130 results on '"Nishiuchi, Mamiko"'
Search Results
2. Enhanced ion acceleration from transparency-driven foils demonstrated at two ultraintense laser facilities
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Dover, Nicholas P., Ziegler, Tim, Assenbaum, Stefan, Bernert, Constantin, Bock, Stefan, Brack, Florian-Emanuel, Cowan, Thomas E., Ditter, Emma J., Garten, Marco, Gaus, Lennart, Goethel, Ilja, Hicks, George S., Kiriyama, Hiromitsu, Kluge, Thomas, Koga, James K., Kon, Akira, Kondo, Kotaro, Kraft, Stephan, Kroll, Florian, Lowe, Hazel F., Metzkes-Ng, Josefine, Miyatake, Tatsuhiko, Najmudin, Zulfikar, Püschel, Thomas, Rehwald, Martin, Reimold, Marvin, Sakaki, Hironao, Schlenvoigt, Hans-Peter, Shiokawa, Keiichiro, Umlandt, Marvin E. P., Schramm, Ulrich, Zeil, Karl, and Nishiuchi, Mamiko
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- 2023
- Full Text
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3. Ultrarelativistic Fe plasma with GJ/cm3 energy density created by femtosecond laser pulses.
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Alkhimova, Mariya, Skobelev, Igor, Pikuz, Tatiana, Ryazantsev, Sergey, Sakaki, Hironao, Pirozhkov, Alexander S., Esirkepov, Timur Zh., Sagisaka, Akito, Dover, Nicholas P., Kondo, Kotaro, Ogura, Koichi, Fukuda, Yuji, Kiriyama, Hiromitsu, Nishitani, Keita, Pikuz, Sergey, Kando, Masaki, Kodama, Ryosuke, Kondo, Kiminori, and Nishiuchi, Mamiko
- Abstract
The generation of a plasma with an ultrahigh energy density of 1.2 GJ/cm
3 (which corresponds to about 12 Gbar pressure) is investigated by irradiating thin stainless-steel foils with high-contrast femtosecond laser pulses with relativistic intensities of up to 1022 W/cm2 . The plasma parameters are determined by X-ray spectroscopy. The results show that most of the laser energy is absorbed by the plasma at solid density, indicating that no pre-plasma is generated in the current experimental setup. [ABSTRACT FROM AUTHOR]- Published
- 2024
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4. Denoising application for electron spectrometer in laser-driven ion acceleration using a Simulation-supervised Learning based CDAE
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Miyatake, Tatsuhiko, Shiokawa, Keiichiro, Sakaki, Hironao, Dover, Nicholas P., Nishiuchi, Mamiko, Lowe, Hazel F., Kondo, Kotaro, Kon, Akira, Kando, Masaki, Kondo, Kiminori, and Watanabe, Yukinobu
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- 2021
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5. (Sub-)Picosecond Surface Correlations of Femtosecond Laser Excited Al-Coated Multilayers Observed by Grazing-Incidence X-ray Scattering.
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Randolph, Lisa, Banjafar, Mohammadreza, Yabuuchi, Toshinori, Baehtz, Carsten, Bussmann, Michael, Dover, Nicholas P., Huang, Lingen, Inubushi, Yuichi, Jakob, Gerhard, Kläui, Mathias, Ksenzov, Dmitriy, Makita, Mikako, Miyanishi, Kohei, Nishiuchi, Mamiko, Öztürk, Özgül, Paulus, Michael, Pelka, Alexander, Preston, Thomas R., Schwinkendorf, Jan-Patrick, and Sueda, Keiichi
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FEMTOSECOND pulses ,X-ray scattering ,ULTRASHORT laser pulses ,FEMTOSECOND lasers ,SMALL-angle X-ray scattering ,SURFACE dynamics ,MULTILAYERS ,SURFACE morphology - Abstract
Femtosecond high-intensity laser pulses at intensities surpassing 10
14 W/cm2 can generate a diverse range of functional surface nanostructures. Achieving precise control over the production of these functional structures necessitates a thorough understanding of the surface morphology dynamics with nanometer-scale spatial resolution and picosecond-scale temporal resolution. In this study, we show that single XFEL pulses can elucidate structural changes on surfaces induced by laser-generated plasmas using grazing-incidence small-angle X-ray scattering (GISAXS). Using aluminium-coated multilayer samples we distinguish between sub-picosecond (ps) surface morphology dynamics and subsequent multi-ps subsurface density dynamics with nanometer-depth sensitivity. The observed subsurface density dynamics serve to validate advanced simulation models representing matter under extreme conditions. Our findings promise to open new avenues for laser material-nanoprocessing and high-energy-density science. [ABSTRACT FROM AUTHOR]- Published
- 2024
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- View/download PDF
6. Status and progress of the J-KAREN-P high intensity laser system at QST
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Kiriyama, Hiromitsu, Pirozhkov, Alexander S., Nishiuchi, Mamiko, Fukuda, Yuji, Ogura, Koichi, Sagisaka, Akito, Miyasaka, Yasuhiro, Sakaki, Hironao, Dover, Nicholas P., Kondo, Kotaro, Lowe, Hazel F., Kon, Akira, Koga, James K., Esirkepov, Timur Zh, Nakanii, Nobuhiko, Huang, Kai, Kando, Masaki, and Kondo, Kiminori
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- 2020
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7. Observation of the inhomogeneous spatial distribution of MeV ions accelerated by the hydrodynamic ambipolar expansion of clusters
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Kanasaki, Masato, Jinno, Satoshi, Sakaki, Hironao, Faenov, Anatoly Ya., Pikuz, Tatiana A., Nishiuchi, Mamiko, Kiriyama, Hiromitsu, Kando, Masaki, Sugiyama, Akira, Kondo, Kiminori, Matsui, Ryutaro, Kishimoto, Yasuaki, Morishima, Kunihiro, Watanabe, Yukinobu, Scullion, Clare, Smyth, Ashley G., Alejo, Aaron, Doria, Domenico, Kar, Satyabrata, Borghesi, Marco, Oda, Keiji, Yamauchi, Tomoya, and Fukuda, Yuji
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- 2015
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8. Induction heating for desorption of surface contamination for high-repetition laser-driven carbon-ion acceleration.
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Kojima, Sadaoki, Miyatake, Tatsuhiko, Sakaki, Hironao, Kuroki, Hiroyoshi, Shimizu, Yusuke, Harada, Hisanori, Inoue, Norihiro, Dinh, Thanh Hung, Hata, Masayasu, Hasegawa, Noboru, Mori, Michiaki, Ishino, Masahiko, Nishiuchi, Mamiko, Kondo, Kotaro, Nishikino, Masaharu, Kando, Masaki, Shirai, Toshiyuki, and Kondo, Kiminori
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SURFACE contamination ,LANGMUIR isotherms ,NICKEL films ,CATALYSIS ,INDUCTION heating ,LITHIUM-ion batteries ,MATRIX-assisted laser desorption-ionization - Abstract
This study reports the first experimental demonstration of surface contamination cleaning from a high-repetition supply of thin-tape targets for laser-driven carbon-ion acceleration. The adsorption of contaminants containing protons, mainly water vapor and hydrocarbons, on the surface of materials exposed to low vacuum (>10
−3 Pa) suppresses carbon-ion acceleration. The newly developed contamination cleaner heats a 5-μm-thick nickel tape to over 400 °C in 100 ms by induction heating. In the future, this heating method could be scaled to laser-driven carbon-ion acceleration at rates beyond 10 Hz. The contaminant hydrogen is eliminated from the heated nickel surface, and a carbon source layer—derived from the contaminant carbon—is spontaneously formed by the catalytic effect of nickel. The species of ions accelerated from the nickel film heated to various temperatures have been observed experimentally. When the nickel film is heated beyond ∼150 °C, the proton signal considerably decreases, with a remarkable increase in the number and energy of carbon ions. The Langmuir adsorption model adequately explains the temperature dependence of desorption and re-adsorption of the adsorbed molecules on a heated target surface, and the temperature required for proton-free carbon-ion acceleration can be estimated. [ABSTRACT FROM AUTHOR]- Published
