1997 Fiscal Year Final Research Report Summary
Investigation on Direct Energy Conversion for Helium-3 Fuelled Nuclear Fusion
| Project/Area Number |
08558052
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| Research Category |
Grant-in-Aid for Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Section | 展開研究 |
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| Research Field |
Nuclear fusion studies
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| Research Institution | KYOTO UNIVERSITY |
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Principal Investigator |
YASAKA Yasuyoshi Kyoto Univ., Grad.School of Eng., Assoc.Professor, 工学研究科, 助教授 (30109037)
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| Co-Investigator(Kenkyū-buntansha) |
MOMOTA Hiromu National Institute for Fusion Science, Professor, 核融合科学研究所, 教授 (10023714)
KUBO Makoto Kyoto Univ., Grad.School of Eng., Instructor, 工学研究科, 助手 (80089127)
ISHIKAWA Motoo Kyoto Univ., Grad.School of Eng., Assoc.Professor, 工学研究科, 助教授 (90109067)
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| Project Period (FY) |
1996 – 1997
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| Keywords | nuclear fusion / helium 3 / direct energy conversion / proton beam / RF traveling wave |
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| Research Abstract |
We perform a proof-of-principle experiment of a traveling wave direct energy converter (TWDEC), which was proposed as an efficient energy converter from high-energy protons produced by D-^3-He fueled fusion reactor directly into electricity. In TWDEC,the incident proton beam is velocity-modulated so as to form a bunched beam, which is to be decelerated by a traveling RF wave. The induced current in the traveling wave circuit provides RF power to the load.
We use low-energy He-ion beam of a few keV and investigate the interaction of the beam with RF for modulation and deceleration. The experimental apparatus consists of a helicon-wave ion source, a modulator and a decelerator. The He-ion beam is velocity-modulated with RF electric fields at 7MHz applied to the two modulator grids. The decelerator grids (4 to 8) are aligned along the beam path with each separation of a few cm. They are connected to a transmission line terminated with a matched load resistor. We drive the transmission line by the same RF source for the modulator with a variable phase difference. We confirm that the beam is first velocity modulated at the modulator and then, density-modulated as a result of bunching. We compare the energy distribution functions of the beam with and without the driving voltage on the transmission line to find that the distribution function shifts toward lower energy side upon application of the modulator and decelerator RF.When the phase of the decelerator RF with respect to the modulator RF is changed by pi, the high energy component is increased. These results indicate that the ion beam can be decelerated by the traveling wave as planned in TWDEC concept. The efficiency of deceleration of the beam is measured to be 14%, which is consistent with simulation results.
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