J., (0000-0003-4128-5498) Pawelke, J., (0000-0003-4962-2153) Reimold, M., (0000-0001-6200-6406) Rehwald, M., (0000-0003-4400-1315) Schlenvoigt, H.-P., (0000-0001-7332-7395) Umlandt, M. E. P., (0000-0003-0390-7671) Schramm, U., (0000-0003-3926-409X) Zeil, K., (0000-0002-3727-7017) Ziegler, T., (0000-0003-1739-0159) Bernert, C., (0000-0002-0582-1444) Beyreuther, E., (0000-0002-9859-2408) Brack, F.-E., (0000-0002-5845-000X) Cowan, T., (0000-0001-6994-2475) Garten, M., (0000-0002-6914-4083) Gaus, L., (0000-0003-4861-5584) Kluge, T., (0000-0002-0638-6990) Kraft, S., (0000-0002-0275-9892) Kroll, F., (0000-0002-9556-0662) Metzkes-Ng, J., (0000-0003-4128-5498) Pawelke, J., (0000-0003-4962-2153) Reimold, M., (0000-0001-6200-6406) Rehwald, M., (0000-0003-4400-1315) Schlenvoigt, H.-P., (0000-0001-7332-7395) Umlandt, M. E. P., (0000-0003-0390-7671) Schramm, U., and (0000-0003-3926-409X) Zeil, K.
Abstract: We report technological developments at DRACO-PW to monitor and improve laser-plasma conditions resulting in a stable particle-source >60MeV, which in combination with our transport-beamline and high-quality dosimetry enabled first dose-controlled “in-vivo” studies with laser-driven protons.
Published: 2022

32. High energy proton detection in Draco PW experiments

Author: (0000-0003-3926-409X) Zeil, K., Assenbaum, S., (0000-0003-1739-0159) Bernert, C., (0000-0002-9859-2408) Brack, F.-E., (0000-0002-5845-000X) Cowan, T., (0000-0001-6994-2475) Garten, M., (0000-0002-6914-4083) Gaus, L., Göthel, I., (0000-0003-4861-5584) Kluge, T., (0000-0002-0638-6990) Kraft, S., (0000-0002-0275-9892) Kroll, F., (0000-0002-9556-0662) Metzkes-Ng, J., (0000-0003-4962-2153) Reimold, M., (0000-0001-6200-6406) Rehwald, M., (0000-0003-4400-1315) Schlenvoigt, H.-P., (0000-0001-7332-7395) Umlandt, M. E. P., Vescovi Pinochet, M. A., (0000-0002-3727-7017) Ziegler, T., (0000-0003-0390-7671) Schramm, U., (0000-0003-3926-409X) Zeil, K., Assenbaum, S., (0000-0003-1739-0159) Bernert, C., (0000-0002-9859-2408) Brack, F.-E., (0000-0002-5845-000X) Cowan, T., (0000-0001-6994-2475) Garten, M., (0000-0002-6914-4083) Gaus, L., Göthel, I., (0000-0003-4861-5584) Kluge, T., (0000-0002-0638-6990) Kraft, S., (0000-0002-0275-9892) Kroll, F., (0000-0002-9556-0662) Metzkes-Ng, J., (0000-0003-4962-2153) Reimold, M., (0000-0001-6200-6406) Rehwald, M., (0000-0003-4400-1315) Schlenvoigt, H.-P., (0000-0001-7332-7395) Umlandt, M. E. P., Vescovi Pinochet, M. A., (0000-0002-3727-7017) Ziegler, T., and (0000-0003-0390-7671) Schramm, U.
Abstract: Exploiting the strong electromagnetic fields that can be supported by a plasma, high-power laser driven compact plasma accelerators can generate short, high-intensity pulses of high energy ions with special beam properties interesting for many application areas. The transition of laser driven ion accelerators from physics experiments to turn-key sources for these applications relies on improvement of generated beam parameters (kinetic energy, flux), as well as increased reproducibility, robustness and scalability to high repetition rate. Recent developments at the high-power laser facility DRACO-PW enabled the production of polychromatic proton beams with unprecedented stability [1] which enabled the first in vivo radiobiological study to be conducted using a laser-driven proton source [2]. Yet, the ability to achieve highest energies around or even beyond the 100 MeV frontier is matter of ongoing research, mainly addressed by exploring advanced acceleration schemes. In parallel to the testing of these schemes an important challenge is to provide convincing evidence that these very high energies could be reached at all for a significant number of particles. Occurring complications are due to the nature of the multi-species beams with typically exponentially decaying spectra and low shot statistics of laser-plasma experiments at the necessary laser pulse energy levels. The latter is in particular complicated for highly non-linear acceleration regimes with intrinsically low reproducibility. In this talk we summarize our approaches for the spatial and spectral characterization of our proton beam parameters with cut-off energies larger than 80 MeV. Key is the combination of a multitude of different methods based on different detection principles established for single shot measurements. Time-of-flight methods are discussed for energy cross-calibration of our Thomson parabola spectrometers and the use of different screen types for on-shot particle number calibration is p
Published: 2022

33. Experimental study of Relativistic High Harmonic Generation with a PW level short pulse laser system

Author: (0000-0002-2828-5373) Vescovi Pinochet, M. A., (0000-0001-7332-7395) Umlandt, M. E. P., (0000-0002-6928-2048) Assenbaum, S., Meric, T., (0000-0002-0275-9892) Kroll, F., (0000-0001-6200-6406) Rehwald, M., (0000-0002-4195-2038) Stefanikova, R., (0000-0002-4738-6436) Püschel, T., (0000-0003-0931-1350) Prencipe, I., (0000-0002-0638-6990) Kraft, S., (0000-0003-3926-409X) Zeil, K., (0000-0003-0390-7671) Schramm, U., (0000-0002-2828-5373) Vescovi Pinochet, M. A., (0000-0001-7332-7395) Umlandt, M. E. P., (0000-0002-6928-2048) Assenbaum, S., Meric, T., (0000-0002-0275-9892) Kroll, F., (0000-0001-6200-6406) Rehwald, M., (0000-0002-4195-2038) Stefanikova, R., (0000-0002-4738-6436) Püschel, T., (0000-0003-0931-1350) Prencipe, I., (0000-0002-0638-6990) Kraft, S., (0000-0003-3926-409X) Zeil, K., and (0000-0003-0390-7671) Schramm, U.
Abstract: Surface High harmonic generation (SHHG) arising from the interaction of high and ultra- high intensity lasers with solid density targets has been extensively studied during recent years. Besides being a promising source for applications on ultrafast science, the sensitivity of SHHG mechanisms with respect to changes of pump laser parameters or target pre-plasma conditions makes the harmonic spectrum a useful diagnostic to gain insight into the interaction between the laser and the target front surface where, in case of a solid density target, most of the energy absorption between laser and target takes place. In the present work, the first measurements of high harmonic spectra on the Draco PW laser system at HZDR are presented. Most measurements were done using a single plasma mirror system, achieving a contrast of 10-7 at -1ps for a 5.4x1021W/cm2, 30fs 800nm pulse. XUV spectra were measured for a wide range of different target materials (plastic, metal, glass), thicknesses; from bulk SiO2 substrates to few tens of nm foils where relativistic transparency starts to occur; as well as different laser energies (a0~7-50). The spectral range of the spectrometer (53nm to ~17nm, 15th to 47th harmonic, limited by the filtering) allowed us to measure changes in SHHG along the spectrum for different interaction conditions. These measurements were carried in parallel with proton acceleration experiments, aiming at using the harmonic generation as a gauge for the laser-plasma interaction at different interaction regimes, and to our knowledge constitute one of the first measurements of relativistic surface harmonics with a PW short pulse laser.
Published: 2022

