@misc{oai:repo.qst.go.jp:00083911,
 author = {南, 卓海 and 廖, 育資 and 境, 健太郎 and 西本, 貴博 and 安部, 勇輝 and 桐山, 博光 and 近藤, 康太郎 and 有川, 安信 and 余語, 覚文 and 坂和, 洋一 and Morace, Alessio and 江頭, 俊輔 and 太田, 雅人 and 浅井, 孝文 and 神野, 智史 and 金崎, 真聡 and 福田, 祐仁 and 羽原, 英明 and 溫, 偉源 and 蔵満, 康浩 and Hiromitsu, Kiriyama and Kotaro, Kondo and Takafumi, Asai and Yuji, Fukuda},
 month = {Nov},
 note = {Laser ion acceleration has been intensively inves- tigated after the development of chirped pulse am- plification (CPA) technique. The accelerated ions are applicable for cancer therapy, radioisotope pro- duction, and fast ignition for inertial confinement fusion. To achieve higher ion energies, target thick- ness should be reduced. However, thinner targets can be easily broken by the pedestal or prepulse be- fore the main pulse arrival. We have developed a large-area suspend graphene (LSG) target, which is a single to multiple layered freestanding graphene sheet[3]. Graphene is the thinnest and the strongest material, hence LSG has the potential to be the best targets of laser ion acceleration.
We have conducted several experiments with LFEX laser in Osaka University and J-KAREN-P laser in Kansai Photon Science Institute, National Institutes of Quantum Science and Technology. The LFEX laser irradiates on LSG targets with target normal angle. The maximum intensity is ∼ 4 × 10^18 W/cm^2. The J-KAREN-P laser is focused on LSG targets with 45 degree of incident angle at the intensity of ∼ 5 × 10^21 W/cm^2. We have tested the irradiation of non-relativistic laser inten- sity, < 10^18 W/cm^2, by putting the targets at defocusing positions of J-KAREN-P. Thomson parabola spectrometer and CR-39 stack are used to diagnose the accelerated ions. In the all experiments, no plasma mirrors are used.
We have observed energetic ions with relativistic laser intensities, a0 ∼ 48 of J-KAREN-P best focus shots and a0 ∼ 1.8 of LFEX. Furthermore, MeV energy ions are also observed with non-relativistic laser intensity, a0 < 1, in defocused experiments of J-KAREN-P. These results imply that LSG has special features no other materials have. We discuss these specialities using particle-in-cell simulations., 第38回 プラズマ・核融合学会 年会},
 title = {非相対論から相対論的強度のレーザーによるナノメートル厚ターゲットlarge-area suspended grapheneを用いたイオン加速},
 year = {2021}
}