V.N. Litvinenko, S.H. Park *, I.V. Pinayev, Y. Wu **
FEL Laboratory, Duke University, NC, * KAERI, Korea, ** LBNL, Berkeley, CA
In this paper we present results of our experimental and theoretical studies of both average and peak power limitations in the OK-4/Duke storage ring FEL. Our theoretical studies are based on the 3D FEL macro-particle model which include local interactions, heating and spontaneous radiation. The OK-4/Duke storage ring FEL is operational since 1996 and demonstrated lasing in wavelength range from 193 nm to 730 nm using electron beam energies from 220 to 800 MeV. It operated in both CW and the giant pulse modes. During this period of time we collected substantial amount of data regarding the FEL power and electron beam dynamics. We compare the results with our rigorous theoretical predictions based on the exact numerical model [1]. We also discuss a number of simplified scaling lows for the FEL gain and power as functions electron beam energy and current, as well as, the cavity losses. A number of our conclusions are drastically different from those published by other storage ring FEL groups. We discuss possible reasons for these differences.
[1] V.N. Litvinenko et al, NIM A 358 (1995) pp.334-337, pp.369-373