34. Laser-proton acceleration in the near-critical regime using density tailored cryogenic hydrogen jets

Author: (0000-0001-6200-6406) Rehwald, M. and (0000-0001-6200-6406) Rehwald, M.
Abstract: Modern particle accelerators are a key component of today’s research landscape and indispensable in industry and medicine. In special application areas, the portfolio of these facilities will be expanded by laser-driven compact plasma accelerators that generate short, high-intensity pulses of ions with unique beam properties. Though intensely explored by the community, scaling the maximum beam energies of laser-driven ion accelerators to the required level is one of the most significant challenges of this field. This endeavor is inherently linked to a fundamental understanding of the underlying acceleration processes. The prospect to effciently increase the beam energy relies on the ability to control the accelerating field structures beyond the well-established acceleration from the stationary target rear side. However, manipulating the interaction in such micrometer-sized accelerators proves to be challenging due to the transient nature of the plasma fields and requires precise tuning of the temporal laser pulse shape and the volumetric density distribution of the plasma target to a level that could so far not be achieved. This thesis investigates laser-proton acceleration using a cryogenic hydrogen target that combines the capabilities of predictive three-dimensional simulation and the in-situ realtime monitoring of the density distribution in the experiment to explore the fundamental physical principles of plasma based acceleration mechanisms. The corresponding experiments were performed at the DRACO laser facility at the Helmholtz-Zentrum Dresden-Rossendorf. The key to the success of these studies was the advancement of the cryogenic target system that generates a self-replenishing pure hydrogen jet. Using a mechanical chopping device, which protects the target system from the disruptive influence originating from the high-intensity interaction, allowed, for the first time, systematic experiments with a large number of laser shots in the harsh environment of th
Published: 2022

35. Optimized laser ion acceleration at the relativistic critical density surface

Author: Göthel, I., (0000-0003-1739-0159) Bernert, C., (0000-0002-8258-3881) Bussmann, M., (0000-0001-6994-2475) Garten, M., Miethlinger, T., (0000-0001-6200-6406) Rehwald, M., (0000-0003-3926-409X) Zeil, K., (0000-0002-3727-7017) Ziegler, T., (0000-0002-5845-000X) Cowan, T., (0000-0003-0390-7671) Schramm, U., (0000-0003-4861-5584) Kluge, T., Göthel, I., (0000-0003-1739-0159) Bernert, C., (0000-0002-8258-3881) Bussmann, M., (0000-0001-6994-2475) Garten, M., Miethlinger, T., (0000-0001-6200-6406) Rehwald, M., (0000-0003-3926-409X) Zeil, K., (0000-0002-3727-7017) Ziegler, T., (0000-0002-5845-000X) Cowan, T., (0000-0003-0390-7671) Schramm, U., and (0000-0003-4861-5584) Kluge, T.
Abstract: In the effort of achieving high-energetic ion beams from the interaction of ultrashort laser pulses with a plasma, volumetric acceleration mechanisms beyond Target Normal Sheath Acceleration have gained attention. A relativisticly intense laser can turn a near critical density plasma slowly transparent, facilitating a synchronized acceleration of ions at the moving relativistic critical density front. While simulations promise extremely high ion energies in in this regime, the challenge resides in the realization of a synchronized movement of the ultra-relativistic laser pulse ($a_0\gtrsim 30$) driven reflective relativistic electron front and the fastest ions, which imposes a narrow parameter range on the laser and plasma parameters. We present an analytic model for the relevant processes, confirmed by a broad parameter simulation study in 1D- and 3D-geometry. By tayloring the pulse length and plasma density profile at the front side, we can optimize the proton acceleration performance and extend the regions in parameter space of efficient ion acceleration at the relativistic relativistic density surface.
Published: 2022

36. Off-harmonic optical probing of high-intensity laser-plasma expansion dynamics in solid-density hydrogen jets

Author: (0000-0003-1739-0159) Bernert, C., (0000-0002-6928-2048) Assenbaum, S., (0000-0002-9859-2408) Brack, F.-E., (0000-0002-5845-000X) Cowan, T., Curry, C. B., (0000-0001-6994-2475) Garten, M., (0000-0002-6914-4083) Gaus, L., Gauthier, M., GöDe, S., Göthel, I., Glenzer, S. H., (0000-0003-4861-5584) Kluge, T., (0000-0002-0638-6990) Kraft, S., (0000-0002-0275-9892) Kroll, F., (0000-0002-8145-5837) Kuntzsch, M., (0000-0002-9556-0662) Metzkes-Ng, J., (0000-0001-7858-0007) Löser, M., (0000-0001-9236-8037) Obst-Hübl, L., (0000-0001-6200-6406) Rehwald, M., (0000-0003-4400-1315) Schlenvoigt, H.-P., Schoenwaelder, C., (0000-0003-0390-7671) Schramm, U., (0000-0002-4697-3014) Siebold, M., Treffert, F., (0000-0002-3727-7017) Ziegler, T., (0000-0003-3926-409X) Zeil, K., (0000-0003-1739-0159) Bernert, C., (0000-0002-6928-2048) Assenbaum, S., (0000-0002-9859-2408) Brack, F.-E., (0000-0002-5845-000X) Cowan, T., Curry, C. B., (0000-0001-6994-2475) Garten, M., (0000-0002-6914-4083) Gaus, L., Gauthier, M., GöDe, S., Göthel, I., Glenzer, S. H., (0000-0003-4861-5584) Kluge, T., (0000-0002-0638-6990) Kraft, S., (0000-0002-0275-9892) Kroll, F., (0000-0002-8145-5837) Kuntzsch, M., (0000-0002-9556-0662) Metzkes-Ng, J., (0000-0001-7858-0007) Löser, M., (0000-0001-9236-8037) Obst-Hübl, L., (0000-0001-6200-6406) Rehwald, M., (0000-0003-4400-1315) Schlenvoigt, H.-P., Schoenwaelder, C., (0000-0003-0390-7671) Schramm, U., (0000-0002-4697-3014) Siebold, M., Treffert, F., (0000-0002-3727-7017) Ziegler, T., and (0000-0003-3926-409X) Zeil, K.
Abstract: Due to the non-linear nature of relativistic laser induced plasma processes, the development of laser-plasma accelerators requires precise numerical modeling. Especially high intensity laser-solid interactions are sensitive to the temporal laser rising edge and the predictive capability of simulations suffers from incomplete information on the plasma state at the onset of the relativistic interaction. Experimental diagnostics utilizing ultra-fast optical backlighters can help to ease this challenge by providing temporally resolved inside into the plasma density evolution. We present the successful implementation of an off-harmonic optical probe laser setup to investigate the interaction of a high-intensity laser at 5.4E21 W / cm^2 peak intensity with a solid-density cylindrical cryogenic hydrogen jet target of 5 um diameter as a target test bed. The temporal synchronization of pump and probe laser, spectral filtering and spectrally resolved data of the parasitic plasma self-emission are discussed. The probing technique mitigates detector saturation by self-emission and allowed to record a temporal scan of shadowgraphy data revealing details of the target ionization and expansion dynamics that were so far not accessible for the given laser intensity. Plasma expansion speeds of up to (2.3+-0.4)E7 m / s followed by full target transparency at 1.4 ps after the high intensity laser peak are observed. A three dimensional particle-in-cell simulation initiated with the diagnosed target pre-expansion at -0.2 ps and post processed by ray tracing simulations supports the experimental observations and demonstrates the capability of time resolved optical diagnostics to provide quantitative input and feedback to the numerical treatment within the time frame of the relativistic laser-plasma interaction.
Published: 2022

