Search

Your search keyword '"Cowan, T"' showing total 155 results
Start Over Author "Cowan, T" Publication Year Range Last 3 years
155 results on '"Cowan, T"'

1. Plasma screening in mid-charged ions observed by K-shell line emission

Author

Šmıd, M., Humphries, O., Baehtz, C., Brambrink, E., Burian, T., Cho, M. S., Cowan, T. E., Gaus, L., Hájková, V., Juha, L., Konopkova, Z., Le, H. P., Makita, M., Pan, X., Preston, T., Schropp, A., Scott, H. A., Štefanıková, R., Vorberger, J., Wang, W., Zastrau, U., and Falk, K.

Subjects
Physics - Plasma Physics
Abstract

Dense plasma environment affects the electronic structure of ions via variations of the microscopic electrical fields, also known as plasma screening. This effect can be either estimated by simplified analytical models, or by computationally expensive and to date unverified numerical calculations. We have experimentally quantified plasma screening from the energy shifts of the bound-bound transitions in matter driven by the x-ray free electron laser (XFEL). This was enabled by identification of detailed electronic configurations of the observed K{\alpha}, K\b{eta} and K{\gamma} lines. This work paves the way for improving plasma screening models including connected effects like ionization potential depression and continuum lowering, which will advance the understanding of atomic physics in Warm Dense Matter regime.

Published
2024

2. Letter of Intent: Towards a Vacuum Birefringence Experiment at the Helmholtz International Beamline for Extreme Fields

Author

Ahmadiniaz, N., Bähtz, C., Benediktovitch, A., Bömer, C., Bocklage, L., Cowan, T. E., Edwards, J., Evans, S., Viñas, S. Franchino, Gies, H., Göde, S., Görs, J., Grenzer, J., Acosta, U. Hernandez, Heinzl, T., Hilz, P., Hippler, W., Huang, L. G., Humphries, O., Karbstein, F., Khademi, P., King, B., Kluge, T., Kohlfürst, C., Krebs, D., Laso-García, A., Lötzsch, R., Macleod, A. J., Marx-Glowna, B., Mosman, E. A., Nakatsutsumi, M., Paulus, G. G., Rahul, S. V., Randolph, L., Röhlsberger, R., Rohringer, N., Sävert, A., Sadashivaiah, S., Sauerbrey, R., Schlenvoigt, H. -P., Schmidt, S. M., Schramm, U., Schützhold, R., Schwinkendorf, J. -P., Seipt, D., Šmíd, M., Stöhlker, T., Toncian, T., Valialshchikov, M., Wipf, A., Zastrau, U., and Zepf, M.

Subjects
Physics - Instrumentation and Detectors, High Energy Physics - Experiment, High Energy Physics - Phenomenology, Physics - Optics
Abstract

Quantum field theory predicts a nonlinear response of the vacuum to strong electromagnetic fields of macroscopic extent. This fundamental tenet has remained experimentally challenging and is yet to be tested in the laboratory. A particularly distinct signature of the resulting optical activity of the quantum vacuum is vacuum birefringence. This offers an excellent opportunity for a precision test of nonlinear quantum electrodynamics in an uncharted parameter regime. Recently, the operation of the high-intensity laser ReLaX provided by the Helmholtz International Beamline for Extreme Fields (HIBEF) has been inaugurated at the High Energy Density (HED) scientific instrument of the European XFEL. We make the case that this worldwide unique combination of an x-ray free-electron laser and an ultra-intense near-infrared laser together with recent advances in high-precision x-ray polarimetry, refinements of prospective discovery scenarios, and progress in their accurate theoretical modelling have set the stage for performing an actual discovery experiment of quantum vacuum nonlinearity., Comment: 34 pages, 21 figures

Published
2024

3. Field-assisted birefringent Compton scattering

Author

Ahmadiniaz, N., Cowan, T. E., Ding, M., Lopez, M. A. Lopez, Sauerbrey, R., Shaisultanov, R., and Schützhold, R.

Subjects
High Energy Physics - Phenomenology, High Energy Physics - Theory, Physics - Optics
Abstract

Motivated by experimental initiatives such as the Helmholtz International Beamline for Extreme Fields (HIBEF), we study Compton scattering of x-rays at electrons in a strong external field (e.g., a strong optical laser) with special emphasis on the polarization-changing (i.e., birefringent) contribution on the amplitude level. Apart from being a potential background process for the planned vacuum birefringence experiments, this effect could be used for diagnostic purposes. Since the birefringent signal from free electrons (i.e., without the external field) vanishes in forward direction, the ratio of the birefringent and the normal (polarization conserving) contribution yields information about the field strength at the interaction point., Comment: 6 pages, 2 figures

Published
2022

4. Detection schemes for quantum vacuum diffraction and birefringence

Author

Ahmadiniaz, N., Cowan, T. E., Grenzer, J., Franchino-Viñas, S., Garcia, A. Laso, Šmíd, M., Toncian, T., Trejo, M. A., and Schützhold, R.

