Project/Area Number |
14208048
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Research Category |
Grant-in-Aid for Scientific Research (A)
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Allocation Type | Single-year Grants |
Section | 一般 |
Research Field |
プラズマ理工学
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Research Institution | Osaka University |
Principal Investigator |
AZECHI Hiroshi Osaka University, Institute of Laser Engineering, Professor, レーザーエネルギー学研究センター, 教授 (90135666)
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Co-Investigator(Kenkyū-buntansha) |
SHIGEMORI Keisuke Osaka University, Institute of Laser Engineering, Associate Professor, レーザーエネルギー学研究センター, 助教授 (50335395)
SHIRAGA Hiroyuki Osaka University, Institute of Laser Engineering, Associate Professor, レーザーエネルギー学研究センター, 助教授 (90183839)
NAKAI Mitsuo Osaka University, Institute of Laser Engineering, Associate Professor, レーザーエネルギー学研究センター, 助教授 (70201663)
MIYANAGA Noriaki Osaka University, Institute of Laser Engineering, Professor, レーザーエネルギー学研究センター, 教授 (80135756)
NISHIMURA Hiroaki Osaka University, Institute of Laser Engineering, Professor, レーザーエネルギー学研究センター, 教授 (60135754)
西原 功修 大阪大学, レーザーエネルギー学研究センター, 教授 (40107131)
長友 英夫 大阪大学, レーザーエネルギー学研究センター, 助手 (10283813)
乗松 孝好 大阪大学, レーザー核融合研究センター, 教授 (50135753)
|
Project Period (FY) |
2002 – 2005
|
Project Status |
Completed (Fiscal Year 2005)
|
Budget Amount *help |
¥42,250,000 (Direct Cost: ¥32,500,000、Indirect Cost: ¥9,750,000)
Fiscal Year 2005: ¥6,240,000 (Direct Cost: ¥4,800,000、Indirect Cost: ¥1,440,000)
Fiscal Year 2004: ¥6,890,000 (Direct Cost: ¥5,300,000、Indirect Cost: ¥1,590,000)
Fiscal Year 2003: ¥8,060,000 (Direct Cost: ¥6,200,000、Indirect Cost: ¥1,860,000)
Fiscal Year 2002: ¥21,060,000 (Direct Cost: ¥16,200,000、Indirect Cost: ¥4,860,000)
|
Keywords | Rayleigh-Taylor instability / Nonlocal energy transport / Cocktail color irradiation / Double ablation / Laser fusion / 流体力学的不安定性 / 二重アブレーション / カクテルカラー照射 / 衝撃点火 / 流体力学不安定性 / 高空間分解X線イメージング / 渦 |
Research Abstract |
The concept of inertial fusion is that a spherical pellet made of fusion fuel is imploded by irradiating the surface with high power lasers, thereby assembling a high-density main fuel and a hot spark triggering thermonuclear ignition. Hydrodynamic instabilities such as the ablative Rayleigh-Taylor instability may potentially prevent the pellet from being compressed. Good understanding and suppression of the instability is, therefore, critically important for the success of inertial fusion. At the stage before starting this research project, we had found that the ablative Rayleigh-Taylor instability is significantly suppressed by nonlocal electron heat transport. The purpose of the present research is not just to accept this effect as God's breath, but to intentionally explore and establish various stabilization schemes. The schemes that we have proposed rely on nonlocal nature of thermal conduction, radiation, and convection. The present achievements are : 1.The optimum laser wavelength
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is different for nonlocal transport and for high pressure generation necessary for implosions. We propose to enhance nonlocal effect by long wavelength laser light, whereas the high pressure is generated by short wavelength laser light. We named this scheme "Cocktail Color Irradiation" and proved its favorable effect (K. Otani, to be published in Phys. Plasmas). 2.The x-ray drive of the target can also suppress the RT instability at the sacrifice of energy efficiency. We combine the suppression by x-ray radiation and the high efficient implosion by utilizing high-Z doped material as the fuel pellet itself. We named this scheme "double ablation" and proved its favorable effect (S.Fujioka, Phys.Rev.Lett. 04). 3.Vortices suppress the instability by nonlocalizing the perturbation on the unstable surface. Only this subject is still under investigation. 4.In addition to these activities, we have rigorously tested various theories of the RT instability by measuring all physical quantities appeared in the theoretical formula. As a result, we have found that long wavelength perturbations are suppressed by their nonlocality (H. Azechi, Phys.Rev.Lett. 07). Recalling 30 years activities, it is not too much to say that the understanding of the ablative Rayleigh-Taylor instability has almost reached to "the end of the game". Of course, scientific research is virtually; nonlocalization of perturbations themselves, for instance, will probably be a very interesting subject. But at the present progress of the good understanding, I believe that applying the suppression schemes on laser fusion itself is the more productive direction. Less
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