37. Tumor irradiation in mice with a laser-accelerated proton beam

Author: (0000-0002-0275-9892) Kroll, F., (0000-0002-9859-2408) Brack, F.-E., (0000-0003-1739-0159) Bernert, C., (0000-0002-1919-8585) Bock, S., Bodenstein, E., Brüchner, K., (0000-0002-5845-000X) Cowan, T., (0000-0002-6914-4083) Gaus, L., Gebhardt, R., Helbig, U., Karsch, L., (0000-0003-4861-5584) Kluge, T., (0000-0002-0638-6990) Kraft, S., (0000-0003-1776-9556) Krause, M., Leßmann, E., (0000-0002-5248-0910) Masood, U., Meister, S., (0000-0002-9556-0662) Metzkes-Ng, J., Nossula, A., (0000-0003-4128-5498) Pawelke, J., (0000-0002-1610-1493) Pietzsch, J., (0000-0002-4738-6436) Püschel, T., (0000-0003-4962-2153) Reimold, M., (0000-0001-6200-6406) Rehwald, M., (0000-0003-4261-4214) Richter, C., (0000-0003-4400-1315) Schlenvoigt, H.-P., (0000-0003-0390-7671) Schramm, U., (0000-0001-7332-7395) Umlandt, M. E. P., (0000-0002-3727-7017) Ziegler, T., (0000-0003-3926-409X) Zeil, K., (0000-0002-0582-1444) Beyreuther, E., (0000-0002-0275-9892) Kroll, F., (0000-0002-9859-2408) Brack, F.-E., (0000-0003-1739-0159) Bernert, C., (0000-0002-1919-8585) Bock, S., Bodenstein, E., Brüchner, K., (0000-0002-5845-000X) Cowan, T., (0000-0002-6914-4083) Gaus, L., Gebhardt, R., Helbig, U., Karsch, L., (0000-0003-4861-5584) Kluge, T., (0000-0002-0638-6990) Kraft, S., (0000-0003-1776-9556) Krause, M., Leßmann, E., (0000-0002-5248-0910) Masood, U., Meister, S., (0000-0002-9556-0662) Metzkes-Ng, J., Nossula, A., (0000-0003-4128-5498) Pawelke, J., (0000-0002-1610-1493) Pietzsch, J., (0000-0002-4738-6436) Püschel, T., (0000-0003-4962-2153) Reimold, M., (0000-0001-6200-6406) Rehwald, M., (0000-0003-4261-4214) Richter, C., (0000-0003-4400-1315) Schlenvoigt, H.-P., (0000-0003-0390-7671) Schramm, U., (0000-0001-7332-7395) Umlandt, M. E. P., (0000-0002-3727-7017) Ziegler, T., (0000-0003-3926-409X) Zeil, K., and (0000-0002-0582-1444) Beyreuther, E.
Abstract: Recent oncological studies identified beneficial properties of radiation applied at ultra-high dose rates several orders of magnitude higher than the clinical standard of the order of Gy/min. Sources capable of providing these ultra-high dose rates are under investigation. Here, we show that a stable, compact laser-driven proton source with energies greater than 60 MeV enables radiobiological in vivo studies. We performed a pilot irradiation study on human tumors in a mouse model, showing the concerted preparation of mice and laser accelerator, the dose-controlled, tumor-conform irradiation using a laser-driven as well as a clinical reference proton source, and the radiobiological evaluation of irradiated and unirradiated mice for radiation-induced tumor growth delay. The prescribed homogeneous dose of 4 Gy was precisely delivered at the laser-driven source. The results demonstrate a complete laser-driven proton research platform for diverse user-specific small animal models, able to deliver tunable single-shot doses up to around 20 Gy to millimeter-scale volumes on nanosecond time scales, equivalent to around 1E9 Gy/s, spatially homogenized and tailored to the sample. The platform provides a unique infrastructure for translational research with protons at ultra-high dose rate.
Published: 2022

38. Laser-proton acceleration in the near-critical regime using density tailored cryogenic hydrogen jets

Author: (0000-0001-6200-6406) Rehwald, M. and (0000-0001-6200-6406) Rehwald, M.
Abstract: Modern particle accelerators are a key component of today’s research landscape and indispensable in industry and medicine. In special application areas, the portfolio of these facilities will be expanded by laser-driven compact plasma accelerators that generate short, high-intensity pulses of ions with unique beam properties. Though intensely explored by the community, scaling the maximum beam energies of laser-driven ion accelerators to the required level is one of the most significant challenges of this field. This endeavor is inherently linked to a fundamental understanding of the underlying acceleration processes. The prospect to effciently increase the beam energy relies on the ability to control the accelerating field structures beyond the well-established acceleration from the stationary target rear side. However, manipulating the interaction in such micrometer-sized accelerators proves to be challenging due to the transient nature of the plasma fields and requires precise tuning of the temporal laser pulse shape and the volumetric density distribution of the plasma target to a level that could so far not be achieved. This thesis investigates laser-proton acceleration using a cryogenic hydrogen target that combines the capabilities of predictive three-dimensional simulation and the in-situ realtime monitoring of the density distribution in the experiment to explore the fundamental physical principles of plasma based acceleration mechanisms. The corresponding experiments were performed at the DRACO laser facility at the Helmholtz-Zentrum Dresden-Rossendorf. The key to the success of these studies was the advancement of the cryogenic target system that generates a self-replenishing pure hydrogen jet. Using a mechanical chopping device, which protects the target system from the disruptive influence originating from the high-intensity interaction, allowed, for the first time, systematic experiments with a large number of laser shots in the harsh environment of th
Published: 2022

39. Towards High-Repetition Rate Petawatt Laser Experiments with Cryogenic Jets Using a Mechanical Chopper System

Author: (0000-0001-6200-6406) Rehwald, M., (0000-0002-6928-2048) Assenbaum, S., (0000-0003-1739-0159) Bernert, C., (0000-0001-8756-181X) Curry, C. B., Gauthier, M., Glenzer, S. H., Göde, S., Schoenwaelder, C., Treffert, F., (0000-0003-0390-7671) Schramm, U., (0000-0003-3926-409X) Zeil, K., (0000-0001-6200-6406) Rehwald, M., (0000-0002-6928-2048) Assenbaum, S., (0000-0003-1739-0159) Bernert, C., (0000-0001-8756-181X) Curry, C. B., Gauthier, M., Glenzer, S. H., Göde, S., Schoenwaelder, C., Treffert, F., (0000-0003-0390-7671) Schramm, U., and (0000-0003-3926-409X) Zeil, K.
Abstract: Laser-plasma based ion accelerators require suitable high-repetition rate target systems that enable systematic studies at controlled plasma conditions and application-relevant particle flux. Self-refreshing, micrometer-sized cryogenic jets have proven to be an ideal target platform. Yet, operation of such systems in the harsh environmental conditions of high power laser induced plasma experiments have turned out to be challenging. Here we report on recent experiments deploying a cryogenic hydrogen jet as a source of pure proton beams generated with the PW-class ultrashort pulse laser DRACO. Damage to the jet target system during application of full energy laser shots was prevented by implementation of a mechanical chopper system interrupting the direct line of sight between the laser plasma interaction zone and the jet source.
Published: 2022

