(WE-1-02) Presenting Author: Nobuyuki Nishimori
Free Electron Laser Laboratory, Japan Atomic Energy Research Institute
m
was obtained at JAERI-FEL.
The FEL energy per micropulse reached to 160 J.
The extraction efficiency from electron beam to laser radiation power
measured by an energy analyzer
was 4.6 % and the wavelength spread was 4.6 % (rms) at maximum FEL
outcoupling.
The extraction efficiency in general has maximum value
near the perfect synchronism
of cavity-length detuning, where the single-pass gain becomes
smallest to the contrary.
Large peak current and long duration of macropulse are, therefore,
indispensable to realize lasing with such high efficiency.
The electron beam energy was 16.4 MeV and average beam current was 5.4 mA
at 10.4125 MHz micropulse repetition rate.
The macropulse duration was 500 s (5000 micropulses) long enough to reach
saturation near the perfect synchronism.
The micropulse width was 5 ps (FWHM) with peak current of 100 A
in the undulator.
We will present the results of our high power FEL experiments.