- 2023
- Full Text
- View/download PDF
9. Laser Output Performance and Temporal Quality Enhancement at the J-KAREN-P Petawatt Laser Facility.
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Kiriyama, Hiromitsu, Miyasaka, Yasuhiro, Kon, Akira, Nishiuchi, Mamiko, Sagisaka, Akito, Sasao, Hajime, Pirozhkov, Alexander S., Fukuda, Yuji, Ogura, Koichi, Kondo, Kotaro, Nakanii, Nobuhiko, Mashiba, Yuji, Dover, Nicholas P., Chang, Liu, Kando, Masaki, Bock, Stefan, Ziegler, Tim, Püschel, Thomas, Schlenvoigt, Hans-Peter, and Zeil, Karl
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OPTICAL parametric amplifiers ,PARABOLIC reflectors ,DIGITAL transformation ,WAVEFRONTS (Optics) ,DIGITAL technology ,LASERS ,ADAPTIVE optics ,HIGH-intensity focused ultrasound - Abstract
We described the output performance and temporal quality enhancement of the J-KAREN-P petawatt laser facility. After wavefront correction using a deformable mirror, focusing with an f/1.3 off-axis parabolic mirror delivered a peak intensity of 10
22 W/cm2 at 0.3 PW power levels. Technologies to improve the temporal contrast were investigated and tested. The origins of pre-pulses generated by post-pulses were identified and the elimination of most pre-pulses by removal of the post-pulses with wedged optics was achieved. A cascaded femtosecond optical parametric amplifier based on the utilization of the idler pulse rather than the signal pulse was developed for the complete elimination of the remaining pre-pulses. The orders of magnitude enhancement of the pedestal before the main pulse were obtained by using a higher surface quality of the convex mirror in the Öffner stretcher. A single plasma mirror was installed in the J-KAREN-P laser beam line for further contrast improvement of three orders of magnitude. The above developments indicate, although it has not been directly measured, the contrast can be as high as approximately 1015 up to 40 ps before the main pulse. We also showed an overview of the digital transformation (DX) of the system, enabling remote and automated operation of the J-KAREN-P laser facility. [ABSTRACT FROM AUTHOR]- Published
- 2023
- Full Text
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10. The effect of laser contrast on generation of highly charged Fe ions by ultra-intense femtosecond laser pulses
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Faenov, Anatoly Ya., Alkhimova, Maria A., Pikuz, Tatiana A., Skobelev, Igor Yu., Nishiuchi, Mamiko, Sakaki, Hironao, Pirozhkov, Alexander S., Sagisaka, Akito, Dover, Nicholas P., Kondo, Kotaro, Ogura, Koichi, Fukuda, Yuji, Kiriyama, Hiromitsu, Andreev, Alexander, Nishitani, Keita, Miyahara, Takumi, Watanabe, Yukinobu, Pikuz, Jr., Sergey A., Kando, Masaki, Kodama, Ruosuke, and Kondo, Kiminori
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- 2017
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11. Prepulse and amplified spontaneous emission effects on the interaction of a petawatt class laser with thin solid targets
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Esirkepov, Timur Zh., Koga, James K., Sunahara, Atsushi, Morita, Toshimasa, Nishikino, Masaharu, Kageyama, Kei, Nagatomo, Hideo, Nishihara, Katsunobu, Sagisaka, Akito, Kotaki, Hideyuki, Nakamura, Tatsufumi, Fukuda, Yuji, Okada, Hajime, Pirozhkov, Alexander S., Yogo, Akifumi, Nishiuchi, Mamiko, Kiriyama, Hiromitsu, Kondo, Kiminori, Kando, Masaki, and Bulanov, Sergei V.
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- 2014
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12. A high energy component of the intense laser-accelerated proton beams detected by stacked CR-39
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Kanasaki, Masato, Hattori, Atsuto, Sakaki, Hironao, Fukuda, Yuji, Yogo, Akifumi, Jinno, Satoshi, Nishiuchi, Mamiko, Ogura, Koichi, Kondo, Kiminori, Oda, Keiji, and Yamauchi, Tomoya
- Published
- 2013
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13. Development of carbon thin film for Laser‐driven heavy ion acceleration using a XeCl excimer laser
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Kusaba, Mitsuhiro, Nigo, Fumitaka, Kondo, Kotaro, Nishiuchi, Mamiko, Sakaki, Hironao, Kiriyama, Hiromitsu, Hashida, Masaki, Sakabe, Shuji, Kotaro, Kondo, Mamiko, Nishiuchi, Hironao, Sakaki, Hiromitsu, Kiriyama, and Masaki, Hashida
- Abstract
The carbon thin film as a target for laser‐driven heavy ion acceleration has been developed using the carbonization of polyimide induced by the irradiation of a XeCl excimer laser. The relationship between the depth of the crater produced by the laser irradiation and the laser fluence were measured in order to clear the carbonization mechanisms of polyimide. The melting threshold of polyimide was estimated to 0.058 J/cm2. It is found that the carbonization is induced by the irradiation with the laser fluence around or under the threshold.
- Published
- 2020
14. Single-shot measurement of post-pulse-generated pre-pulse in high power laser systems
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Kon, Akira, Nishiuchi, Mamiko, Kiriyama, Hiromitsu, Kando, Masaki, Bock, Stefan, Ziegler , Tim, Pueschel, Thomas, Zeil, Karl, Schramm, Ulrich, and Kondo, Kiminori
- Abstract
In this study, a detailed investigation of the dynamics of the generation of pre-pulse by post-pulses is presented, using single-shot self-referenced spectral interferometry (SRSI). The capability of SRSI in terms of the single-shot measurement of the temporal contrast of high power laser systems has been experimentally demonstrated. The results confirm that the energy levels of the pre-pulses increase proportional to the square of the B-integral parametrizing the nonlinearity of the amplifier chain.
- Published
- 2020
15. Experimental investigation on temporal contrast of pre-pulses by post-pulses in a petawatt laser facility
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Kiriyama, Hiromitsu, Miyasaka, Yasuhiro, Sagisaka, Akito, Ogura, Koichi, Nishiuchi, Mamiko, Pirozhkov, Alexander, Fukuda, Yuuji, Kando, Masaki, Kondo, Kiminori, Hiromitsu, Kiriyama, Yasuhiro, Miyasaka, Akito, Sagisaka, Koichi, Ogura, Mamiko, Nishiuchi, Yuji, Fukuda, Masaki, Kando, and Kiminori, Kondo
- Abstract
We experimentally explore the generation of pre-pulses by post-pulses, created through internal reflection in the optical components, by the non-linear process associated with the B-integral in the laser chain of the petawatt facility J-KAREN-P. At large time delay between the main and the post-pulses, we have found that the pre-pulses are not generated from their counterpart post-pulses at an identical time difference before the main pulse and the temporal shapes of the pre-pulses are greatly distorted asymmetrically. We have also observed the peak intensities of the pre-pulses are drastically suppressed compared to the expected value at small time delay. We briefly describe the origins of the pre-pulses generated by the post-pulses and demonstrate the removal of the pre-pulses by switching to optical components with a small wedge angle at our petawatt laser facility.
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- 2020
16. Diagnosis of Transverse Emittance in Laser-Driven Ion Beam
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Miyatake, Tatsuhiko, Dinh, Thanh-Hung, Kando, Masaki, Kojima, Sadaoki, Kondo, Kiminori, Kondo, Kotaro, Nishikino, Masaharu, Nishiuchi, Mamiko, Sakaki, Hironao, Takemoto, Ibuki, and Watanabe, Yukinobu
- Subjects
MC3: Novel Particle Sources and Acceleration Techniques ,Physics::Accelerator Physics ,Accelerator Physics - Abstract
Ion beam produced in laser-driven ion acceleration by ultra-intense lasers has characteristics of high peak cur-rent and low emittance. These characteristics become an advantage to operate the request for the beam applica-tion. Therefore, we study how to control the parameters with the laser-plasma interaction. Here, we used 2D Particle-in-Cell code to simulate the laser-driven ion acceleration and investigated the results in terms of transverse emittance, beam current, and brightness. The laser spot size and target thickness were changed in the simulation. And, these qualitative results show that interaction target thickness is a major factor in controlling beam characteristics., Proceedings of the 13th International Particle Accelerator Conference, IPAC2022, Bangkok, Thailand
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- 2022
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17. Self-supporting tetrahedral amorphous carbon films consisting of multilayered structure prepared using filtered arc deposition
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Toru, HARIGAI, Yu, MIYAMOTO, Masafumi, YAMANO, Tsuyoshi, TANIMOTO, Yoshiyuki, SUDA, Hirofumi, TAKIKAWA, Takeshi, KAWANO, Nishiuchi, Mamiko, Sakaki, Hironao, Kondo, Kiminori, Satoru, KANEKO, Shinsuke, KUNITSUGU, Mamiko, Nishiuchi, Hironao, Sakaki, and Kiminori, Kondo
- Abstract
Self-supporting 110-nm-thick tetrahedral amorphous carbon (ta-C) films with a multilayered structure were fabricated as a carbon film target for the laser-driven ion acceleration. The self-supporting ta-C films consisted of three layers with the thicknesses of 35 nm, 40 nm, and 35 nm thick, and the film density of 3.0 g/cm3, 2.7 g/cm3, and 3.0 g/cm3, respectively. The multilayered ta-C film was fabricated using the T-shape filtered arc deposition method on a Si substrate coated water-soluble material. Silk fibroin and dextran were used as the water-soluble material. The water-soluble material formed between a ta-C film and a Si substrate was dissolved, and then, the ta-C film released from the substrate. Thick single-layer ta-C films partially peeled off on the water-soluble material and broke during the dissolving process. Self-supporting ta-C films were obtained by scooping the released ta-C film on a perforated substrate. The laser was irradiated on the self-supporting ta-C films, and the ta-C film with a higher film thickness and/or film density showed a higher laser irradiation tolerance.
