2000 Fiscal Year Final Research Report Summary
Experimental Observation of Cyclotron Superradiance from an Intense Relativistic Electron Beam.
| Project/Area Number |
11680480
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
プラズマ理工学
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| Research Institution | Kanzawa University |
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Principal Investigator |
KAMADA Keiichi Kanazawa University, Department of Physics, Assistant Professor., 理学部, 助教授 (90143875)
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| Co-Investigator(Kenkyū-buntansha) |
ANDO Ritoku Kanazawa University, Department of Physics, Assistant Professor., 理学部, 助教授 (80212679)
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| Project Period (FY) |
1999 – 2000
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| Keywords | intense relativistic electron beam / autoacceleration / superradiance / high-power millimeter wave source / electron cyclotron maser |
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| Research Abstract |
An ultrashort pulsed high power electron beam with width of 1 ns and energy of 1.1 MeV was obtained from an intense relativistic electron beam with width of 10 ns and energy of 0.55 MeV using 4-stage autoacceleration.
The ultrashort pulsed electron beam with width of 1 ns was injected into a cylindrical waveguide immersed in a uniform magnetic field. Intense radiated microwaves with narrow frequency spectrum were observed when the group velocity of the electromagnetic wave coincided with the beam electron velocity, while, the microwave spectrum with the beam with width of 10 ns showed many surplus peaks. The particle simulation code KARAT also indicated that the beam width affected the radiation spectrum.
The length of the drift tubes where the beam electrons interacted with the electromagnetic waves was changes. The output power of the radiated microwave increased exponentially with 1 ns and 10 ns beams. The output power of the microwave from 1 ns beam increased more rapidly than that from 10 ns beam. However, that saturated at the length of 40 cm. After 60 cm propagation, the output power from the 1 ns beam was 10 times larger than that from 10 ns beam.
These results suggest that the cyclotron superradiance was observed in the experiment. The dependence of the output power on the beam current should be investigated.
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