Subjects
Physics - Optics, High Energy Physics - Phenomenology, High Energy Physics - Theory
Abstract

Motivated by recent experimental initiatives, such as at the Helmholtz International Beamline for Extreme Fields (HIBEF) at the European X-ray Free Electron Laser (XFEL), we calculate the birefringent scattering of x-rays at the combined field of two optical (or near-optical) lasers and compare various scenarios. In order to facilitate an experimental detection of quantum vacuum diffraction and birefringence, special emphasis is placed on scenarios where the difference between the initial and final x-ray photons is maximized. Apart from their polarization, these signal and background photons may differ in propagation direction (corresponding to scattering angles in the mrad regime) and possibly energy., Comment: 7 pages, 1 figure

Published
2022

6. Shock compression experiments using the DiPOLE 100-X laser on the high energy density instrument at the European x-ray free electron laser: Quantitative structural analysis of liquid Sn

Author

Gorman, M. G., primary, McGonegle, D., additional, Smith, R. F., additional, Singh, S., additional, Jenkins, T., additional, McWilliams, R. S., additional, Albertazzi, B., additional, Ali, S. J., additional, Antonelli, L., additional, Armstrong, M. R., additional, Baehtz, C., additional, Ball, O. B., additional, Banerjee, S., additional, Belonoshko, A. B., additional, Benuzzi-Mounaix, A., additional, Bolme, C. A., additional, Bouffetier, V., additional, Briggs, R., additional, Buakor, K., additional, Butcher, T., additional, Di Dio Cafiso, S., additional, Cerantola, V., additional, Chantel, J., additional, Di Cicco, A., additional, Clarke, S., additional, Coleman, A. L., additional, Collier, J., additional, Collins, G. W., additional, Comley, A. J., additional, Coppari, F., additional, Cowan, T. E., additional, Cristoforetti, G., additional, Cynn, H., additional, Descamps, A., additional, Dorchies, F., additional, Duff, M. J., additional, Dwivedi, A., additional, Edwards, C., additional, Eggert, J. H., additional, Errandonea, D., additional, Fiquet, G., additional, Galtier, E., additional, Laso Garcia, A., additional, Ginestet, H., additional, Gizzi, L., additional, Gleason, A., additional, Goede, S., additional, Gonzalez, J. M., additional, Harmand, M., additional, Hartley, N. J., additional, Heighway, P. G., additional, Hernandez-Gomez, C., additional, Higginbotham, A., additional, Höppner, H., additional, Husband, R. J., additional, Hutchinson, T. M., additional, Hwang, H., additional, Lazicki, A. E., additional, Keen, D. A., additional, Kim, J., additional, Koester, P., additional, Konopkova, Z., additional, Kraus, D., additional, Krygier, A., additional, Labate, L., additional, Lee, Y., additional, Liermann, H.-P., additional, Mason, P., additional, Masruri, M., additional, Massani, B., additional, McBride, E. E., additional, McGuire, C., additional, McHardy, J. D., additional, Merkel, S., additional, Morard, G., additional, Nagler, B., additional, Nakatsutsumi, M., additional, Nguyen-Cong, K., additional, Norton, A.-M., additional, Oleynik, I. I., additional, Otzen, C., additional, Ozaki, N., additional, Pandolfi, S., additional, Peake, D. J., additional, Pelka, A., additional, Pereira, K. A., additional, Phillips, J. P., additional, Prescher, C., additional, Preston, T. R., additional, Randolph, L., additional, Ranjan, D., additional, Ravasio, A., additional, Redmer, R., additional, Rips, J., additional, Santamaria-Perez, D., additional, Savage, D. J., additional, Schoelmerich, M., additional, Schwinkendorf, J.-P., additional, Smith, J., additional, Sollier, A., additional, Spear, J., additional, Spindloe, C., additional, Stevenson, M., additional, Strohm, C., additional, Suer, T.-A., additional, Tang, M., additional, Toncian, M., additional, Toncian, T., additional, Tracy, S. J., additional, Trapananti, A., additional, Tschentscher, T., additional, Tyldesley, M., additional, Vennari, C. E., additional, Vinci, T., additional, Vogel, S. C., additional, Volz, T. J., additional, Vorberger, J., additional, Walsh, J. P. S., additional, Wark, J. S., additional, Willman, J. T., additional, Wollenweber, L., additional, Zastrau, U., additional, Brambrink, E., additional, Appel, K., additional, and McMahon, M. I., additional

Published
2024
Full Text
View/download PDF

8. 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

9. Phase retrieval by a conditional Wavelet Flow: applications to near-field X-ray holography

Author

(0000-0002-4166-9507) Aguilar, R. A., Zhang, Y., Willmann, A., Thiessenhusen, E., Dora, J., Greving, I., Hagemann, J., Lopes, A., Osenberg, M., Zeller-Plumhoff, B., Hoffmann, N., (0000-0002-8258-3881) Bussmann, M., (0000-0003-0390-7671) Schramm, U., (0000-0002-5845-000X) Cowan, T., (0000-0003-1761-2591) Kelling, J., (0000-0002-4166-9507) Aguilar, R. A., Zhang, Y., Willmann, A., Thiessenhusen, E., Dora, J., Greving, I., Hagemann, J., Lopes, A., Osenberg, M., Zeller-Plumhoff, B., Hoffmann, N., (0000-0002-8258-3881) Bussmann, M., (0000-0003-0390-7671) Schramm, U., (0000-0002-5845-000X) Cowan, T., and (0000-0003-1761-2591) Kelling, J.