- Published
- 2019
18. Characteristics of a laser-produced proton beam improved by a synchronous RF field
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Wakita, Akihisa, Iwashita, Yoshihisa, Shirai, Toshiyuki, Ikegami, Masahiro, Tongu, Hiromu, Souda, Hikaru, Mori, Michiaki, Yogo, Akifumi, Orimo, Satoshi, Nishiuchi, Mamiko, Ogura, Koichi, Sagisaka, Akito, Ma, J.-L., Pirozhkov, Alexander S., Kiriyama, Hiromitsu, Nakai, Yoshiki, Shimomura, Takuya, Tanoue, Manabu, Akutsu, Atsushi, Okada, Hiroshi, Motomura, Tomohiro, Kondo, Shuji, Kanazawa, Shuhei, Sugiyama, Hironori, Daido, Hiroyuki, and Noda, Akira
- Published
- 2009
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19. High-intensity laser-driven particle and electromagnetic wave sources for science, industry, and medicine
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Sagisaka, Akito, Daido, Hiroyuki, Pirozhkov, Alexander S., Mori, Michiaki, Yogo, Akifumi, Ogura, Koichi, Orimo, Satoshi, Nishiuchi, Mamiko, Ma, Jinglong, Kiriyama, Hiromitsu, Kanazawa, Shuhei, Kondo, Shuji, Nakai, Yoshiki, Shimomura, Takuya, Tanoue, Manabu, Akutsu, Atsushi, Okada, Hajime, Motomura, Tomohiro, Kawachi, Tetsuya, Bulanov, Sergei V., Esirkepov, Timur Zh., Nashima, Shigeki, Hosoda, Makoto, Nagatomo, Hideo, Oishi, Yuji, Nemoto, Koshichi, Choi, Il Woo, Lee, Seong Ku, and Lee, Jongmin
- Published
- 2009
- Full Text
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20. New method to measure the rise time of a fast pulse slicer for laser ion acceleration research
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Mori, Michiaki, Yogo, Akifumi, Kiriyama, Hiromitsu, Nishiuchi, Mamiko, Ogura, Koichi, Orimo, Satoshi, Ma, Jinglong, Sagisaka, Akito, Kanazawa, Shuhei, Kondo, Shuji, Nakai, Yoshiki, Akutsu, Atsushi, Yamamoto, Yoichi, Shimomura, Takuya, Tanoue, Manabu, Nakamura, Shu, Shirai, Toshiyuki, Iwashita, Yoshihisa, Noda, Akira, Oishi, Yuji, Nayuki, Takuya, Fujii, Takashi, Nemoto, Koshichi, Choi, Il Woo, Yu, Tae Jun, Ko, Do-Kyeong, Lee, Jongmin, Daido, Hiroyuki, Esirkepov, Timur, Bulanov, Sergei V., Bolton, Paul R., and Kimura, Toyoaki
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Ionic mobility -- Research ,Laser-plasma interactions -- Evaluation ,Pulsed radiation -- Observations ,Electrons -- Emission ,Electrons -- Observations ,Business ,Chemistry ,Electronics ,Electronics and electrical industries - Abstract
A dependence of cutoff proton kinetic energy on laser prepulse duration has been observed. Amplified spontaneous emission pedestal duration is controlled by a fast electrooptic pulse slicer where the rise time is estimated to be 130 ps. We demonstrate a new correlated spectral technique for determining this rise time using a stretched frequency-chirped pulse. Index Terms--Intense laser, ion beam, laser-plasma interaction, plasma accelerator, proton accelerators.
- Published
- 2008
21. Simultaneous generation of UV harmonics and protons from a thin-foil target with a high-intensity laser
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Sagisaka, Akito, Daido, Hiroyuki, Pirozhkov, Alexander S., Ma, Jinglong, Yogo, Akifumi, Ogura, Koichi, Orimo, Satoshi, Mori, Michiaki, Nishiuchi, Mamiko, Kawachi, Tetsuya, Bulanov, Sergei V., Esirkepov, Timur Zh., Oishi, Yuji, Nayuki, Takuya, Fujii, Takashi, Nemoto, Koshichi, and Nagatomo, Hideo
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Thin films -- Properties ,Ultraviolet radiation -- Properties ,Harmonics (Electric waves) -- Evaluation ,Lasers -- Usage ,Lasers -- Properties ,Protons -- Properties ,Dielectric films -- Properties ,Laser ,Business ,Chemistry ,Electronics ,Electronics and electrical industries - Abstract
We observe UV harmonics and protons with a 7.5-[micro]m-thick polyimide target irradiated with a high-intensity Ti:sapphire laser. The laser intensity dependence of UV harmonics and proton signal is measured by varying the distance between the target surface and the best focus of the laser beam. In the case of appropriate condition for proton generation with a maximum energy of ~2.7 MeV, the weak broad spectrum in the UV region is generated. The UV harmonics of up to the fourth order are generated as the target is moved away from the best focus position. In this condition, the maximum energy of protons is reduced to ~1 MeV. The simultaneous generation of the harmonies and protons is observed at the amplified spontaneous emission intensities between ~5 x [10.sup.11] and ~5 x [10.sup.12] W/[cm.sup.2]. Index Terms--Harmonics, high-intensity laser, proton, thin-foil target.
- Published
- 2008
22. Dynamics of Laser-driven Heavy Ion Acceleration Claried by Ion Charge States
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Nishiuchi, Mamiko, Dover, NicholasPeter, Hata , Masayasu, Sakaki, Hironao, Kondo, Kotaro, Lowe, HazelFrances, Miyahara, Takumi, Kiriyama, Hiromitsu, Kevin Koga, James, Iwata, Natsumi, Alklhimova, Mariya, Pirozhkov, Alexander, Faenov, Alatory, Tatiana, Pikuz, Sagisaka, Akito, Watanabe, Yukinobu, Kando, Masaki, Kondo, Kiminori, Ditter, EmmaJane, Ettlinger, Oliver, Hicks, George, Zuflkar, Najmudin, Ziegler, Tim, Zeil, Karl, Schramm, Ulrich, and Sentoku, Yasuhiko
- Subjects
Physics::Plasma Physics - Abstract
Motivated by the development of next-generation heavy ion sources, we have investigated the ionization and acceleration dynamics of an ultra intense laser-driven high-Z silver target, experimentally, numerically and analytically. Using a novel ion measurement technique allowing us to uniquely identify silver ions, we experimentally demonstrate generation of highly charged silver ions (Z=45+2 ????2) with energies of >20 MeV/nucleon (>2.2 GeV) from sub-micron silver targets driven by a laser with intensity 51021 W/cm2, with increasing ion energy and charge state for decreasing target thickness. We show that although target pre-expansion by the unavoidable rising edge of state-of-the-art high power lasers can limit proton energies, it is advantageous for heavy ion acceleration. Two-dimensional particle-in-cell simulations show that the Joule heating in the target bulk results in a high temperature (10 keV) solid density plasma, leading to the generation of high particle number highly charged ions (Z=40+2 ????2 , &10 MeV/nucleon) via electron collisional ionization, which are extracted and accelerated with a small divergence by an extreme sheath eld at the target rear. However, with reduced target thickness this favorable acceleration is degraded due to the target deformation via laser hole boring, which accompanies higher energy ions with higher charge states but in an uncontrollable manner. Our elucidation of the fundamental processes of high intensity laser driven ionization and ion acceleration provides a path for improving the control and parameters of laser driven heavy ion sources, a key component for next-generation heavy ion accelerators.
