| Project/Area Number |
06680440
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
プラズマ理工学
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| Research Institution | Niigata University |
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Principal Investigator |
OGURA Kazuo Niigata University, Associate Professor, 工学部, 助教授 (40214093)
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| Co-Investigator(Kenkyū-buntansha) |
CHO Teruji University of Tsukuba, Professor, 物理学系, 教授 (80171958)
MINAMI Kazuo Niigata University, Professor, 工学部, 教授 (00023135)
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| Project Period (FY) |
1994 – 1995
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| Project Status |
Completed (Fiscal Year 1995)
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| Budget Amount *help |
¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 1995: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1994: ¥1,400,000 (Direct Cost: ¥1,400,000)
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| Keywords | Backward Wave Oscillator / Plasma / Electron Beam / Distribution Function / Cherenkov Oscillation / Slow Cyclotron Maser / X-ray Diagnostics / Bremsstrahlung |
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| Research Abstract |
X-ray radiated by an intense electron beam is measured in order to study an electron beam distribution function in backward wave oscillators. Since the radiation is Bremsstrahlung for collisions between beam electrons and plasma ions, the X-ray measurements are performed with the plasmas loaded backward wave oscillators.
First, in order to find a suitable electron beam for the X-ray diagnostics, the generation and propagation of intense electron beams for the backward wave oscillator are investigated.
Second, the relationship between the beam parameters and the operation modes of the backward wave oscillators is studied. There are two main operation modes, these are conventional Cherenkov oscillation and slow cyclotron maser. The latter is a new mechanism which is proposed and demonstrated for the first time. The plasma increases the oscillation efficiency of the backward wave oscillators by an amount from several to ten times. This plasma effect is observed for the two operation modes of backward wave oscillators.
Finally, X-ray detecting system using silicon surface barrier diodes is prepared. Analyzing code used takes into account the X-ray response of the detector and the angular dependence of Bremsstrahlung. According to our X-ray diagnostics, intense electron brams produce plasma with a few keV energy, which is not contribute the currents. The beam energy distribution is relatively broad, might be an plateau like, not Maxwellian or delta function like.
For the study of the relationships between the beam distribution function and the operation mechanism of backward wave oscillators, we plan to increase the accuracy of X-ray diagnostics and perform the systematic X-ray measurements.
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