Abstract

Phase retrieval is an ill-posed inverse problem with several applications in the fields of medical imaging and materials science. Conventional phase retrieval algorithms either simplify the problem by assuming certain object properties and optical propagation regimes or tuning a large number of free parameters. While the latter most often leads to good solutions for a wider application range, it is still a time-consuming process, even for experienced users. One way to circumvent this is by introducing a self-optimizing machine learning- based algorithm. Basing this on invertible networks such as normalising flows ensures good inversion, effi- cient sampling, and fast probability density estimation for large images and generally, complex-valued dis- tributions. Here, complex wavefield datasets are trained and tested on a normalising flows-based machine learning model for phase retrieval called conditional Wavelet Flow (cWF) and benchmarked against other conventional algorithms and baseline models. The cWF algorithm adds a conditioning network on top of the Wavelet Flow algorithm that is able to model the conditional data distribution of high resolution images of up to 1024 x 1024 pixels, which was not possible in other flow-based models. Additionally, cWF takes advantage of the parallelized training of different image resolutions, allowing for more efficient and fast training of large datasets. The trained algorithm is then applied to X-ray holography data wherein fast and high-quality image reconstruction is made possible.

Published
2024

10. 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

11. Leveraging Automatic Differentiation in Complex Model Fitting

Author

Thiessenhusen, E., Aguilar, R. A., (0000-0002-7162-7500) Smid, M., (0000-0003-4861-5584) Kluge, T., (0000-0002-8258-3881) Bussmann, M., (0000-0002-5845-000X) Cowan, T., Hoffmann, N., (0000-0003-1184-2097) Huang, L., (0000-0003-1761-2591) Kelling, J., Thiessenhusen, E., Aguilar, R. A., (0000-0002-7162-7500) Smid, M., (0000-0003-4861-5584) Kluge, T., (0000-0002-8258-3881) Bussmann, M., (0000-0002-5845-000X) Cowan, T., Hoffmann, N., (0000-0003-1184-2097) Huang, L., and (0000-0003-1761-2591) Kelling, J.

Abstract

Understanding laser-solid interactions is important for the development of laser-driven particle and photon sources, e.g., tumor therapy, astrophysics, and fusion. Currently, these interactions can only be modeled by simulations that need to be verified experimentally. Consequently, pump-probe experiments were conducted to examine the laser-plasma interaction that occurs when a high intensity laser hits a solid target. Since we aim for a femtosecond temporal and nanometer spatial resolution at European XFEL, we employ Small-Angle X-ray Scattering (SAXS) and Phase Contrast Imaging (PCI) that can each be approximated by an analytical propagator. In our reconstruction of the target, we employ a gradient descent algorithm that iteratively minimizes the error between experimental and synthetic patterns propagated from proposed target structures. By implementing the propagator in PyTorch we leverage the automatic differentiation capabilities, as well as the speed-up by computing the process on a GPU. We perform a scan of different initial parameters to find the global minimum, which is accelerated by batching multiple parallel reconstructions.

Published
2024

12. 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

13. Attenuated psychosis symptoms are related to working alliance between therapist and service user.

Author

Cowan, T., Millar, C., O'Donovan, K., Chibani, D., Reeves, G., Redman, S., Fitzgerald, J., Jay, S., Schiffman, J., and Rakhshan Rouhakhtar, P.

Abstract

Aim Methods Results Conclusion Many trials have demonstrated the efficacy of specific therapy modalities for individuals with attenuated psychosis symptoms (APS). Less is known regarding mechanisms behind positive outcomes, including the role of nonspecific therapeutic factors. This study explored working alliance (WA) in a clinic serving individuals with APS to see how WA changed across the course of treatment and its relation to APS.Session level APS and WA data was available for 12 individuals of diverse racial and gender identity, (M = 48 sessions each). Multilevel models with random intercepts tested change in WA and APS over time, and cross‐sectional and prospective relations.WA increased and APS decreased over time. Cross sectionally, WA and APS were inversely related. Prospective relations were non‐significant.When symptoms increase, therapists for individuals with APS should be attentive to potential disruptions in WA, though strong WA may be a cross‐sectional protective factor. [ABSTRACT FROM AUTHOR]

Published
2024
Full Text
View/download PDF

14. Investigation on laser absorption and x-ray radiation in microstructured titanium targets heated by short-pulse relativistic laser pulses

Author

Pan, X., primary, Šmíd, M., additional, Huang, L. G., additional, Kluge, T., additional, Bagnoud, V., additional, Brambrink, E., additional, Cowan, T. E., additional, Colgan, J., additional, Ebert, T., additional, Hartnagel, D., additional, Hesse, M., additional, Hornung, J., additional, Kleinschmidt, A., additional, Perez-Martin, P., additional, Neukirch, A., additional, Philipp, K., additional, Sander, S., additional, Schaumann, G., additional, Tebartz, A., additional, Zielbauer, B., additional, Roth, M., additional, and Falk, K., additional

Published
2024
Full Text
View/download PDF

17. Measuring the structure and equation of state of polyethylene terephthalate at megabar pressures

Author

Lütgert, J., Vorberger, J., Hartley, N. J., Voigt, K., Rödel, M., Schuster, A. K., Benuzzi-Mounaix, A., Brown, S., Cowan, T. E., Cunningham, E., Döppner, T., Falcone, R. W., Fletcher, L. B., Galtier, E., Glenzer, S. H., Laso Garcia, A., Gericke, D. O., Heimann, P. A., Lee, H. J., McBride, E. E., Pelka, A., Prencipe, I., Saunders, A. M., Schölmerich, M., Schörner, M., Sun, P., Vinci, T., Ravasio, A., and Kraus, D.