40. Combined Phase Contrast Imaging and Small-Angle X-Ray Scattering Diagnostic of Relativistic Plasmas at the High Energy Density Instrument at European XFEL

Author: (0000-0002-7671-0901) Laso García, A., Arefiev, A., Kemp, A., Allen, C. H., Bähtz, C., Nagler, B., Palmer, C. A. J., Murphy, C. D., Spindloe, C., Brown, C. R. D., Neely, D., (0000-0002-6350-4180) Kraus, D., Marley, E., Hartouni, E. P., Fiuza, F., Grim, G. P., Cochran, G. E., (0000-0003-4400-1315) Schlenvoigt, H.-P., (0000-0003-0931-1350) Prencipe, I., Williams, J., Green, J., Eggert, J. H., (0000-0003-3926-409X) Zeil, K., Lancaster, K. L., Divol, L., (0000-0002-6914-4083) Gaus, L., (0000-0003-1184-2097) Huang, L., Schoelmerich, M., (0000-0001-6200-6406) Rehwald, M., Oliver, M., Rödel, M., Macdonald, M., (0000-0002-7162-7500) Smid, M., Makita, M., Nakatsutsumi, M., (0000-0001-6748-0422) Humphries, O. S., Neumayer, P. B., Mabey, P., Shepherd, R. L., Gray, R., Wilks, S. C., Le Pape, S., Kerr, S. M., Glenzer, S. H., Funk, S., Gales, S. G., (0000-0002-5845-000X) Cowan, T., White, T. G., (0000-0003-4861-5584) Kluge, T., Doeppner, T., (0000-0001-7986-3631) Toncian, T., Zastrau, U., (0000-0003-0390-7671) Schramm, U., Ping, Y., He, Z., Höppner, H., Pelka, A., (0000-0002-7671-0901) Laso García, A., Arefiev, A., Kemp, A., Allen, C. H., Bähtz, C., Nagler, B., Palmer, C. A. J., Murphy, C. D., Spindloe, C., Brown, C. R. D., Neely, D., (0000-0002-6350-4180) Kraus, D., Marley, E., Hartouni, E. P., Fiuza, F., Grim, G. P., Cochran, G. E., (0000-0003-4400-1315) Schlenvoigt, H.-P., (0000-0003-0931-1350) Prencipe, I., Williams, J., Green, J., Eggert, J. H., (0000-0003-3926-409X) Zeil, K., Lancaster, K. L., Divol, L., (0000-0002-6914-4083) Gaus, L., (0000-0003-1184-2097) Huang, L., Schoelmerich, M., (0000-0001-6200-6406) Rehwald, M., Oliver, M., Rödel, M., Macdonald, M., (0000-0002-7162-7500) Smid, M., Makita, M., Nakatsutsumi, M., (0000-0001-6748-0422) Humphries, O. S., Neumayer, P. B., Mabey, P., Shepherd, R. L., Gray, R., Wilks, S. C., Le Pape, S., Kerr, S. M., Glenzer, S. H., Funk, S., Gales, S. G., (0000-0002-5845-000X) Cowan, T., White, T. G., (0000-0003-4861-5584) Kluge, T., Doeppner, T., (0000-0001-7986-3631) Toncian, T., Zastrau, U., (0000-0003-0390-7671) Schramm, U., Ping, Y., He, Z., Höppner, H., and Pelka, A.
Abstract: The High Energy Density (HED) instrument at the European XFEL provides a platform to study hot and warm dense matter. The Helmholtz International Beamline for Extreme Fields (HiBEF) is a User Consortium supplying HED with two laser systems (the high-intensity ReLaX laser, by Amplitude Technologies, and the high-energy Dipole-100X laser, by STFC), Diamond Anvil Cells setup and high-pulsed magnetic fields. These tools in combination with the XFEL beam enable the investigation of relativistic laser plasmas, strong-field QED phenomena, high-pressure astro- and planetary physics as well as magnetic phenomena in condensed matter. The successful commissioning of the ultra-short pulse high-intensity ReLaX laser, provides new unique opportunities in the plasma and high-field physics fields [1]. ReLaX is a double CPA Ti:Sa laser capable of delivering up to 300 TW pulses on target. In the first commissioning phase, 100 TW pulses were used, reaching intensities up to 1020 W/cm2. Small-Angle X-Ray Scattering (SAXS) without the need of a beamstop was first commissioned at HED in September 2019. Two highly annealed pyrolytic graphite (HAPG) crystals were used to reflect the SAXS photons onto a detector while allowing the main XFEL beam to go through [2]. In April and May 2021, Small Angle X-Ray Scattering and Phase Contrast Imaging (PCI) were simultaneously demonstrated in pump-probe experiments at HED in a community experiment involving 15 institutions from all over the world. In this talk we will present the preliminary results of this community experiment probing ultrafast phenomena in a wide array of target configurations: hole boring in wires, shockwave generation in CH blocks, buried heating of a wire inside a CH medium, foam ionization and collective effects in heated foils. [1] A. Laso Garcia, H. Hoeppner, A. Pelka et al., “ReLaX: the HiBEF high-intensity short-pulse laser driver for relativistic laser-matter interaction and strong-field science at the HED instrument at Eu
Published: 2022

41. Optimizing laser plasma acceleration performance for proton beams beyond the 100 MeV frontier

Author: (0000-0002-3727-7017) Ziegler, T., (0000-0002-6928-2048) Assenbaum, S., (0000-0003-1739-0159) Bernert, C., (0000-0002-9859-2408) Brack, F.-E., (0000-0002-5845-000X) Cowan, T., Dover, N. P., (0000-0001-6994-2475) Garten, M., (0000-0002-6914-4083) Gaus, L., Göthel, I., Kiriyama, H., (0000-0003-4861-5584) Kluge, T., Kon, A., (0000-0002-0638-6990) Kraft, S., (0000-0002-0275-9892) Kroll, F., (0000-0002-9556-0662) Metzkes-Ng, J., Nishuichi, M., (0000-0003-4962-2153) Reimold, M., (0000-0001-6200-6406) Rehwald, M., (0000-0003-4400-1315) Schlenvoigt, H.-P., (0000-0001-7332-7395) Umlandt, M. E. P., (0000-0003-0390-7671) Schramm, U., (0000-0002-2828-5373) Vescovi Pinochet, M. A., (0000-0003-3926-409X) Zeil, K., (0000-0002-3727-7017) Ziegler, T., (0000-0002-6928-2048) Assenbaum, S., (0000-0003-1739-0159) Bernert, C., (0000-0002-9859-2408) Brack, F.-E., (0000-0002-5845-000X) Cowan, T., Dover, N. P., (0000-0001-6994-2475) Garten, M., (0000-0002-6914-4083) Gaus, L., Göthel, I., Kiriyama, H., (0000-0003-4861-5584) Kluge, T., Kon, A., (0000-0002-0638-6990) Kraft, S., (0000-0002-0275-9892) Kroll, F., (0000-0002-9556-0662) Metzkes-Ng, J., Nishuichi, M., (0000-0003-4962-2153) Reimold, M., (0000-0001-6200-6406) Rehwald, M., (0000-0003-4400-1315) Schlenvoigt, H.-P., (0000-0001-7332-7395) Umlandt, M. E. P., (0000-0003-0390-7671) Schramm, U., (0000-0002-2828-5373) Vescovi Pinochet, M. A., and (0000-0003-3926-409X) Zeil, K.
Abstract: Exploiting the strong electromagnetic fields that can be supported by a laser driven compact plasma accelerator enables generation of short, high-intensity pulses of high energy ions with special beam properties. The maturation of such laser driven ion accelerators from physics experiments to turn-key sources for applications will rely on breakthroughs in both, generated beam parameters (kinetic energy, flux), as well as increased scrutiny on reproducibility, robustness, and scalability to high repetition rate. Recent developments at the high-power laser facility DRACO-PW enabled the production of polychromatic proton beams with unprecedented stability [1]. This facilitated the first in vivo radiobiological study using a laser-driven proton source [2]. For many related advanced applications, the ability to generate proton beams with energies beyond the 100 MeV frontier at a repetition rate and in a controllable way is essential and the subject of ongoing research. Latest experimental studies concentrated on pre-expanded plastic foil target undergoing relativistically induced transparency using linearly polarized laser pulses with peak intensities beyond 1021 W/cm2. A complex suite of particle and optical diagnostics allowed characterization of spatial and spectral proton beam parameters and the stability of this regime for best acceleration performance exceeding 100 MeV cut-off energies. Combined hydrodynamic and 3D particle-in-cell simulations helped to identify the most promising target parameter range matched to the carefully measured prevailing laser contrast conditions.
Published: 2022