- Published
- 2020
23. New algorithm using L1 regularization for measuring electron energy spectra
- Author
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Sakaki, Hironao, Nishiuchi, Mamiko, Dover, NicholasPeter, Lowe, HazelFrances, Kondo, Kotaro, Kon, Akira, Kando, Masaki, Tachibana, Yasuhiko, Obata, Takayuki, Shiokawa, Keiichiro, Miyatake, Tatsuhiko, and Watanabe, Yukinobu
- Abstract
Retrieving the spectrum of physical radiation from experimental measurements typically involves using a mathematical algorithm to deconvolve the instrument response function from the measured signal. However, in the field of signal processing known as "Source Separation", which refers to the process of computationally retrieving the separate source components that generate an overlapping signal on the detector, the deconvolution process can become an ill-posed problem and crosstalk complicates the separation of the individual sources. To overcome this problem, we have designed a magnetic spectrometer for inline electron energy spectrum diagnosis and developed an analysis algorithm using techniques applicable to the problem of Source Separation. An unknown polychromatic electron spectrum is calculated by sparse coding using a Gaussian basis function and an L1 regularization algorithm with a sparsity constraint. This technique is verified by a specially designed magnetic field electron spectrometer. We use Monte Carlo simulations of the detector response to Maxwellian input energy distributions with electron temperatures of 5.0, 10.0 and 15.0 MeV to show that the calculated sparse spectrum can reproduce the input spectrum with an optimum energy bin width automatically selected by the L1 regularization. The spectra are reproduced with high accuracy of less than 4.0 % error, without an initial value. The technique is then applied to experimental measurements of intense laser accelerated electron beams from solid targets. Our analysis concept of spectral retrieval and automatic optimization of energy bin width by sparse coding could form the basis of a novel diagnostic method for spectroscopy.
- Published
- 2020
24. Denoising technique of an in-line electron energy spectrometer based on the feature filtering
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Sakaki, Hironao, Shiokawa, Keiichiro, Miyatake, Tatsuhiko, Nishiuchi, Mamiko, Kondo, Kotaro, Dover, NicholasPeter, Lowe, HazelFrances, Kon, Akira, Kando, Masaki, and Watanabe, Yukinobu
- Subjects
Computer Science::Computer Vision and Pattern Recognition ,ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION - Abstract
On the experiment for laser-driven ion acceleration at J-KAREN-P[1] with pulse repetition rates of 0.1 Hz, the angular distribution of electron spectrum is diagnosed by multiple electron spectrometers. The electron spectrometer with comprising a bending magnet, a CCD camera and a scintillator is placed in the main vacuum chamber. When the laser focus on the target, many radiations generated in the main vacuum chamber, therefore, CCD camera is exposed to the radiation and distorted the measured images. We need to develop a new technique for removing noise (denoising) from a noisy image and recovering a true measurement image. In recent years, with the development of machine learning methods such as Deep-Learning, "Deep-Learning based Feature filtering" that uses a feature value of an image obtained from machine learning as a base and reproduces a true image from a noisy image is developed[2]. This filtering technique is a new technique of reconstructing a denoising image by separating noise and true data with the feature value of the true-image data. This technique expectes to be effective for the denoising of radiation. In order to demonstrate the feature filtering method, we make a pseudo-measured image generated from an ideal simulation of electron spectroscopy (using as the true-image data), and the noise-image data which make from the measured radiation noise convoluted with the pseudo-measured image (using as the noise-image data). Then, the ideal feature base is obtained by machine learning from the true-image data and the noise-image data, the feature filtering of the actually measured data is verified by using these the ideal feature base. In this report, we show the denoising performance of the feature filtering compared with "median filter" which is generally used for filtering of radiation noise., HEDS2020
- Published
- 2020
25. Characterization of thin-foil preformed plasmas for high-intensity laser plasma interactions
- Author
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Sagisaka, Akito, Daido, Hiroyuki, Pirozhkov, Alexander S., Ogura, Koichi, Orimo, Satoshi, Mori, Michiaki, Nishiuchi, Mamiko, Yogo, Akifumi, Kado, Masataka, Nakamura, Shu, Iwashita, Yoshihisa, Shirai, Toshiyuki, Noda, Akira, and Nagatomo, Hideo
- Published
- 2006
- Full Text
- View/download PDF
26. Research on Laser Acceleration and Coherent X-RAY Generation Using J-KAREN-P Laser
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Pirozhkov, Alexander, Nishiuchi, Mamiko, Kiriyama, Hiromitsu, Kon, Akira, Sakaki, Hironao, Fukuda, Yuuji, Dover, NicholasPeter, Sekiguchi, Kenji, Nishitani, Keita, Sagisaka, Akito, A., Pikuz T., Ya., Faenov A., Ogura, Koichi, Hayashi, Y., Kotaki, Hideyuki, Zh., Esirkepov T., HUANG, KAI, Nakanii, Nobuhiko, Kondo, Kiminori, Kevin, Koga James, and Kondo, Katsuya
- Subjects
Physics::Instrumentation and Detectors ,Nuclear Theory ,Physics::Accelerator Physics ,Nuclear Experiment - Abstract
The upgrade status of J-KAREN is presented. The upgrade includes two pilot experiments in order to show the laser performance on target. The first experiment is to generate high-energy ions from thin-foil target. The second is the high-order harmonic at a relativistic intensity. Currently, laser acceleration of protons is being tested and we have obtained 32 MeV protons.
- Published
- 2018
27. UV Harmonic Generation and Laser-Driven Proton Acceleration from Thin-Foil Target
- Author
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Sagisaka, Akito, Pirozhkov, Alexander, Nishiuchi, Mamiko, Ogura, Koichi, Sakaki, Hironao, Ya., Faenov Anatoly, A., Pikuz Tatiana, Timur, Esirkepov, Bulanov, Sergey, Kando, Masaki, Kiriyama, Hiromitsu, and Kondo, Kiminori
- Subjects
Physics::Accelerator Physics ,Nuclear Experiment - Abstract
UV harmonics and protons are observed with a high-intensity Ti:sapphire laser. High-energy protons are generated with an aluminum thin-foil target. Simultaneously with the high-energy protons the generation of third- and fourth- order harmonics are observed in the reflection direction by using a high-intensity high-contrast laser.