Published
2021
Full Text
View/download PDF

19. Debates in the Digital Humanities 2023

Author

Hannah, Matthew N., additional, Smith, Astrid J., additional, Whearty, Bridget, additional, Ghorbaninejad, Masoud, additional, Gibson, Nathan P., additional, Wrisley, David Joseph, additional, Brown, Michelle Lee, additional, Whaanga, Hēmi, additional, Lewis, Jason Edward, additional, Ventura, Gabriela Baeza, additional, Cotera, María Eugenia, additional, Merchant, Linda García, additional, Gauthereau, Lorena, additional, Villarroel, Carolina, additional, Bench, Harmony, additional, Elswit, Kate, additional, Chang, Kent K., additional, Suther, Tonia, additional, Cifor, Marika, additional, Cowan, T. L., additional, Rault, Jas, additional, Garcia, Patricia, additional, Frazier, Nishani, additional, Hyman, Christy, additional, Green, Hilary N., additional, Gibson, Abraham, additional, Boyles, Christina, additional, Petersen, Andrew Boyles, additional, Jacob, Arun, additional, Martin, Alison, additional, Guldi, Jo, additional, Pugh, Emily, additional, Chapman, Rico Devara, additional, Quintanilla, Olivia, additional, Horcasitas, Jeanelle, additional, Salter, Anastasia, additional, Stanfill, Mel, additional, Walsh, Melanie, additional, Dombrowski, Quinn, additional, Burns, Patrick J., additional, Keralis, Spencer D. C., additional, Mirza, Rafia, additional, Seale, Maura, additional, Brett, Megan R., additional, Otis, Jessica Marie, additional, Kelly, Mills, additional, LeBlanc, Zoe, additional, Sharpe, Celeste Tường Vy, additional, Wieringa, Jeri, additional, Malazita, James, additional, Glover, Kaiama L., additional, Daut, Marlene L., additional, Joseph-Gabriel, Annette K., additional, Gallon, Kim, additional, Parham, Marisa, additional, Soumahoro, Maboula, additional, Niang, Mame-Fatou, additional, Jones, Martha S., additional, and Johnson, Jessica Marie, additional

Published
2023
Full Text
View/download PDF

20. 390 Examining the risk factors for worsened glucocorticoid morbidity in a prospective, multicentre, international study of patients with autoimmune blistering diseases

Author

Johal, J., primary, Cowan, T., additional, Bilgic, A., additional, Bozca, B., additional, Enli, S., additional, Yang, B., additional, Daneshpazhooh, M., additional, Boziou, M., additional, Patsatsi, A., additional, Mundin, C., additional, Quizon, M., additional, Kakuta, R., additional, Takahashi, H., additional, Wilson, A., additional, Zeng, F., additional, and Murrell, D., additional

Published
2023
Full Text
View/download PDF

21. 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

22. Atomic Population Kinetics for Particle in Cell

Author

Marre, B. E., Huebl, A., (0000-0003-3396-6154) Bastrakov, S., (0000-0002-8258-3881) Bussmann, M., (0000-0003-1642-0459) Widera, R., (0000-0003-0390-7671) Schramm, U., (0000-0002-5845-000X) Cowan, T., (0000-0003-4861-5584) Kluge, T., Marre, B. E., Huebl, A., (0000-0003-3396-6154) Bastrakov, S., (0000-0002-8258-3881) Bussmann, M., (0000-0003-1642-0459) Widera, R., (0000-0003-0390-7671) Schramm, U., (0000-0002-5845-000X) Cowan, T., and (0000-0003-4861-5584) Kluge, T.

Abstract

Atomic Population Kinetics for ParticleInCell Standard atomic physics models in PIC simulation either neglect excited states, predict atomic state population in post processing only, or assume quasi-thermal plasma conditions. This is no longer sufficient for high-intensity short-pulse laser generated plasmas, due to their non-equilibrium, transient and non-thermal plasma conditions, which are now becoming accessible in XFEL experiments at HIBEF (EuropeanXFEL), SACLA (Japan) or at MEC (LCLS/SLAC). To remedy this, we have developed a new extension for our PIC simulation framework PIConGPU to allow us to model atomic population kinetics in-situ in PIC-Simulations, in transient plasmas and without assuming any temperatures. This extension is based on a reduced atomic state model, which is directly coupled to the existing PIC-simulation and for which the atomic rate equation is solved explicitly in time, depending on local interaction spectra and with feedback to the host simulation. This allows us to model de-/excitation and ionization of ions in transient plasma conditions, as typically encountered in laser accelerator plasmas. This new approach to atomic physics modeling will be very useful in plasma emission prediction, plasma condition probing with XFELs and better understanding of isochoric heating processes, since all of these rely on an accurate prediction of atomic state populations inside transient plasmas.

Published
2023

23. 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

24. Field-assisted birefringent Compton scattering

Author

(0000-0002-0558-9454) Ahmadiniaz, N., (0000-0002-5845-000X) Cowan, T., (0000-0002-3690-1690) Ding, M., Lopez Lopez, M. A., Sauerbrey, R., Shaisultanov, R., Schützhold, R., (0000-0002-0558-9454) Ahmadiniaz, N., (0000-0002-5845-000X) Cowan, T., (0000-0002-3690-1690) Ding, M., Lopez Lopez, M. A., Sauerbrey, R., Shaisultanov, R., and Schützhold, R.

Abstract

Motivated by experimental initiatives such as the Helmholtz International Beamline for ExtremeFields (HIBEF), we study Compton scattering of x-rays at electrons in a strong external field (e.g., a strong optical laser) with special emphasis on the polarization-changing (i.e., birefringent) contribution on the amplitude level. Apart from being a potential background process for the planned vacuum birefringence experiments, this effect could be used for diagnostic purposes. Since the birefringent signal from free electrons (i.e., without the external field) vanishes in forward direction, the ratio of the birefringent and the normal (polarization conserving) contribution yields information about the field strength at the interaction point.