42. Commissioning and First User Experiments with ReLaX and XFEL Beam

Author: (0000-0002-7671-0901) Laso García, A., Arefiev, A., Kemp, A., Allen, C. H., Bähtz, C., Nagler, B., Palmer, C. A. J., Murphy, C. D., Spindloe, C., Brown, C. R. D., Neely, D., (0000-0002-6350-4180) Kraus, D., Marley, E., Hartouni, E. P., Fiuza, F., Grim, G. P., Cochran, G. E., (0000-0003-4400-1315) Schlenvoigt, H.-P., (0000-0003-0931-1350) Prencipe, I., Williams, J., Green, J., Eggert, J. H., (0000-0003-3926-409X) Zeil, K., Lancaster, K. L., Divol, L., (0000-0002-6914-4083) Gaus, L., (0000-0003-1184-2097) Huang, L., Schoelmerich, M., (0000-0001-6200-6406) Rehwald, M., Oliver, M., Rödel, M., Macdonald, M., (0000-0002-7162-7500) Smid, M., Makita, M., Nakatsutsumi, M., (0000-0001-6748-0422) Humphries, O. S., Neumayer, P. B., Mabey, P., Shepherd, R. L., Gray, R., Wilks, S. C., Le Pape, S., Kerr, S. M., Glenzer, S. H., Funk, S., Gales, S. G., (0000-0002-5845-000X) Cowan, T., White, T. G., (0000-0003-4861-5584) Kluge, T., Doeppner, T., (0000-0001-7986-3631) Toncian, T., Zastrau, U., (0000-0003-0390-7671) Schramm, U., Ping, Y., He, Z., Höppner, H., Pelka, A., (0000-0002-7671-0901) Laso García, A., Arefiev, A., Kemp, A., Allen, C. H., Bähtz, C., Nagler, B., Palmer, C. A. J., Murphy, C. D., Spindloe, C., Brown, C. R. D., Neely, D., (0000-0002-6350-4180) Kraus, D., Marley, E., Hartouni, E. P., Fiuza, F., Grim, G. P., Cochran, G. E., (0000-0003-4400-1315) Schlenvoigt, H.-P., (0000-0003-0931-1350) Prencipe, I., Williams, J., Green, J., Eggert, J. H., (0000-0003-3926-409X) Zeil, K., Lancaster, K. L., Divol, L., (0000-0002-6914-4083) Gaus, L., (0000-0003-1184-2097) Huang, L., Schoelmerich, M., (0000-0001-6200-6406) Rehwald, M., Oliver, M., Rödel, M., Macdonald, M., (0000-0002-7162-7500) Smid, M., Makita, M., Nakatsutsumi, M., (0000-0001-6748-0422) Humphries, O. S., Neumayer, P. B., Mabey, P., Shepherd, R. L., Gray, R., Wilks, S. C., Le Pape, S., Kerr, S. M., Glenzer, S. H., Funk, S., Gales, S. G., (0000-0002-5845-000X) Cowan, T., White, T. G., (0000-0003-4861-5584) Kluge, T., Doeppner, T., (0000-0001-7986-3631) Toncian, T., Zastrau, U., (0000-0003-0390-7671) Schramm, U., Ping, Y., He, Z., Höppner, H., and Pelka, A.
Abstract: In this presentation we provide an overview of the commissioning and first user experiment of ReLaX in combination with the XFEL beam. We will introduce the setup and laser parameters. We will show the established standard setup combining small-angle x-ray scattering (SAXS), phase-contrast imaging (PCI) and spectroscopy techniques. Finally we will show examples of the data obtained in the interaction of the ReLaX laser with targets of interested for the short-pulse laser community.
Published: 2022

43. Laser-plasma based proton accelerators for small animal pre-clinical radiation research

Author: (0000-0002-0275-9892) Kroll, F., (0000-0002-9859-2408) Brack, F.-E., (0000-0003-1739-0159) Bernert, C., (0000-0002-1919-8585) Bock, S., (0000-0001-8205-8422) Bodenstein, E., Brüchner, K., (0000-0002-5845-000X) Cowan, T., (0000-0002-6914-4083) Gaus, L., Gebhardt, R., Helbig, U., Karsch, L., (0000-0003-4861-5584) Kluge, T., (0000-0002-0638-6990) Kraft, S., (0000-0003-1776-9556) Krause, M., Leßmann, E., Masood, U., Meister, S., Nossula, A., (0000-0003-4128-5498) Pawelke, J., (0000-0002-1610-1493) Pietzsch, J., (0000-0002-4738-6436) Püschel, T., (0000-0003-4962-2153) Reimold, M., (0000-0001-6200-6406) Rehwald, M., (0000-0003-4261-4214) Richter, C., (0000-0003-4400-1315) Schlenvoigt, H.-P., (0000-0003-0390-7671) Schramm, U., (0000-0001-7332-7395) Umlandt, M. E. P., (0000-0002-3727-7017) Ziegler, T., (0000-0003-3926-409X) Zeil, K., (0000-0002-0582-1444) Beyreuther, E., (0000-0002-9556-0662) Metzkes-Ng, J., (0000-0002-0275-9892) Kroll, F., (0000-0002-9859-2408) Brack, F.-E., (0000-0003-1739-0159) Bernert, C., (0000-0002-1919-8585) Bock, S., (0000-0001-8205-8422) Bodenstein, E., Brüchner, K., (0000-0002-5845-000X) Cowan, T., (0000-0002-6914-4083) Gaus, L., Gebhardt, R., Helbig, U., Karsch, L., (0000-0003-4861-5584) Kluge, T., (0000-0002-0638-6990) Kraft, S., (0000-0003-1776-9556) Krause, M., Leßmann, E., Masood, U., Meister, S., Nossula, A., (0000-0003-4128-5498) Pawelke, J., (0000-0002-1610-1493) Pietzsch, J., (0000-0002-4738-6436) Püschel, T., (0000-0003-4962-2153) Reimold, M., (0000-0001-6200-6406) Rehwald, M., (0000-0003-4261-4214) Richter, C., (0000-0003-4400-1315) Schlenvoigt, H.-P., (0000-0003-0390-7671) Schramm, U., (0000-0001-7332-7395) Umlandt, M. E. P., (0000-0002-3727-7017) Ziegler, T., (0000-0003-3926-409X) Zeil, K., (0000-0002-0582-1444) Beyreuther, E., and (0000-0002-9556-0662) Metzkes-Ng, J.
Abstract: Laser-plasma based proton accelerators as a novel accelerator technology have matured to a level at which laboratory-scale setups for the emerging topic of image-guided precision small animal irradiation studies come into reach [Bra2019]. Providing a high proton energy bandwidth [Sch2016] which is filtered in a tunable pulsed magnet beam transport, these accelerators enable flexibility in terms of scattering-free irradiation field formation [Mas2014, Mas2015]. Regarding temporal dose delivery, with single pulse doses reaching the Gy level at unprecedented peak dose rates of up to 1012 Gy/s [Sch2016], laser-plasma based proton accelerator setups can give access to the dose rate regime of FLASH [Fav2014, Voz2019]. The realization of a full-scale setup for image-guided precision radiobiological studies for small animals focusing on dose rate dependent effects is currently prepared at the PENELOPE laser-plasma based proton accelerator at HZDR and will be presented with a focus on the technological requirements and solutions for dose delivery at laser-plasma based sources. This development relies on our experience in performing dose-controlled radiobiological in vitro studies [Kra2010, Zei2013] and first in vivo irradiation experiments at the DRACO laser-plasma based proton accelerator at HZDR, where we have established a pulsed solenoid beamline for 3D irradiation field formation, yielding a (5 mm)³ homogeneous volumetric dose distribution at a Gy single pulse dose level [8]. [Bra2019] F.-E. Brack, F. Kroll, L. Gaus, C. Bernert, E. Beyreuther, T. E. Cowan, L. Karsch, S. D. Kraft, L. A. Kunz-Schughart, E. Lessmann, J. Metzkes-Ng, L. Obst-Hübl, J. Pawelke, M. Rehwald, H.-P. Schlenvoigt, U. Schramm, M. Sobiella, E. R. Szabó, T. Ziegler, K. Zeil, Spectral and spatial shaping of laser-driven proton beams using a pulsed high-field magnet beamline. arXiv:1910.08430 (2019) [Sch2016] J. Schreiber, P. Bolton, K. Parodi, “Hands-on” laser-driven ion acceleration: A primer for laser
Published: 2022