- Published
- 2018
28. Characterization of the plasma mirror system at the J-KAREN-P facility.
- Author
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Kon, Akira, Nishiuchi, Mamiko, Fukuda, Yuji, Kondo, Kotaro, Ogura, Koichi, Sagisaka, Akito, Miyasaka, Yasuhiro, Dover, Nicholas P., Kando, Masaki, Pirozhkov, Alexander S., Daito, Izuru, Chang, Liu, Choi, Il Woo, Nam, Chang Hee, Ziegler, Tim, Schlenvoigt, Hans-Peter, Zeil, Karl, Schramm, Ulrich, and Kiriyama, Hiromitsu
- Subjects
- *
PLASMA stability , *LASER plasmas - Abstract
We report on the design and characterization of the plasma mirror system installed on the J-KAREN-P laser at the Kansai Photon Science Institute, National Institutes for Quantum Science and Technology. The reflectivity of the single plasma mirror system exceeded 80%. In addition, the temporal contrast was improved by two orders of magnitude at 1 ps before the main pulse. Furthermore, the laser near-field spatial distribution after the plasma mirror was kept constant at plasma mirror fluence of less than 100 kJ/cm2. We also present the results of investigating the difference and the fluctuation in energy, pulse width and pointing stability with and without the plasma mirror system. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
29. electric fields extracting highly charged heavy ions by the short pulse high intensity laser J-KAREN-P system
- Author
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Nishiuchi, Mamiko, Sakaki, Hironao, Kiriyama, Hiromitsu, Dover, NicholasPeter, Kevin Koga, James, Kondo, Kotaro, Watanabe, Yukinobu, Kando, Masaki, Kondo, Kiminori, and Yasuhiko, Sentoku
- Subjects
Physics::Plasma Physics - Abstract
High intensity short pulse laser interacting with solide density target produces high energy density (HED) plasma in the new parameter range. By using high intensity short pulse laser J-KAREN system with intensity 5x10^21 Wcm^-2 interacting with a 500 nm -thick silver target, we demonstrated the generation of such HED plasma and extracted high charge state silver ions (~+40) with energies of ~15 MeV/u from the plasma. The high charge states of the silver ions are resulted from the collisional ionization in the target due to the hot bulk electron temperature ~10 keV reached within femtoseconds. These ions are injected into and accelerated by the extremely high field of ~50 TV/m at the target rear. The result is a promising technique for generating energetic ion beams and opens a way for developing next-generation heavy ion accelerators., ICMRE 2019
- Published
- 2019
30. Highly charged heavy ion acceleration from a high temperature solid heated by J-KAREN laser system
- Author
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Dover, NicholasPeter, Sakaki, Hironao, Kondo, Kotaro, Kiriyama, Hiromitsu, Kevin Koga, James, Alkhimova, MARIYA, Pirozhkov, Alexander, Anatory, FAENOV, Tatiana, PIKUZ, Sagisaka, Akito, Watanabe, Yukinobu, Kando, Masaki, Kondo, Kiminori, Yasuhiko, Sentoku, and Nishiuchi, Mamiko
- Abstract
The interaction of relativistically intense short pulse (~few tens of fs) laser pulse with solid material generates quasi-static electric fields with strengths of > TV/m are produced within a short distance of less than m [1]. Thanks to the very strong field gradient, the field can accelerate ions beyond MeV within a micron. Unlike the acceleration of low-Z ions, acceleration of the high-Z ion is more complicated because charge state distribution should be controlled for pursuing higher acceleration efficiency or for manipulating a spectral shape of the ions. However, all the proposed laser-driven acceleration mechanisms, including the most investigated and easy to implement mechanism, Target Normal Sheath Acceleration (TNSA) [2], are far from being fully understood in the sense of ionization mechanisms. To address this issue, we investigate the ionization mechanisms in HED plasma produced by a laser pulse of peak intensity ~5x1021 Wcm????2 interacting with a silver 500 nm target by using J-KAREN laser system KPSI, QST [3]. Even the J-KAREN laser is high contrast laser system the pulses show not completely ideal (Gaussian-like) temporal shape. The existence of the rising edge is an inherent feature of high power laser systems based on highly non-linear processes and eliminating this rising edge is challenging, even when applying pulse cleaning techniques such as plasma mirrors and/or a plasma shutter. The rising edge interacts with target in advance to the main pulse and can prematurely expand the target resulting in reduction of proton cutoff energies. This is a serious barrier for not only proton acceleration, however we found this temporal shape can be a beneficial effect on heavy ion acceleration from the bulk of the target. In the experiment we observed that silver ions with a charge state of ~ +40 are accelerated up to ~15 MeV/u with the particle number of (2±1)x106 ion/shot within an energy range of 10-15 MeV/u. With the help of hydrodynamic, particle-in-cell (PIC) simulations and analytical estimates, we find out that the ions in the contaminant layer pre-expands and effectively detaches from the target, still keeping the target material intact, so that the bulk ions are exposed to stronger sheath fields and accelerated to higher energies. The highly charged energetic silver ions are generated via electron collisions in the hot (~6 keV electron temperature) solid plasma. The reported heavy ion acceleration mechanism is in unexplored physical regime, which has been generated for the first time via interaction with a laser with an ultra-high intensity using the state-of-the-art laser system J-KAREN., Laser-Plasma Accelerator Workshop 2019参加
- Published
- 2019
31. Ion identification method using photostimulable phosphor detector
- Author
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Sakaki, Hironao, Iwata, Yoshiyuki, Nishiuchi, Mamiko, Miyahara, Takumi, Shiokawa, Keiichiro, Kondo, Kotaro, Manabe, Seiya, Dover, NicholasPeter, Lowe, HazelFrances, Watanabe, Yukinobu, Kando, Masaki, and Kondo, Kiminori
- Subjects
Physics::Plasma Physics - Abstract
At upgraded petawatt-class J-KARENP laser experiment, we have demonstrated the high charge-states heavy ions to high energies through the interaction of an intense and short laser pulse with a solid target. Petawatt-class laser-solid interaction experiments produce to ion species from the base metal, include contamination ions, with the energy spectrum ranging from a few MeV/u to a few tens MeV/u. And these ion beams have peculiar characteristics; good emittance, high charge-states, and particle flux. Several possible applications of these ion beams have been suggested as injectors for heavy ion accelerators and in the hadron therapy . In order to achieve these applications in the future, it is required to control the ion beam parameters using some scaling models which are made from obtain spectra of each ions. The laser-solid interaction experiments generally use to get the ion spectrum the Thomson parabola and photostimulable phosphor detector (Imaging plate). The imaging plate has a wide dynamic reigns and few tens micrometer resolution. It diagnose a single ion track which made from the deposited energies on the imaging plate. Therefore, from the information of the ion track, an identification of ion species should be possible. Details of an identification of ion species from the single track on the imaging plate will be discussed., International Conference on High Energy Density Science 2019
- Published
- 2019
32. Denoising for a real-time electron spectrometer using a Convolution Neural Network
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Shiokawa, Keiichiro, Sakaki, Hironao, Nishiuchi, Mamiko, Kondo, Kotaro, Dover, NicholasPeter, Lowe, HazelFrances, Kon, Akira, Watanabe, Yukinobu, and Kando, Masaki
- Abstract
Petawatt class laser-solid interaction experiments [1] are conducted at the ultra-short pulse (40fs), ultra-intense (10^22 W/cm^2) J-KAREN-P laser system[2]. An electron spectrometer (ESM) that can detect up to a maximum electron energy of 30 MeV was used for measurement of the temperature of the hot electron population emitted by the laser-driven plasma. The ESM consists of a 1.0 T magnet, scintillator (DRZ-high) and CCD camera which were placed in the vacuum chamber in order to make real-time measurements. Not only electrons and x-rays emitted by the plasma, but also secondary electron and x-ray emission generated in the vacuum chamber are detected by the ESM. This secondary emission creates background noise which is randomly scattered over the whole of the observed ESM image. Recently, Statistical-Learning methods for analysis of “big data” have progressed rapidly allowing a novel denoising technique, known as the Denoising Auto Encoder (DAE) [3], to be established. The DAE is based on a Convolution Neural Network that transforms features extracted from the raw image to produce a processed image in which the unwanted noise component has been digitally removed. This technique has been shown to be suitable for processing the ESM images for the purpose of denoising. In this report, we compare conventional denoising methods with the DAE., HEDS2019
- Published
- 2019
33. Experimental investigation of sheath-driven proton beam parameters in the ultra-short pulse, ultra-high intensity regime
- Author
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Nishiuchi, Mamiko, Kevin Koga, James, Sakaki, Hironao, Kondo, Kotaro, Kiriyama, Hiromitsu, Miyahara, Takumi, Ogura, Koichi, Pirozhkov, Alexander, Sagisaka, Akito, Kando, Masaki, Kondo, Kiminori, and Dover, NicholasPeter
- Subjects
Physics::Accelerator Physics - Abstract
