|Budget Amount *help
¥2,500,000 (Direct Cost : ¥2,500,000)
Fiscal Year 1998 : ¥200,000 (Direct Cost : ¥200,000)
Fiscal Year 1997 : ¥2,100,000 (Direct Cost : ¥2,100,000)
Fiscal Year 1996 : ¥200,000 (Direct Cost : ¥200,000)
A broad band microwave compact FEL oscillator was studied for the purpose of operating in general laboratory for scientific research(electric supply 3phi 220V/3 lines). The results obtained are as follows.
(1)Development of a helical wiggler in solenoid induced structure. It becomes clear that the wiggler fields Bw with planar and helical stmcture have comparative values as decreasing the wiggler periods lambdaw, and we obtained an useful helical wiggler for FEL experiment using low energy electron beam less than I MeV needed for strong guiding field Bo.
(2)Design of electron beam system. After considering the power supply of thermal cathode set out or in the vacuum chamber, finally, we adopted a 1.aB6 cathode heating by CO_2 laser, It was realized owing to taking a 70 W CO_2 laser equipment in our laboratory. The electron gun is designed by E-gun code, and it can be propagated an focusing electron beam to a drift tube through the accelerating voltage 10-100kV and current of Io=10mA.
(3) Analysis of FEL operation. In case of lambdaw=I6mm, Bw=250G, Bo=3kG, the variety of electron beam energy Eo=111-200keV gives variety of oscillation frequency 15.4-37.2GHz(wavelength 19.5-8.1mm). Further, in case of Eo=l20keV and Io=5OmA(beam power 6kW) and wiggler period number is 30, the saturation output is 50W, and small signal gain is 0.4%.
From the results mentioned above, the fundamental data and technology needed for our purpose of the broad band microwave compact FEL oscillator was established. Hereafter, we want to construct the FEL oscillator and to obtain the experimental data in FEL operation.