44. High energy proton detection in Draco PW experiments

Author: (0000-0003-3926-409X) Zeil, K., (0000-0002-6928-2048) Assenbaum, S., (0000-0003-1739-0159) Bernert, C., (0000-0002-9859-2408) Brack, F.-E., (0000-0002-5845-000X) Cowan, T., (0000-0001-6994-2475) Garten, M., (0000-0002-6914-4083) Gaus, L., Göthel, I., (0000-0003-4861-5584) Kluge, T., (0000-0002-0638-6990) Kraft, S., (0000-0002-0275-9892) Kroll, F., (0000-0002-9556-0662) Metzkes-Ng, J., (0000-0003-4962-2153) Reimold, M., (0000-0001-6200-6406) Rehwald, M., (0000-0003-4400-1315) Schlenvoigt, H.-P., (0000-0001-7332-7395) Umlandt, M. E. P., (0000-0002-2828-5373) Vescovi Pinochet, M. A., (0000-0002-3727-7017) Ziegler, T., (0000-0003-0390-7671) Schramm, U., (0000-0003-3926-409X) Zeil, K., (0000-0002-6928-2048) Assenbaum, S., (0000-0003-1739-0159) Bernert, C., (0000-0002-9859-2408) Brack, F.-E., (0000-0002-5845-000X) Cowan, T., (0000-0001-6994-2475) Garten, M., (0000-0002-6914-4083) Gaus, L., Göthel, I., (0000-0003-4861-5584) Kluge, T., (0000-0002-0638-6990) Kraft, S., (0000-0002-0275-9892) Kroll, F., (0000-0002-9556-0662) Metzkes-Ng, J., (0000-0003-4962-2153) Reimold, M., (0000-0001-6200-6406) Rehwald, M., (0000-0003-4400-1315) Schlenvoigt, H.-P., (0000-0001-7332-7395) Umlandt, M. E. P., (0000-0002-2828-5373) Vescovi Pinochet, M. A., (0000-0002-3727-7017) Ziegler, T., and (0000-0003-0390-7671) Schramm, U.
Abstract: Exploiting the strong electromagnetic fields that can be supported by a plasma, high-power laser driven compact plasma accelerators can generate short, high-intensity pulses of high energy ions with special beam properties interesting for many application areas. The transition of laser driven ion accelerators from physics experiments to turn-key sources for these applications relies on improvement of generated beam parameters (kinetic energy, flux), as well as increased reproducibility, robustness and scalability to high repetition rate. Recent developments at the high-power laser facility DRACO-PW enabled the production of polychromatic proton beams with unprecedented stability [1] which enabled the first in vivo radiobiological study to be conducted using a laser-driven proton source [2]. Yet, the ability to achieve highest energies around or even beyond the 100 MeV frontier is matter of ongoing research, mainly addressed by exploring advanced acceleration schemes. In parallel to the testing of these schemes an important challenge is to provide convincing evidence that these very high energies could be reached at all for a significant number of particles. Occurring complications are due to the nature of the multi-species beams with typically exponentially decaying spectra and low shot statistics of laser-plasma experiments at the necessary laser pulse energy levels. The latter is in particular complicated for highly non-linear acceleration regimes with intrinsically low reproducibility. In this talk we summarize our approaches for the spatial and spectral characterization of our proton beam parameters with cut-off energies larger than 80 MeV. Key is the combination of a multitude of different methods based on different detection principles established for single shot measurements. Time-of-flight methods are discussed for energy cross-calibration of our Thomson parabola spectrometers and the use of different screen types for on-shot particle number calibration is p
Published: 2022

45. Experimental study of Relativistic High Harmonic Generation with a PW level short pulse laser system

Author: (0000-0002-2828-5373) Vescovi Pinochet, M. A., (0000-0001-7332-7395) Umlandt, M. E. P., (0000-0002-6928-2048) Assenbaum, S., Meric, T., (0000-0002-0275-9892) Kroll, F., (0000-0001-6200-6406) Rehwald, M., (0000-0002-4195-2038) Stefanikova, R., (0000-0002-4738-6436) Püschel, T., (0000-0003-0931-1350) Prencipe, I., (0000-0002-0638-6990) Kraft, S., (0000-0003-3926-409X) Zeil, K., (0000-0003-0390-7671) Schramm, U., (0000-0002-2828-5373) Vescovi Pinochet, M. A., (0000-0001-7332-7395) Umlandt, M. E. P., (0000-0002-6928-2048) Assenbaum, S., Meric, T., (0000-0002-0275-9892) Kroll, F., (0000-0001-6200-6406) Rehwald, M., (0000-0002-4195-2038) Stefanikova, R., (0000-0002-4738-6436) Püschel, T., (0000-0003-0931-1350) Prencipe, I., (0000-0002-0638-6990) Kraft, S., (0000-0003-3926-409X) Zeil, K., and (0000-0003-0390-7671) Schramm, U.
Abstract: Surface High harmonic generation (SHHG) arising from the interaction of high and ultra- high intensity lasers with solid density targets has been extensively studied during recent years. Besides being a promising source for applications on ultrafast science, the sensitivity of SHHG mechanisms with respect to changes of pump laser parameters or target pre-plasma conditions makes the harmonic spectrum a useful diagnostic to gain insight into the interaction between the laser and the target front surface where, in case of a solid density target, most of the energy absorption between laser and target takes place. In the present work, the first measurements of high harmonic spectra on the Draco PW laser system at HZDR are presented. Most measurements were done using a single plasma mirror system, achieving a contrast of 10-7 at -1ps for a 5.4x1021W/cm2, 30fs 800nm pulse. XUV spectra were measured for a wide range of different target materials (plastic, metal, glass), thicknesses; from bulk SiO2 substrates to few tens of nm foils where relativistic transparency starts to occur; as well as different laser energies (a0~7-50). The spectral range of the spectrometer (53nm to ~17nm, 15th to 47th harmonic, limited by the filtering) allowed us to measure changes in SHHG along the spectrum for different interaction conditions. These measurements were carried in parallel with proton acceleration experiments, aiming at using the harmonic generation as a gauge for the laser-plasma interaction at different interaction regimes, and to our knowledge constitute one of the first measurements of relativistic surface harmonics with a PW short pulse laser.
Published: 2022