State-of-the-art high power laser facilities present numerous potential applications, including the generation of ultra-short and low emittance ion beams. Understanding the underlying laser-plasma interaction physics and resulting scaling to ultra-high intensities is of great importance for optimising such sources. We therefore present experimental data of proton acceleration in a sheath field using the ultra-high intensity J-KAREN-P laser (10 J, 40 fs, 5x1021 W/cm2), allowing investigation at the high-intensity frontier. A repetitive tape target was used to generate proton beams at a 0.1 Hz repetition rate limited only by the laser, allowing a systematic and comprehensive scan over laser parameters. Our laser-target system is able to regularly produce protons in excess of 40 MeV at the full repetition rate. We will demonstrate a slower than expected increase in proton energy with decreasing focal spot size, show that this is due to a reduced sheath lifetime for tight focal spots, and propose a new model which successfully predicts proton energies over a large range of focal spot sizes.We demonstrate that the laser accelerated electron temperature depends not only on laser intensity but also on focal-spot size, in which the restriction of the transverse acceleration distance causes saturation of the electron temperature at increasingly small foci. However, the accelerated electron beam profile becomes more collimated and asymmetric with small focal spots. Measurements of the proton beam show only limited benefit to using increasingly small focal spot sizes, and the best scaling for achieving higher maximum proton energies from sheath acceleration is achieved with increasing the pulse energy, rather than reducing the spot size or pulse length., Optics & Photonics International Congress 2019 (HEDS2019)
- Published
- 2019
34. Electron heating and ion acceleration in sheaths from ultra-high intensity laser-solid interactions
- Author
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Nishiuchi, Mamiko, Kevin Koga, James, Sakaki, Hironao, Kondo, Kotaro, Fukuda, Yuuji, Kiriyama, Hiromitsu, Miyahara, Takumi, Nishitani, Keita, Ogura, Koichi, Pirozhkov, Alexander, Sagisaka, Akito, Kando, Masaki, Kondo, Kiminori, and Dover, NicholasPeter
- Subjects
Physics::Accelerator Physics - Abstract
The behaviour of high power laser-plasma interaction from solid targets, and the resultant ion generation, at the extreme intensities available at state-of-the-art laser facilities is an important topic for realising potential applications. We will present experimental data investigating electron heating and proton acceleration in a sheath field using the ultra-high intensity, high contrast J- KAREN-P laser. Using a 10 J, 40 fs pulse focused to an intensity ~5x1021 Wcm-2 resulted in generation of protons up to 40 MeV at 0.1 Hz from a 5 μm steel tape target. The high repetition rate of the tape target allowed large statistically relevant investigations into the scaling of the electron and proton beam with laser energy, pulse length and spot size. We demonstrate that the laser accelerated electron temperature depends not only on laser intensity but also on focal-spot size, in which the restriction of the transverse acceleration distance causes saturation of the electron temperature at increasingly small foci. However, the accelerated electron beam profile becomes more collimated and asymmetric with small focal spots. Measurements of the proton beam show only limited benefit to using increasingly small focal spot sizes, and the best scaling for achieving higher maximum proton energies from sheath acceleration is achieved with increasing the pulse energy, rather than reducing the spot size or pulse length., Imperial College London Plasma Physics Group Seminar
- Published
- 2019
35. Ion species discrimination method by linear energy transfer measurement in Fujifilm BAS-SR Imaging Plate
- Author
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Nishiuchi, Mamiko, Sakaki, Hironao, Dover, NicholasPeter, Miyahara, Takumi, Shiokawa, Keiichiro, Manabe, Shunya, Miyatake, Tatsuhiko, Kondo, Kotaro, Kondo, Keietsu, Iwata, Yoshiyuki, Watanabe, Yukinobu, Kondo, Kiminori, Mamiko, Nishiuchi, Hironao, Sakaki, Keiichiro, Shiokawa, Tatsuhiko, Miyatake, Kotaro, Kondo, Yoshiyuki, Iwata, Yukinobu, Watanabe, and Kiminori, Kondo
- Abstract
We have developed a novel discrimination methodology to identify ions in multispecies beams with similar charge to mass ratios but different atomic numbers. After an initial separation by charge-to-mass ratio using co-linear electric and magnetic fields, individual ions can be discriminated by considering the Linear Energy Transfer and non-linear detector response of ions irradiating stimulable phosphor plate (Fujifilm imaging plate), by comparison with Monte-Carlo calculation. We apply the method to energetic multispecies laser-driven ion beams and use it to identify silver ions produced by the interaction between a high contrast, high intensity laser pulse and a sub-m silver foil target. We also show that this method can be used to calibrate imaging plate for arbitrary ion species without requiring individual calibration.
- Published
- 2020
36. Petawatt femtosecond laser pulses from titanium-doped sapphire crystal
- Author
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Kiriyama, Hiromitsu, Pirozhkov, Alexander, Nishiuchi, Mamiko, Fukuda, Yuuji, Sagisaka, Akito, Kon, Akira, Miyasaka, Yasuhiro, Ogura, Koichi, Dover, NicholasPeter, Kondo, Kotaro, Sakaki, Hironao, Kevin Koga, James, Timur, Esirkepov, HUANG, KAI, Nakanii, Nobuhiko, Kando, Masaki, Kondo, Kiminori, Bock, Stefan, Ziegler, Tim, Thomas, Püschel, Zeil, Karl, and Schramm, Ulrich
- Abstract
Ultra-high intensity femtosecond lasers have now become excellent scientific tools for the study of extreme material states in small scale laboratory settings. The invention of chirped-pulse amplification (CPA) combined with titanium-doped sapphire (Ti:sapphire) crystals have enabled realization of such lasers. The pursuit of ultra-high intensity science and applications is driving world-wide development of new capabilities. A petawatt (PW=10^15 W), femtosecond (fs=10^-15 s), repetitive (0.1 Hz), high beam quality J-KAREN-P (Japan Kansai Advanced Relativistic ENgineering Petawatt) Ti:sapphire CPA laser has been recently constructed and used for accelerating charged particles (ions and electrons) and generating coherent and incoherent ultra-short pulse, high energy photon (x-ray) radiation. Ultra-high intensities of 10^22 W/cm^2 with high temporal contrast of 10^-12 and a minimal number of pre-pulses on target has been demonstrated with the J-KAREN-P laser. Here, world-wide ultra-high intensity laser development is summarized, the output performance and spatiotemporal quality improvement of the J-KAREN-P laser are described, and some experimental results are briefly introduced.
- Published
- 2020
37. High-Intensity Laser-Driven Oxygen Source from CW Laser-Heated Titanium Tape Targets
- Author
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Kondo, Kotaro, Nishiuchi, Mamiko, Sakaki, Hironao, Dover, NicholasPeter, Lowe, HazelFrances, Miyahara, Takumi, Watanabe, Yukinobu, Ziegler, Tim, Zeil, Karl, Schramm, Ulrich, J. Ditter, Emma, S. Hicks, George, C. Ettlinger, Oliver, Najmudin, Zulfikar, Kiriyama, Hiromitsu, Kando, Masaki, Kondo, Kiminori, Kotaro, Kondo, Mamiko, Nishiuchi, Hironao, Sakaki, Yukinobu, Watanabe, Hiromitsu, Kiriyama, Masaki, Kando, and Kiminori, Kondo
- Abstract
The interaction of high-intensity laser pulses with solid targets can be used as a highly charged, energetic heavy ion source. Normally, intrinsic contaminants on the target surface suppress the performance of heavy ion acceleration from a high-intensity laser–target interaction, resulting in preferential proton acceleration. Here, we demonstrate that CW laser heating of 5 μm titanium tape targets can remove contaminant hydrocarbons in order to expose a thin oxide layer on the metal surface, ideal for the generation of energetic oxygen beams. This is demonstrated by irradiating the heated targets with a PW class high-power laser at an intensity of 5 × 10^21 W/cm2, showing enhanced acceleration of oxygen ions with a non-thermal-like distribution. Our new scheme using a CW laser-heated Ti tape target is promising for use as a moderate repetition energetic oxygen ion source for future applications.
- Published
- 2020
38. Demonstration of repetitive energetic proton generation by ultra-intense laser interaction with a tape target
- Author
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Dover, NicholasPeter, Nishiuchi, Mamiko, Sakaki, Hironao, Kondo, Kotaro, A. Alkhimova, M., Ya. Faenov, A., Hata, M., Iwata, N., Kiriyama, Hiromitsu, Kevin Koga, James, Miyahara, Takumi, A. Pikuz, T., Pirozhkov, Alexander, Sagisaka, Akito, Sentoku, Y., Watanabe, Y., Kando, Masaki, Kondo, Kiminori, Lowe, HazelFrances, J. Ditter, E., C. Ettlinger, O., S. Hicks, G., Najmudin, Z., Schramm, U., Ziegler, T., and Zeil, K.
- Abstract
High power laser systems are an attractive driver for compact energetic ion sources. We demonstrate repetitive acceleration at 0.1 Hz of proton beams up to 40 MeV from a reeled tape target irradiated by ultra-high intensities up to 5 × 1021 Wcm−2 and laser energies ≈ 15 J using the J-KAREN-P laser system. We investigate the stability of the source and its behaviour with laser spot focal size. We compare the scaling of proton energy with laser energy with a recently developed analytical model, and also demonstrate that it is possible to reach energies up to 50 MeV on a single shot with a lower laser energy ≈ 10 J by using a thinner target, motivating development of high repetition targetry suitable for thinner targets.
- Published
- 2020
39. Effect of small focus on electron heating and proton acceleration in ultra-relativistic laser-solid interactions
- Author
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Dover, NicholasPeter, Nishiuchi, Mamiko, Sakaki, Hironao, Kondo, Kotaro, A. Alkhimova, M., Ya. Faenov, A., Hata, M., Iwata, N., Kiriyama, Hiromitsu, Kevin Koga, James, Miyahara, Takumi, A. Pikuz, T., Pirozhkov, Alexander, Sagisaka, Akito, Sentoku, Y., Watanabe, Y., Kando, Masaki, Kondo, Kiminori, Mamiko, Nishiuchi, Hironao, Sakaki, Kotaro, Kondo, Hiromitsu, Kiriyama, Akito, Sagisaka, Masaki, Kando, and Kiminori, Kondo
- Subjects
Physics::Accelerator Physics - Abstract
Acceleration of particles from the interaction of ultra-intense laser pulses up to $5\times10^{21}$ Wcm$^{-2}$ with thin foils is investigated experimentally. The electron beam parameters varied with decreasing spot size, not just laser intensity, resulting in reduced temperatures and divergence. In particular, the temperature saturated due to insufficient acceleration length in the tightly focused spot. These dependencies affected the sheath-accelerated protons, which showed poorer spot-size scaling than widely used scaling laws. It is therefore shown that maximizing laser intensity by using very small focii has reducing returns for some applications.