Published
2023

25. 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

26. 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

27. Detection schemes for quantum vacuum diffraction and birefringence

Author

(0000-0002-0558-9454) Ahmadiniaz, N., (0000-0002-5845-000X) Cowan, T., Grenzer, J., Franchino-Vinas, S., (0000-0002-7671-0901) Laso García, A., (0000-0002-7162-7500) Smid, M., (0000-0001-7986-3631) Toncian, T., Trejo Espinosa, M. A., Schützhold, R., (0000-0002-0558-9454) Ahmadiniaz, N., (0000-0002-5845-000X) Cowan, T., Grenzer, J., Franchino-Vinas, S., (0000-0002-7671-0901) Laso García, A., (0000-0002-7162-7500) Smid, M., (0000-0001-7986-3631) Toncian, T., Trejo Espinosa, M. A., and Schützhold, R.

Abstract

Motivated by recent experimental initiatives, such as at the Helmholtz International Beamline for Extreme Fields (HIBEF) at the European X-ray Free Electron Laser (XFEL), we calculate the birefringent scattering of x-rays at the combined field of two optical (or near-optical) lasers and compare various scenarios. % In order to facilitate an experimental detection of quantum vacuum diffraction and birefringence, special emphasis is placed on scenarios where the initial and final x-ray photons differ not just in polarization, but also in propagation direction (corresponding to scattering angles in the mrad regime) and possibly energy.

Published
2023

28. X-ray polarimetry and its application to strong-field quantum electrodynamics

Author

Yu, Q., Xu, D., Shen, B., (0000-0002-5845-000X) Cowan, T., (0000-0003-4400-1315) Schlenvoigt, H.-P., Yu, Q., Xu, D., Shen, B., (0000-0002-5845-000X) Cowan, T., and (0000-0003-4400-1315) Schlenvoigt, H.-P.

Abstract

Polarimetry is a highly sensitive method to quantify changes of the polarization state of light when passing through matter and is therefore widely applied in material science. The progress of synchrotron and X-Ray Free Electron Laser (XFEL) sources has led to significant developments of X-ray polarizers, opening perspectives for new applications of polarimetry to study source and beamline parameters as well as sample characteristics. X-ray polarimetry has shown to date a polarization purity of \num{<1.4e-11}, enabling detection of very small signals from ultrafast phenomena. A prominent application is the detection of vacuum birefringence. Vacuum birefringence is predicted in Quantum Electrodynamics (QED) and expected to be probed by combining an XFEL with a petawatt-class optical laser. We review how source and optical elements affect X-ray polarimeters in general and what qualities are required for detection of vacuum birefringence.

Published
2023

29. Heating in multi-layer targets at ultra-high intensity laser irradiation and the impact of density oscillation

Author

(0009-0001-0047-1051) Paschke-Brühl, F.-L., (0000-0003-4861-5584) Kluge, T., Marre, B. E., (0000-0001-6994-2475) Garten, M., (0000-0003-0390-7671) Schramm, U., (0000-0002-5845-000X) Cowan, T., (0000-0003-1184-2097) Huang, L., Banjafar, M., Randolph, L., (0000-0003-0868-4745) Nakatsutsumi, M., (0009-0001-0047-1051) Paschke-Brühl, F.-L., (0000-0003-4861-5584) Kluge, T., Marre, B. E., (0000-0001-6994-2475) Garten, M., (0000-0003-0390-7671) Schramm, U., (0000-0002-5845-000X) Cowan, T., (0000-0003-1184-2097) Huang, L., Banjafar, M., Randolph, L., and (0000-0003-0868-4745) Nakatsutsumi, M.

Abstract

Article about Heating in multi-layered target upon UHI laser irradiation

Published
2023

30. 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

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

Author

(0000-0003-1739-0159) Bernert, C., 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., Vescovi Pinochet, M. A., (0000-0002-3727-7017) Ziegler, T., (0000-0003-3926-409X) Zeil, K., (0000-0003-1739-0159) Bernert, C., 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., 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

32. Strong-field physics prospects at 50 keV at EuXFEL

Author

(0000-0002-6182-1481) Hernandez Acosta, U., (0000-0001-8965-1149) Steiniger, K., (0000-0002-8258-3881) Bussmann, M., (0000-0002-5845-000X) Cowan, T., (0000-0002-6182-1481) Hernandez Acosta, U., (0000-0001-8965-1149) Steiniger, K., (0000-0002-8258-3881) Bussmann, M., and (0000-0002-5845-000X) Cowan, T.

Abstract

Some studies of applying a 50 keV XFEL for strong-field physics, modelled by the interaction with an electron beam, were presented. The process of electron-positron pair production in strong fields deviates from the well-known perturbative result in weak field backgrounds. In a strong field background, an electron can directly emit a photon, generating a pair via the trident process. Using 50 keV photons, only about 5 MeV kinetic electron energy is required to reach the trident threshold, which is available by electron guns or laser acceleration (in solids, or wakefield). The trident process can also be used to test models for dark matter candidates. Using the proposed massive “dark photon”, the assumed mass and coupling to ordinary could be determined more precisely than with hadron experiments. Certain exclusion regions can be scanned, but the trident experiment could also be used to detect dark matter (instead of excluding certain mass/coupling ranges) because there is full control over the QED background. A second scheme is the interaction of hard x-rays with electrons in the presence of an intense, infrared few-cycle laser light field. It allows to study of laser-assisted Compton scattering, Breit Wheeler pair production and trident, where during the peaks of the few-cycle IR laser field, spectral features are introduced. A (quasi-) continuous X-ray beam (as in a synchrotron) is not sufficient for strong-field studies as high intensity is required. A user community, similar to established synchrotron or XFEL users, may not exist yet. Many colleagues work on theoretical models, but more experimentalists will emerge with upcoming experimental capabilities at XFELs. The LUXE experiment at DESY, and the detection of QED vacuum birefringence at HED/HIBEF, EuXFEL, are examples of such developments.