46. Tumor irradiation in mice with a laser-accelerated proton beam

Author: (0000-0002-0275-9892) Kroll, F., (0000-0002-9859-2408) Brack, F.-E., (0000-0003-1739-0159) Bernert, C., (0000-0002-1919-8585) Bock, S., Bodenstein, E., Brüchner, K., (0000-0002-5845-000X) Cowan, T., (0000-0002-6914-4083) Gaus, L., Gebhardt, R., Helbig, U., Karsch, L., (0000-0003-4861-5584) Kluge, T., (0000-0002-0638-6990) Kraft, S., (0000-0003-1776-9556) Krause, M., Leßmann, E., (0000-0002-5248-0910) Masood, U., Meister, S., (0000-0002-9556-0662) Metzkes-Ng, J., Nossula, A., (0000-0003-4128-5498) Pawelke, J., (0000-0002-1610-1493) Pietzsch, J., (0000-0002-4738-6436) Püschel, T., (0000-0003-4962-2153) Reimold, M., (0000-0001-6200-6406) Rehwald, M., (0000-0003-4261-4214) Richter, C., (0000-0003-4400-1315) Schlenvoigt, H.-P., (0000-0003-0390-7671) Schramm, U., (0000-0001-7332-7395) Umlandt, M. E. P., (0000-0002-3727-7017) Ziegler, T., (0000-0003-3926-409X) Zeil, K., (0000-0002-0582-1444) Beyreuther, E., (0000-0002-0275-9892) Kroll, F., (0000-0002-9859-2408) Brack, F.-E., (0000-0003-1739-0159) Bernert, C., (0000-0002-1919-8585) Bock, S., Bodenstein, E., Brüchner, K., (0000-0002-5845-000X) Cowan, T., (0000-0002-6914-4083) Gaus, L., Gebhardt, R., Helbig, U., Karsch, L., (0000-0003-4861-5584) Kluge, T., (0000-0002-0638-6990) Kraft, S., (0000-0003-1776-9556) Krause, M., Leßmann, E., (0000-0002-5248-0910) Masood, U., Meister, S., (0000-0002-9556-0662) Metzkes-Ng, J., Nossula, A., (0000-0003-4128-5498) Pawelke, J., (0000-0002-1610-1493) Pietzsch, J., (0000-0002-4738-6436) Püschel, T., (0000-0003-4962-2153) Reimold, M., (0000-0001-6200-6406) Rehwald, M., (0000-0003-4261-4214) Richter, C., (0000-0003-4400-1315) Schlenvoigt, H.-P., (0000-0003-0390-7671) Schramm, U., (0000-0001-7332-7395) Umlandt, M. E. P., (0000-0002-3727-7017) Ziegler, T., (0000-0003-3926-409X) Zeil, K., and (0000-0002-0582-1444) Beyreuther, E.
Abstract: Recent oncological studies identified beneficial properties of radiation applied at ultra-high dose rates several orders of magnitude higher than the clinical standard of the order of Gy/min. Sources capable of providing these ultra-high dose rates are under investigation. Here, we show that a stable, compact laser-driven proton source with energies greater than 60 MeV enables radiobiological in vivo studies. We performed a pilot irradiation study on human tumors in a mouse model, showing the concerted preparation of mice and laser accelerator, the dose-controlled, tumor-conform irradiation using a laser-driven as well as a clinical reference proton source, and the radiobiological evaluation of irradiated and unirradiated mice for radiation-induced tumor growth delay. The prescribed homogeneous dose of 4 Gy was precisely delivered at the laser-driven source. The results demonstrate a complete laser-driven proton research platform for diverse user-specific small animal models, able to deliver tunable single-shot doses up to around 20 Gy to millimeter-scale volumes on nanosecond time scales, equivalent to around 1E9 Gy/s, spatially homogenized and tailored to the sample. The platform provides a unique infrastructure for translational research with protons at ultra-high dose rate.
Published: 2022

47. Investigation of laser reflectivity and transmissivity of laser-plasma interaction with thin foil targets

Author: (0000-0001-7332-7395) Umlandt, M. E. P., (0000-0002-3727-7017) Ziegler, T., (0000-0003-1739-0159) Bernert, C., (0000-0001-6994-2475) Garten, M., (0000-0002-6914-4083) Gaus, L., Göthel, I., (0000-0003-4861-5584) Kluge, T., (0000-0002-0638-6990) Kraft, S., (0000-0002-0275-9892) Kroll, F., (0000-0002-9556-0662) Metzkes-Ng, J., (0000-0003-0931-1350) Prencipe, I., (0000-0001-6200-6406) Rehwald, M., (0000-0003-4962-2153) Reimold, M., (0000-0003-4400-1315) Schlenvoigt, H.-P., (0000-0002-2828-5373) Vescovi Pinochet, M. A., (0000-0003-3926-409X) Zeil, K., (0000-0003-0390-7671) Schramm, U., (0000-0001-7332-7395) Umlandt, M. E. P., (0000-0002-3727-7017) Ziegler, T., (0000-0003-1739-0159) Bernert, C., (0000-0001-6994-2475) Garten, M., (0000-0002-6914-4083) Gaus, L., Göthel, I., (0000-0003-4861-5584) Kluge, T., (0000-0002-0638-6990) Kraft, S., (0000-0002-0275-9892) Kroll, F., (0000-0002-9556-0662) Metzkes-Ng, J., (0000-0003-0931-1350) Prencipe, I., (0000-0001-6200-6406) Rehwald, M., (0000-0003-4962-2153) Reimold, M., (0000-0003-4400-1315) Schlenvoigt, H.-P., (0000-0002-2828-5373) Vescovi Pinochet, M. A., (0000-0003-3926-409X) Zeil, K., and (0000-0003-0390-7671) Schramm, U.
Abstract: Ion acceleration by compact laser-plasma sources promises a variety of applications ranging from medical relevance to fusion experiments.Reaching the required beam quality parameters for those applications demands a very high level of understanding and control over the laserplasma interaction process. Central components in this context are the absorption of the electromagnetic laser field by the plasma and the quality of the resulting acceleration field structure. Measuring and analyzing unabsorbed light - as transmitted and/or specularly reflected parts - thus allows insight into properties of the underlying laser-plasma interaction. We experimentally investigate these interactions for high and low-contrast laser pulses with thin solid density foil targets at the Draco PW laser system (HZDR). The results of spectral, spatial, and energy analysis of transmitted and reflected light indicate changes in the plasma interaction and will be presented.
Published: 2022

