Abstract： For a long pulse free-electron laser (FEL) in the low gain regime, an approximate expression is given to describe the optical field gain from the small signal to the weak saturation. The result is shown to agree with those from a 1-D computer simulation.
JIA Qika. AN ANALYTICAL CALCULATION FOR THE LASER GAIN IN A LONG PULSE FREE-ELECTRON LASER
[J]. 中国物理快报, 1989, 6(12): 533-536.
JIA Qika. AN ANALYTICAL CALCULATION FOR THE LASER GAIN IN A LONG PULSE FREE-ELECTRON LASER
. Chin. Phys. Lett., 1989, 6(12): 533-536.
1989, Vol. 6 