Published
2023

33. 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

34. 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) 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., (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) 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., (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

35. 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

36. Leveraging Automatic Differentiation in Complex Model Fitting

Author

Thiessenhusen, E., Aguilar, R. A., (0000-0002-7162-7500) Smid, M., (0000-0002-8258-3881) Bussmann, M., (0000-0003-4861-5584) Kluge, T., (0000-0002-5845-000X) Cowan, T., (0000-0003-1184-2097) Huang, L., Hoffmann, N., (0000-0003-1761-2591) Kelling, J., Thiessenhusen, E., Aguilar, R. A., (0000-0002-7162-7500) Smid, M., (0000-0002-8258-3881) Bussmann, M., (0000-0003-4861-5584) Kluge, T., (0000-0002-5845-000X) Cowan, T., (0000-0003-1184-2097) Huang, L., Hoffmann, N., and (0000-0003-1761-2591) Kelling, J.

Abstract

Understanding laser-solid interactions is important for the development of laser-driven particle and photon sources, e.g., tumor therapy, astrophysics, and fusion. Currently, these interactions can only be modeled by simulations that need to be verified experimentally. Consequently, pump-probe experiments were conducted to examine the laser-plasma interaction that occurs when a high intensity laser hits a solid target. Since we aim for a femtosecond temporal and nanometer spatial resolution at European XFEL, we employ Small-Angle X-ray Scattering (SAXS) and Phase Contrast Imaging (PCI) that can each be approximated by an analytical propagator. In our reconstruction of the target, we employ a gradient descent algorithm that iteratively minimizes the error between experimental and synthetic patterns propagated from proposed target structures. By implementing the propagator in PyTorch we leverage the automatic differentiation capabilities, as well as the speed-up by computing the process on a GPU. We perform a scan of different initial parameters to find the global minimum, which is accelerated by batching multiple parallel reconstructions. The fully differentiable implementation of a forward function may serve as a physically-constraining loss, enabling training with unpaired data or unsupervised training of neural networks to predict the initial parameters for the gradient descent fit.

Published
2023

37. Visualizing Ultrafast Kinetic Instabilities in Laser-Driven Solids using X-ray Scattering

Author

Ordyna, P., (0000-0002-8258-3881) Bussmann, M., (0000-0002-6914-4083) Gaus, L., Grenzer, J., Gutt, C., (0000-0003-1184-2097) Huang, L., (0000-0002-7671-0901) Laso García, A., (0000-0001-6994-2475) Garten, M., Höppner, H., Humpries, O., Marre, B. E., (0000-0002-9556-0662) Metzkes-Ng, J., Nakatsutsumi, M., Öztürk, Ö., (0000-0002-3882-510X) Pan, X., Paschke-Brühl, F.-L., Pelka, A., (0000-0003-0931-1350) Prencipe, I., Randolph, L., (0000-0003-4400-1315) Schlenvoigt, H.-P., (0000-0002-7162-7500) Smid, M., (0000-0002-4195-2038) Stefanikova, R., Thiessenhusen, E., (0000-0001-7986-3631) Toncian, T., (0000-0003-3926-409X) Zeil, K., (0000-0003-0390-7671) Schramm, U., (0000-0002-5845-000X) Cowan, T., (0000-0003-4861-5584) Kluge, T., Ordyna, P., (0000-0002-8258-3881) Bussmann, M., (0000-0002-6914-4083) Gaus, L., Grenzer, J., Gutt, C., (0000-0003-1184-2097) Huang, L., (0000-0002-7671-0901) Laso García, A., (0000-0001-6994-2475) Garten, M., Höppner, H., Humpries, O., Marre, B. E., (0000-0002-9556-0662) Metzkes-Ng, J., Nakatsutsumi, M., Öztürk, Ö., (0000-0002-3882-510X) Pan, X., Paschke-Brühl, F.-L., Pelka, A., (0000-0003-0931-1350) Prencipe, I., Randolph, L., (0000-0003-4400-1315) Schlenvoigt, H.-P., (0000-0002-7162-7500) Smid, M., (0000-0002-4195-2038) Stefanikova, R., Thiessenhusen, E., (0000-0001-7986-3631) Toncian, T., (0000-0003-3926-409X) Zeil, K., (0000-0003-0390-7671) Schramm, U., (0000-0002-5845-000X) Cowan, T., and (0000-0003-4861-5584) Kluge, T.