- Published
- 2020
40. Scaling of electron heating and proton acceleration to ultra-high intensities
- Author
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Nishiuchi, Mamiko, Kevin, Koga James, Sakaki, Hironao, Kondo, Kotaro, Fukuda, Yuuji, Kiriyama, Hiromitsu, Miyahara, Takumi, Nishitani, Keita, Ogura, Koichi, Pirozhkov, Alexander, Sagisaka, Akito, Kando, Masaki, and Kondo, Kiminori
- Subjects
Physics::Accelerator Physics - Abstract
The behaviour of high power laser-plasma interaction from solid targets, and the resultant ion generation, at the extreme intensities available at state-of-the-art laser facilities is an important topic for realising potential applications. We will present experimental data investigating electron heating and proton acceleration in a sheath field using the ultra-high intensity, high contrast J- KAREN-P laser. Using a 10 J, 40 fs pulse focused to an intensity ~5x1021 Wcm-2 resulted in generation of protons up to 40 MeV at 0.1 Hz from a 5 μm steel tape target. The high repetition rate of the tape target allowed large statistically relevant investigations into the scaling of the electron and proton beam with laser energy, pulse length and spot size. We demonstrate that the laser accelerated electron temperature depends not only on laser intensity but also on focal-spot size, in which the restriction of the transverse acceleration distance causes saturation of the electron temperature at increasingly small foci. However, the accelerated electron beam profile becomes more collimated and asymmetric with small focal spots. Measurements of the proton beam show only limited benefit to using increasingly small focal spot sizes, and the best scaling for achieving higher maximum proton energies from sheath acceleration is achieved with increasing the pulse energy, rather than reducing the spot size or pulse length., AAC 2018
- Published
- 2018
41. Experimental investigation of electron heating and proton acceleration scaling to ultra-high intensity pulses
- Author
-
Kevin, Koga James, Nishiuchi, Mamiko, Sakaki, Hironao, Kondo, Kotaro, Fukuda, Yuuji, Kiriyama, Hiromitsu, Miyahara, Takumi, Nishitani, Keita, Ogura, Koichi, Pirozhkov, Alexander, Sagisaka, Akito, Kando, Masaki, and Kondo, Kiminori
- Subjects
Physics::Accelerator Physics - Abstract
The behaviour of high power laser-plasma interaction from solid targets, and the resultant ion generation, at the extreme intensities available at state-of-the-art laser facilities is an important topic for realising potential applications. We will present experimental data investigating electron heating and proton acceleration in a sheath field using the ultra-high intensity, high contrast J- KAREN-P laser. Using a 10 J, 40 fs pulse focused to an intensity ~5x1021 Wcm-2 resulted in generation of protons up to 40 MeV at 0.1 Hz from a 5 μm steel tape target. The high repetition rate of the tape target allowed large statistically relevant investigations into the scaling of the electron and proton beam with laser energy, pulse length and spot size. We demonstrate that the laser accelerated electron temperature depends not only on laser intensity but also on focal-spot size, in which the restriction of the transverse acceleration distance causes saturation of the electron temperature at increasingly small foci. However, the accelerated electron beam profile becomes more collimated and asymmetric with small focal spots. Measurements of the proton beam show only limited benefit to using increasingly small focal spot sizes, and the best scaling for achieving higher maximum proton energies from sheath acceleration is achieved with increasing the pulse energy, rather than reducing the spot size or pulse length., HEDS 2018
- Published
- 2018
42. Experimental investigation of sheath- driven proton acceleration scaling to the ultra-short pulse, ultra-high intensity regime
- Author
-
Kevin, Koga James, Nishiuchi, Mamiko, Sakaki, Hironao, Kondo, Kotaro, Fukuda, Yuuji, Kiriyama, Hiromitsu, Miyahara, Takumi, Nishitani, Keita, Ogura, Koichi, Pirozhkov, Alexander, Sagisaka, Akito, Kando, Masaki, and Kondo, Kiminori
- Subjects
Physics::Accelerator Physics - Abstract
The behaviour of high power laser-plasma interaction from solid targets, and the resultant ion generation, at the extreme intensities available at state-of-the-art laser facilities is an important topic for realising potential applications. We will present experimental data investigating electron heating and proton acceleration in a sheath field using the ultra-high intensity, high contrast J- KAREN-P laser. Using a 10 J, 40 fs pulse focused to an intensity ~5x1021 Wcm-2 resulted in generation of protons up to 40 MeV at 0.1 Hz from a 5 μm steel tape target. The high repetition rate of the tape target allowed large statistically relevant investigations into the scaling of the electron and proton beam with laser energy, pulse length and spot size. We demonstrate that the laser accelerated electron temperature depends not only on laser intensity but also on focal-spot size, in which the restriction of the transverse acceleration distance causes saturation of the electron temperature at increasingly small foci. However, the accelerated electron beam profile becomes more collimated and asymmetric with small focal spots. Measurements of the proton beam show only limited benefit to using increasingly small focal spot sizes, and the best scaling for achieving higher maximum proton energies from sheath acceleration is achieved with increasing the pulse energy, rather than reducing the spot size or pulse length., JPS butsuri gakkai
- Published
- 2018
43. 2020 roadmap on plasma accelerators.
- Author
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Albert, Félicie, Couprie, M E, Debus, Alexander, Downer, Mike C, Faure, Jérôme, Flacco, Alessandro, Gizzi, Leonida A, Grismayer, Thomas, Huebl, Axel, Joshi, Chan, Labat, M, Leemans, Wim P, Maier, Andreas R, Mangles, Stuart P D, Mason, Paul, Mathieu, François, Muggli, Patric, Nishiuchi, Mamiko, Osterhoff, Jens, and Rajeev, P P
- Subjects
PLASMA accelerators ,PARTICLE beams ,LASER pulses ,ELECTROMAGNETIC fields ,PLASMA physics ,GRADUATE students - Abstract
Plasma-based accelerators use the strong electromagnetic fields that can be supported by plasmas to accelerate charged particles to high energies. Accelerating field structures in plasma can be generated by powerful laser pulses or charged particle beams. This research field has recently transitioned from involving a few small-scale efforts to the development of national and international networks of scientists supported by substantial investment in large-scale research infrastructure. In this New Journal of Physics 2020 Plasma Accelerator Roadmap, perspectives from experts in this field provide a summary overview of the field and insights into the research needs and developments for an international audience of scientists, including graduate students and researchers entering the field. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
44. Absolute response of a Fuji BAS-TR imaging plate to low-energy protons (<0.2 MeV) and carbon ions (<1 MeV).
- Author
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Kojima, Sadaoki, Miyatake, Tatsuhiko, Inoue, Shunsuke, Dinh, Thanh Hung, Hasegawa, Noboru, Mori, Michiaki, Sakaki, Hironao, Nishiuchi, Mamiko, Dover, Nicholas P., Yamamoto, Yoichi, Sasaki, Teru, Ito, Fuyumi, Kondo, Kotaro, Yamanaka, Takashi, Hashida, Masaki, Sakabe, Shuji, Nishikino, Masaharu, and Kondo, Kiminori
- Subjects
PROTONS ,IMAGE converters ,IONS ,FUJIFILM digital cameras ,KINETIC energy ,CARBON - Abstract
This paper reports on the absolute response of a Fuji BAS-TR image plate to relatively low-energy protons (<0.2 MeV) and carbon ions (<1 MeV) accelerated by a 10-TW-class compact high-intensity laser system. A Thomson parabola spectrometer was used to discriminate between different ion species while dispersing the ions according to their kinetic energy. Ion parabolic traces were recorded using an image plate detector overlaid with a slotted CR-39 solid-state detector. The obtained response function for the protons was reasonably extrapolated from previously reported higher-ion-energy response functions. Conversely, the obtained response function for carbon ions was one order of magnitude higher than the value extrapolated from previously reported higher-ion-energy response functions. In a previous study, it was determined that if the stopping range of carbon ions is comparable to or smaller than the grain size of the phosphor, then some ions will provide all their energy to the binder resin rather than the phosphor. As a result, it is believed that the imaging plate response will be reduced. Our results show good agreement with the empirical formula of Lelasseux et al., which does not consider photo-stimulated luminescence (PSL) reduction due to the urethane resin. It was shown that the PSL reduction due to the deactivation of the urethane resin is smaller than that previously predicted. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