48. Laser-proton acceleration developments at DRACO-PW enabling “in-vivo” radiobiology

Author: (0000-0002-3727-7017) Ziegler, T., (0000-0003-1739-0159) Bernert, C., (0000-0002-0582-1444) Beyreuther, E., (0000-0002-9859-2408) Brack, F.-E., (0000-0002-5845-000X) Cowan, T., (0000-0001-6994-2475) Garten, M., (0000-0002-6914-4083) Gaus, L., (0000-0003-4861-5584) Kluge, T., (0000-0002-0638-6990) Kraft, S., (0000-0002-0275-9892) Kroll, F., (0000-0002-9556-0662) Metzkes-Ng, J., (0000-0003-4128-5498) Pawelke, J., (0000-0003-4962-2153) Reimold, M., (0000-0001-6200-6406) Rehwald, M., (0000-0003-4400-1315) Schlenvoigt, H.-P., (0000-0001-7332-7395) Umlandt, M. E. P., (0000-0003-0390-7671) Schramm, U., (0000-0003-3926-409X) Zeil, K., (0000-0002-3727-7017) Ziegler, T., (0000-0003-1739-0159) Bernert, C., (0000-0002-0582-1444) Beyreuther, E., (0000-0002-9859-2408) Brack, F.-E., (0000-0002-5845-000X) Cowan, T., (0000-0001-6994-2475) Garten, M., (0000-0002-6914-4083) Gaus, L., (0000-0003-4861-5584) Kluge, T., (0000-0002-0638-6990) Kraft, S., (0000-0002-0275-9892) Kroll, F., (0000-0002-9556-0662) Metzkes-Ng, J., (0000-0003-4128-5498) Pawelke, J., (0000-0003-4962-2153) Reimold, M., (0000-0001-6200-6406) Rehwald, M., (0000-0003-4400-1315) Schlenvoigt, H.-P., (0000-0001-7332-7395) Umlandt, M. E. P., (0000-0003-0390-7671) Schramm, U., and (0000-0003-3926-409X) Zeil, K.
Abstract: We report technological developments at DRACO-PW to monitor and improve laser-plasma conditions resulting in a stable particle-source >60MeV, which in combination with our transport-beamline and high-quality dosimetry enabled first dose-controlled “in-vivo” studies with laser-driven protons.
Published: 2022

49. Ultra-short pulse laser-driven acceleration of protons to 80 MeV from density tailored cryogenic hydrogen jets

Author: (0000-0001-6200-6406) Rehwald, M., (0000-0003-1739-0159) Bernert, C., (0000-0002-9859-2408) Brack, F.-E., (0000-0002-5845-000X) Cowan, T., Curry, C. B., Fiuza, F., (0000-0001-6994-2475) Garten, M., (0000-0002-6914-4083) Gaus, L., Gauthier, M., Göde, S., Göthel, I., Glenzer, S. H., (0000-0003-1943-7141) Hübl, A., Kim, J. B., (0000-0003-4861-5584) Kluge, T., (0000-0002-0638-6990) Kraft, S., (0000-0002-0275-9892) Kroll, F., (0000-0002-9556-0662) Metzkes-Ng, J., (0000-0001-7858-0007) Löser, M., (0000-0001-9236-8037) Obst-Hübl, L., (0000-0003-4962-2153) Reimold, M., (0000-0003-4400-1315) Schlenvoigt, H.-P., Schoenwaelder, C., (0000-0003-0390-7671) Schramm, U., (0000-0002-4697-3014) Siebold, M., Treffert, F., (0000-0002-3727-7017) Ziegler, T., (0000-0003-3926-409X) Zeil, K., (0000-0001-6200-6406) Rehwald, M., (0000-0003-1739-0159) Bernert, C., (0000-0002-9859-2408) Brack, F.-E., (0000-0002-5845-000X) Cowan, T., Curry, C. B., Fiuza, F., (0000-0001-6994-2475) Garten, M., (0000-0002-6914-4083) Gaus, L., Gauthier, M., Göde, S., Göthel, I., Glenzer, S. H., (0000-0003-1943-7141) Hübl, A., Kim, J. B., (0000-0003-4861-5584) Kluge, T., (0000-0002-0638-6990) Kraft, S., (0000-0002-0275-9892) Kroll, F., (0000-0002-9556-0662) Metzkes-Ng, J., (0000-0001-7858-0007) Löser, M., (0000-0001-9236-8037) Obst-Hübl, L., (0000-0003-4962-2153) Reimold, M., (0000-0003-4400-1315) Schlenvoigt, H.-P., Schoenwaelder, C., (0000-0003-0390-7671) Schramm, U., (0000-0002-4697-3014) Siebold, M., Treffert, F., (0000-0002-3727-7017) Ziegler, T., and (0000-0003-3926-409X) Zeil, K.
Abstract: Laser plasma based particle accelerators have attracted great interest in fields where conventional accelerators reach limits based on size, cost or beam parameters. Designing future laser ion accelerators requires a high degree of control of the advanced acceleration schemes involved and predictive modelling capabilities. Here, we investigate the interaction of petawatt class laser pulses with a micrometer sized cryogenic hydrogen jet target. Controlled pre-expansion of the target by low intensity pre-pulses allowed for tailored density scans over more than two orders of magnitude. On-shot target characterization using two-color optical probing provided precise starting conditions for numerical simulations. For the optimal target density profile in the near critical regime proton energies of up to 80 MeV were observed which represents a two-fold increase with respect to the initial solid target case. Three-dimensional particle in cell simulations confirmed the transition between different acceleration mechanisms involved and suggested the magnetic-vortex regime to be responsible for the highest proton energies achieved.
Published: 2022

50. Laser-proton acceleration in the near-critical regime using density tailored cryogenic hydrogen jets

Author: (0000-0001-6200-6406) Rehwald, M. and (0000-0001-6200-6406) Rehwald, M.
Abstract: Modern particle accelerators are a key component of today’s research landscape and indispensable in industry and medicine. In special application areas, the portfolio of these facilities will be expanded by laser-driven compact plasma accelerators that generate short, high-intensity pulses of ions with unique beam properties. Though intensely explored by the community, scaling the maximum beam energies of laser-driven ion accelerators to the required level is one of the most significant challenges of this field. This endeavor is inherently linked to a fundamental understanding of the underlying acceleration processes. The prospect to effciently increase the beam energy relies on the ability to control the accelerating field structures beyond the well-established acceleration from the stationary target rear side. However, manipulating the interaction in such micrometer-sized accelerators proves to be challenging due to the transient nature of the plasma fields and requires precise tuning of the temporal laser pulse shape and the volumetric density distribution of the plasma target to a level that could so far not be achieved. This thesis investigates laser-proton acceleration using a cryogenic hydrogen target that combines the capabilities of predictive three-dimensional simulation and the in-situ realtime monitoring of the density distribution in the experiment to explore the fundamental physical principles of plasma based acceleration mechanisms. The corresponding experiments were performed at the DRACO laser facility at the Helmholtz-Zentrum Dresden-Rossendorf. The key to the success of these studies was the advancement of the cryogenic target system that generates a self-replenishing pure hydrogen jet. Using a mechanical chopping device, which protects the target system from the disruptive influence originating from the high-intensity interaction, allowed, for the first time, systematic experiments with a large number of laser shots in the harsh environment of th
Published: 2022

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