Abstract

Ultra-intense lasers that ionize and accelerate electrons in solids to near the speed of light can lead to kinetic instabilities that alter the laser absorption and subsequent electron transport, isochoric heating, and ion acceleration. These instabilities can be difficult to characterize, but a novel approach using X-ray scattering at keV energies allows for their visualization with femtosecond temporal resolution on the few nanometer mesoscale. Our experiments on laser-driven flat silicon membranes show the development of structure with a dominant scale of $~60\unit{nm}$ in the plane of the laser axis and laser polarization, and $~95\unit{nm}$ in the vertical direction with a growth rate faster than $0.1/\mathrm{fs}$. Combining the XFEL experiments with simulations provides a complete picture of the structural evolution of ultra-fast laser-induced instability development, indicating the excitation of surface plasmons and the growth of a new type of filamentation instability. These findings provide new insight into the ultra-fast instability processes in solids under extreme conditions at the nanometer level with important implications for inertial confinement fusion and laboratory astrophysics.

Published
2023

38. 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

39. 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

40. Recovery of release cloud from laser shock-loaded graphite and hydrocarbon targets: in search of diamonds

Author

Schuster, A K, primary, Voigt, K, additional, Klemmed, B, additional, Hartley, N J, additional, Lütgert, J, additional, Zhang, M, additional, Bähtz, C, additional, Benad, A, additional, Brabetz, C, additional, Cowan, T, additional, Döppner, T, additional, Erb, D J, additional, Eychmüller, A, additional, Facsko, S, additional, Falcone, R W, additional, Fletcher, L B, additional, Frydrych, S, additional, Ganzenmüller, G C, additional, Gericke, D O, additional, Glenzer, S H, additional, Grenzer, J, additional, Helbig, U, additional, Hiermaier, S, additional, Hübner, R, additional, Laso Garcia, A, additional, Lee, H J, additional, MacDonald, M J, additional, McBride, E E, additional, Neumayer, P, additional, Pak, A, additional, Pelka, A, additional, Prencipe, I, additional, Prosvetov, A, additional, Rack, A, additional, Ravasio, A, additional, Redmer, R, additional, Reemts, D, additional, Rödel, M, additional, Schoelmerich, M, additional, Schumacher, D, additional, Tomut, M, additional, Turner, S J, additional, Saunders, A M, additional, Sun, P, additional, Vorberger, J, additional, Zettl, A, additional, and Kraus, D, additional

Published
2022
Full Text
View/download PDF

41. Recovery of release cloud from laser shock-loaded graphite and hydrocarbon targets: in search of diamonds

Author

Schuster, A. K., Voigt, K., Klemmed, B., Hartley, N. J., Lütgert, J., Zhang, M., Bähtz, C., Benad, A., Brabetz, C., Cowan, T., Döppner, T., Erb, D. J., Eychmüller, A., Facsko, S., Falcone, R. W., Fletcher, L. B., Frydrych, S., Ganzenmüller, G. C., Gericke, D. O., Glenzer, S. H., Grenzer, J., Helbig, U., Hiermaier, S., Hübner, R., Laso Garcia, A., Lee, H. J., MacDonald, M. J., McBride, E. E., Neumayer, P., Pak, A., Pelka, A., Prencipe, I., Prosvetov, A., Rack, A., Ravasio, A., Redmer, R., Reemts, D., Rödel, M., Schoelmerich, M., Schumacher, D., Tomut, M., Turner, S. J., Saunders, A. M., Sun, P., Vorberger, J., Zettl, A., Kraus, D., Schuster, A. K., Voigt, K., Klemmed, B., Hartley, N. J., Lütgert, J., Zhang, M., Bähtz, C., Benad, A., Brabetz, C., Cowan, T., Döppner, T., Erb, D. J., Eychmüller, A., Facsko, S., Falcone, R. W., Fletcher, L. B., Frydrych, S., Ganzenmüller, G. C., Gericke, D. O., Glenzer, S. H., Grenzer, J., Helbig, U., Hiermaier, S., Hübner, R., Laso Garcia, A., Lee, H. J., MacDonald, M. J., McBride, E. E., Neumayer, P., Pak, A., Pelka, A., Prencipe, I., Prosvetov, A., Rack, A., Ravasio, A., Redmer, R., Reemts, D., Rödel, M., Schoelmerich, M., Schumacher, D., Tomut, M., Turner, S. J., Saunders, A. M., Sun, P., Vorberger, J., Zettl, A., and Kraus, D.

Abstract

This work presents first insights into the dynamics of free-surface release clouds from dynamically compressed polystyrene and pyrolytic graphite at pressures up to 200 GPa, where they transform into diamond or lonsdaleite, respectively. These ejecta clouds are released into either vacuum or various types of catcher systems, and are monitored with high-speed recordings (frame rates up to 10 MHz). Molecular dynamics simulations are used to give insights to the rate of diamond preservation throughout the free expansion and the catcher impact process, highlighting the challenges of diamond retrieval. Raman spectroscopy data show graphitic signatures on a catcher plate confirming that the shock-compressed PS is transformed. First electron microscopy analyses of solid catcher plates yield an outstanding number of different spherical-like objects in the size range between ten(s) up to hundreds of nanometres, which are one type of two potential diamond candidates identified. The origin of some objects can unambiguously be assigned, while the history of others remains speculative.

Published
2022

42. X-ray radiation transport in GPU accelerated Particle In Cell simulations

Author

Ordyna, P., (0000-0003-4861-5584) Kluge, T., (0000-0002-5845-000X) Cowan, T., (0000-0003-0390-7671) Schramm, U., Ordyna, P., (0000-0003-4861-5584) Kluge, T., (0000-0002-5845-000X) Cowan, T., and (0000-0003-0390-7671) Schramm, U.

