Mev x-ray and position generation by ultra intense lasers

超强激光产生兆电子伏 X 射线和位置

• 批准号: 07458247
• 负责人: MIMA Kunioki
• 金额: $ 0.7万
• 依托单位: Osaka University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 1995
• 资助国家: 日本
• 起止时间: 1995 至 1997
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07458247/
• 关键词: ultra intense laser; MeV x-ray; positron; two stream instability; Weibal Instability; computer simuration; relativistic plasma; active galaxy; 高エネルギー電子; 2次元粒子シミュレーション; X線スペクトル; 自己収束; 制動放射; 偏光; 粒子シミュレーション; 電子加速; ポンディラモ-ティブ力; 衝撃波; エネルギースペク

Investigated are the interactions of short pulse ultra intense lasers with solid targets by a particle in cell computer simulation code and theoretical analysis. MeV x-ray spectra from relativistic plasmas are also investigated by using the laser facilities which are installed in the institute. In the computer simulation, we clarified that with 10^<18>-10^<19>w/cm^2 irradiation intensity, laser produced plasmas on solid targets emit a few MeV electrons and ions. We also found that the energy spectrum of those high energy electron reaches several 10 MeV when the laser intensity is higher than 10^<19>w/cm^2.The simulations show also that ultra strong magnetic field higher than 10^9 Gauss is generated. As for the generation mechanism of this strong magnetic field, it is found that the mechanism is closely related to the two stream instabilities (or Weibel instability). The generation of strong magnetic field effects the MeV x-ray and positron generations.The two dimensional simulation was also developed and used for studying the electro-magnetic phenomena around focused intense laser spot. By those simulations, high energy electron relaxation in dense plasmas, MeV x-ray reneration and electron-positron pair creation are investigated. The results are compared with recent experimental results to find future research issues.Finally, we realized that the above results will be useful for understanding the relativistic plasma phenomena near active galactic nuclear.

研究了短脉冲超强激光与固体目标的相互作用，并进行了数值模拟和理论分析。利用研究所安装的激光设备，研究了相对论等离子体的MeV x射线光谱。在计算机模拟中，我们澄清了在10^<18>-10^<19>w/cm^2的辐照强度下，激光产生的等离子体在固体目标上发射出几个MeV的电子和离子。我们还发现，当激光强度大于10^<19>w/cm^2时，这些高能电子的能谱达到了几个10 MeV。模拟结果还表明，产生了大于10^9高斯的超强磁场。对于这种强磁场的产生机理，发现其机理与两流不稳定性（或称Weibel不稳定性）密切相关。强磁场的产生影响了MeV x射线和正电子的产生。建立了二维模拟方法，并将其用于研究聚焦强激光光斑周围的电磁现象。通过这些模拟，研究了密集等离子体中的高能电子弛豫、MeV x射线再生和电子-正电子对的产生。并将所得结果与近期的实验结果进行对比，找出未来的研究方向。最后，我们意识到上述结果将有助于理解活动星系核附近的相对论性等离子体现象。

项目成果

K.Mima etal: "Interaction Physics of the Fast Ignition Concept" Phys.Rev.Letters. Vol.77,No.12. 2483-2486 (1996)

K.Mima 等人：“快速点火概念的相互作用物理学”Phys.Rev.Letters。

K.Mima, et al.: "Interaction Physics of the Fast Ignition Concept" Phys.Rev.Letters. Vol.77 No.12. 2483-2486 (1996)

K.Mima 等人：“快速点火概念的相互作用物理学”Phys.Rev.Letters。

K.Mima, et al.: "Simulation Study of the Multi-Species Ion Plasma Interacting with on Ultra Intense Laser" Journal of Plasma and Fusion Research. Vol.73 No.3. 343-349 (1998)

K.Mima 等人：“多物种离子等离子体与超强激光相互作用的模拟研究”等离子体与聚变研究杂志。

三間 圀興: "レーザーと慣性核融合研究の新展開" 学術月報. Vol.51,No.2. 138-141 (1998)

Kunioki Mima：“激光和惯性聚变研究的新进展”学术月报第51卷，第138-141期（1998）。

三間圀興: "レーザーと慣性核融合研究の新展開" 学術月報. Vol.51,No.2. 138-141 (1998)

Kuniyuki Mima：“激光与惯性聚变研究的新进展”学术月刊报告第51卷，第138-141期（1998）。