부산대학교 도서관

Fundamental operation characteristics (a spontaneous emission spectrum and a smallsignal gain) of a low-γ, waveguide-mode free-electron laser have been measured by using a good quality relativistic photo-electron beam. Measurements are carried out at microwave frequencies (25-40 GHz) in an X-band rectangular waveguide with a low energy (450-650 keV, γ-2), low current (-1.5 A), low energy spread (ΔE/E′0-4) relativistic photoelectron beam. The spontaneous emission spectrum measured agrees well with the homogeneously broadened spectrum of a TE10 waveguide mode. The small-signal gain spectrum measured is in good agreement with theoretical prediction calculated by assuming the operation in the low-gain Compton regime.