Abstract

Ultra-high-intensity laser pulse interactions with solid density targets are of central importance for modern accelerator physics, Inertial Confinement Fusion(ICF) and astrophysics. In order to meet the requirements of real-world applications, a deeper understanding of the underlying plasma dynamics, including plasma instabilities and acceleration mechanisms, is needed. X-ray radiation plays a substantial role in plasma physics, either as an integral part of a physical system itself or as a useful diagnostic, hence it should be included in computational models. Therefore, we bring a Monte Carlo based X-ray radiation transport module into our Particle In Cell simulation framework PIConGPU. It allows, among others, for Thompson scattering, e.g. for small-angle X-ray scattering (SAXS), and Faraday effect calculation for X-ray polarimetry - as online, in-situ diagnostics.

Published
2022

43. 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

44. 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

45. 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

46. 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

47. 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

48. 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

49. Ultrafast melting of Warm Dense Cu studied by x-ray spectroscopy

Author

(0000-0002-7162-7500) Smid, M., (0000-0001-9759-1166) Köhler, A., Bowers, B., Chang, Y.-Y., (0000-0001-9129-4208) Couperus Cabadağ, J. P., (0000-0003-1184-2097) Huang, L., Kozlová, M., Kurz, T., La Berge, M., Pan, X., (0000-0002-2767-9995) Perez-Martin, P., Ruiz De Los Panos, I. L., (0000-0002-2769-4749) Schöbel, S., (0000-0001-5926-9192) Vorberger, J., (0000-0003-4362-3438) Zarini, O., (0000-0002-5845-000X) Cowan, T., (0000-0003-0390-7671) Schramm, U., (0000-0002-4626-0049) Irman, A., (0000-0001-5975-776X) Falk, K., (0000-0002-7162-7500) Smid, M., (0000-0001-9759-1166) Köhler, A., Bowers, B., Chang, Y.-Y., (0000-0001-9129-4208) Couperus Cabadağ, J. P., (0000-0003-1184-2097) Huang, L., Kozlová, M., Kurz, T., La Berge, M., Pan, X., (0000-0002-2767-9995) Perez-Martin, P., Ruiz De Los Panos, I. L., (0000-0002-2769-4749) Schöbel, S., (0000-0001-5926-9192) Vorberger, J., (0000-0003-4362-3438) Zarini, O., (0000-0002-5845-000X) Cowan, T., (0000-0003-0390-7671) Schramm, U., (0000-0002-4626-0049) Irman, A., and (0000-0001-5975-776X) Falk, K.

Abstract

We present novel experimental results of ultra fast heating of Warm Dense Cu diagnosed by means of x-ray absorption and emission spectroscopy carried out at the Draco laser facility at HZDR in 2021. A thin Cu foil was directly heated to few eV temperature by an ultra short laser pulse (40 fs, 2e15 W/cm2) and probed with variable delay in the range 0.2-20 ps by a laser-driven betatron radiation. This betatron radiation, created by a laser wakefield accelerator, is an unique x-ray source with its ultra short duration and broadband spectrum, therefore ideally suited for studies of non-equilibrium dense plasmas while its high brightness allows for single-shot measurement. The sample is studied via the X-ray absorption spectroscopy in the region above the Cu K-edge. This method provides temporally-resolved information about both the ionic structure of the matter and its temperature during the process of ultrafast heating and melting of the material. The measured spectra are understood and analyzed by using Ab initio simulations and the temporal evoution of heatig and melting is compared to PIC simulations to infer the electron to ion energy transer.

Published
2022

50. Population Kinetics for Particle in Cell Simulations

Author

Marre, B. E., (0000-0003-1943-7141) Hübl, A., (0000-0003-3396-6154) Bastrakov, S., (0000-0002-8258-3881) Bussmann, M., (0000-0003-1642-0459) Widera, R., (0000-0003-0390-7671) Schramm, U., (0000-0002-5845-000X) Cowan, T., (0000-0003-4861-5584) Kluge, T., Marre, B. E., (0000-0003-1943-7141) Hübl, A., (0000-0003-3396-6154) Bastrakov, S., (0000-0002-8258-3881) Bussmann, M., (0000-0003-1642-0459) Widera, R., (0000-0003-0390-7671) Schramm, U., (0000-0002-5845-000X) Cowan, T., and (0000-0003-4861-5584) Kluge, T.

Abstract

Population Kinetics for PIC Standard atomic physics models in PIC simulation either neglect excited states, predict atomic state population in post processing only, or assume quasi-thermal plasma conditions. This is no longer sufficient for high-intensity short-pulse laser generated plasmas, due to their non-equilibrium, transient and non-thermal plasma conditions, which are now becoming accessible in XFEL experiments at HIBEF (EuropeanXFEL), SACLA (Japan) or at MEC (LCLS/SLAC). To remedy this, we have developed a new extension for our ParticleInCell simulation framework PIConGPU to allow us to model atomic population kinetics in situ in PIC-Simulations, in transient plasmas and without assuming temperatures. This extension is based on a reduced atomic state model, which is directly coupled to the existing PIC-simulation and for which the atomic rate equation is solved explicitly in time, depending on local interaction spectra and with feedback to the host simulation. This allows us to model de-/excitation and ionization and of ions in transient plasma conditions, as typically encountered in laser generated plasmas. This new approach to atomic physics modeling will be very useful in plasma emission prediction, plasma condition probing with XFELs and better understanding of isochoric heating processes, since all of these rely on an accurate prediction of atomic state populations inside transient plasmas.

Published
2022

Catalog

Books, media, physical & digital resources
See catalog results