45. Enhancement of pre-pulse and picosecond pedestal contrast of the petawatt J-KAREN-P laser.
- Author
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Kiriyama, Hiromitsu, Miyasaka, Yasuhiro, Kon, Akira, Nishiuchi, Mamiko, Sagisaka, Akito, Sasao, Hajime, Pirozhkov, Alexander S., Fukuda, Yuji, Ogura, Koichi, Kondo, Kotaro, Dover, Nicholas P., and Kando, Masaki
- Subjects
PEDESTALS ,LASERS ,OPTICS ,ULTRASHORT laser pulses - Abstract
We have experimentally improved the temporal contrast of the petawatt J-KAREN-P laser facility. We have investigated how the generation of pre-pulses by post-pulses changes due to the temporal overlap between the stretched pulse and the post-pulse in a chirped-pulse amplification system. We have shown that the time at which the pre-pulse is generated by the post-pulse and its shape are related to the time difference between the stretched main pulse and the post-pulse. With this investigation, we have found and identified the origins of the pre-pulses and have demonstrated the removal of most pre-pulses by eliminating the post-pulse with wedged optics. We have also demonstrated the impact of stretcher optics on the picosecond pedestal. We have realized orders of magnitude enhancement of the pedestal by improving the optical quality of a key component in the stretcher. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
46. Plasma formation and target preheating by prepulse of PW laser light
- Author
-
Sentoku, Yasuhiko, Iwata, Natsumi, Kevin, Koga James, Nicholas, Dover, and Nishiuchi, Mamiko
- Abstract
An intense short pulse laser with intensity over 10^21^ W/cm^2^ has become available, i.e. J-KAREN-P at QST. Although the contrast of the short pulse is improved to be of the order of 10^−11^, there is an unavoidable prepulse, which has multiple spikes (~ ps) on top of an exponential profile with intensity greater than 10^14^ W/cm^2^ about 50 ps in front of the main pulse. The prepulse preheats the target and also produces tenuous plasmas in front of a target before the main pulse arrives. It is critical to understand such preheating of the target, where the nonlocal heat transport is essential at intensity >10^14^ W/cm^2^, since the target condition might totally change before the interaction with the main pulse. Using a hydro code, FLASH, and a collisional particle-in-cell code, PICLS, we study the preplasma formation and target preheating over tens of picoseconds timescale, and discuss the prepulse effects on the main pulse interaction., 59th Annual Meeting of the APS Division of Plasma Physics
- Published
- 2017
47. Experimental investigation of laser-driven proton sheath acceleration in the ultra-short pulse, ultra-high intensity regime
- Author
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Nishiuchi, Mamiko, Sakaki, Hironao, Kondo, Kotaro, Alkhimova, M.A., Ya., Faenov A., Fukuda, Yuuji, Hata, M., Iwata, N., Kiriyama, Hiromitsu, Kevin, Koga James, Miyahara, Takumi, Nishitani, Keita, Ogura, Koichi, Pikuz, T.A., Pirozhkov, Alexander, Sagisaka, Akito, Sentoku, Y., Watanabe, Y., Kando, Masaki, and Kondo, Kiminori
- Subjects
Physics::Plasma Physics ,Physics::Accelerator Physics - Abstract
The behaviour of high power laser driven ion generation at the extreme intensities available at state-of-the-art and next-generation laser facilities is an important topic for realising potential applications. One of the simplest schemes for proton sources for applications is sheath acceleration, for which different established models predict varying dependence on laser and target parameters, motivating experimental investigation. We will present experimental data investigating sheath driven proton acceleration using the ultra-high intensity, high contrast J-KAREN-P laser. A ~10 J, 40 fs pulse was focused to an intensity ~5x1021 Wcm-2, generating protons up to 50 MeV from freestanding ~μm foils, and up to 40 MeV at 0.1 Hz from a 5 μm tape target, with conversion efficiencies >1% into protons above 10 MeV. Scaling with different methods of laser intensity variation will be discussed. Simultaneous measurement of the electron distribution and optical probing of plasma formation on the rear target surface provide insights into electron absorption. In particular, target irradiation at 45º angle of incidence is shown to produce a systematic asymmetry in both rear surface sheath formation and resultant proton distribution due to the initial non-thermal electron distribution, causing the highest energy protons to be steered partly towards the laser axis., EAAC2017参加
- Published
- 2017
48. Towards a novel laser-driven method of exotic nuclei extraction-acceleration for fundamental physics and technology
- Author
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Nishiuchi, Mamiko, Sakaki, Hironao, Nishio, Katsuhisa, Orlandi, Riccard, Sako, Hiroyuki, Pikuz, Tatiana. A., Faenov, Anatory Ya., Esirkepov, Timur Zh., Pirozhkov, Alexander S., Matsukawa, Kenya, Sagisaka, Akito, Ogura, Koichi, Kanasaki, Masato, Kiriyama, Hiromitsu, Fukuda, Yuji, Koura, Hiroyuki, Kando, Masaki, Yamauchi, Tomoya, Watanabe, Yukinobu, Bulanov, Sergei V., Kondo, Kiminori, Imai, Kenichi, and Nagamiya, Shoji
- Subjects
Accelerator Physics (physics.acc-ph) ,Physics - Instrumentation and Detectors ,Nuclear Theory ,FOS: Physical sciences ,Physics::Accelerator Physics ,Physics - Accelerator Physics ,Instrumentation and Detectors (physics.ins-det) ,Nuclear Experiment - Abstract
The measurement of properties of exotic nuclei, essential for fundamental nuclear physics, now confronts a formidable challenge for contemporary radiofrequency accelerator technology. A promising option can be found in the combination of state-of-the-art high-intensity short pulse laser system and nuclear measurement techniques. We propose a novel Laser-driven Exotic Nuclei extraction-acceleration method (LENex): a femtosecond petawatt laser, irradiating a target bombarded by an external ion beam, extracts from the target and accelerates to few GeV highly-charged nuclear reaction products. Here a proof-of-principle experiment of LENex is presented: a few hundred-terawatt laser focused onto an aluminum foil, with a small amount of iron simulating nuclear reaction products, extracts almost fully stripped iron nuclei and accelerate them up to 0.9 GeV. Our experiments and numerical simulations show that short-lived, heavy exotic nuclei, with a much larger charge-to-mass ratio than in conventional technology, can be obtained in the form of an energetic, low-emittance, high-current beam., including supplementary information
- Published
- 2014
49. X-ray Study of Hot Plasmas in the Large Magellanic Cloud -Evolution from Supernova Remnants toward Interstellar Matter
- Author
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Nishiuchi, Mamiko
- Abstract
資料番号: SA8000171000
- Published
- 2001
50. Laser-driven Proton Accelerator for Medical Application
- Author
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Nishiuchi, Mamiko, Bolton, Paul, Hori, Toshihiko, Iseki, Yasushi, Kanazawa, Shuhei, Kiriyama, Hiromitsu, Kondo, Kiminori, Mori, Michiaki, Noda, Akira, Ogura, Koichi, Orimo, Satoshi, Pirozhkov, Alexander, Sagisaka, Akito, Sakaki, Hironao, Shirai, Toshiyuki, Souda, Hikaru, Tongu, Hiromu, Yogo, Akifumi, and Yoshiyuki, Takeshi
- Subjects
U01 Medical Applications ,Physics::Accelerator Physics ,08 Applications of Accelerators, Technology Transfer and Industrial Relations ,Accelerator Physics - Abstract
The interaction between the high intensity laser and the solid target produces a strong electrostatic proton acceleration field (1 TV/m) with extraordinary small size, contributing to downsizing of the particle accelerator. The proton beam exhibits significant features. having very small source size(~10 um), short pulse duration (~ps) and very low transverse emittance. However it is a diverging beam (half angle of ~10 deg) with wide energy spread of ~100 %. Because of these peculiar characteristics the proton beam attracts many fields for applications including medical applications. To preserve these peculiar characteristics, which are not possessed by those beams from the conventional accelerators, towards the irradiation points, we need to establish a peculiar beam transport line. As the first step, here we report the demonstration of the proto-type laser-driven proton medical accelerator beam line in which we combine the laser-driven proton source with the beam transport technique already established in the conventional accelerator for the purpose of comparison between the data and the particle transport simulation code, PARMILA*., Proceedings of the 1st International Particle Accelerator Conference, IPAC2010, Kyoto, Japan
- Published
- 2010
- Full Text
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