| Project/Area Number |
09480109
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Nuclear fusion studies
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| Research Institution | TOKYO INSTITUTE OF TECHNOLOGY |
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Principal Investigator |
OGURI Yoshiyuki 東京工業大学, 原子炉工学研究所, 助教授 (90160829)
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| Co-Investigator(Kenkyū-buntansha) |
HATTORI Toshiyuki 東京工業大学, 原子炉工学研究所, 助教授 (50134648)
OGAWA Masao 東京工業大学, 原子炉工学研究所, 教授 (60016863)
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| Project Period (FY) |
1997 – 1998
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| Project Status |
Completed (Fiscal Year 1998)
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| Budget Amount *help |
¥1,600,000 (Direct Cost: ¥1,600,000)
Fiscal Year 1998: ¥1,600,000 (Direct Cost: ¥1,600,000)
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| Keywords | heavy ion beam / plasma / inertial fusion / stopping power / charge state / laser / Time-of-flight / spectrograph / 荷電変換 / 電子温度 |
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| Research Abstract |
We have experimentally investigated the stopping power of low-energy heavy ions in a high temperature, highly ionized plasma target. The projectile ions were delivered from a 1.7 MV tandem electrostatic accelerator. The target plasma was produced by irradiating a small LiH pellet with a Q-switched Nd glass laser. A time-of-flight system was developed for the time-resolved energy loss measurement. We found that the measured stopping power of 225 keV/u ^<16>O and 180 keV/u ^<28>Si in the plasma were larger than these in the cold neutral target by a factor of 3-4. In order to determine the effective charge of the projectile ions we measured the charge state distribution of the ^<16>O projectiles after the passage through the plasma. For this experiment we developed a broad range magnetic spectrograph with high transmission efficiency. The intensity of the charge states 4+, 5+ and 6+ were measured simultaneously by using three plastic scintillation detectors. For the plasma target, compared with the cold equivalent, the measured distribution curve shifted remarkably toward higher charge states. The most probable charge state for the cold matter is 4+, while that for the plasma target is 5+ - 6+. This experimental result shows that a low atomic number, highly ionized plasma can yield higher charge states than cold matter of the same density. This effect is principally attributable to the reduction in the number of available electron capture channels. As a result we conclude that, especially for low-velocity heavy ions, the increase in the effective charge is responsible for the large enhancement of the stopping power in the plasma target.
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