• F. Wang, J. Wu
  SLAC, Menlo Park, California
• Q.K. Jia, A.L. Wu
  USTC/NSRL, Hefei, Anhui

Lots of applications with mm wave need very high power (from tens of kW to MW), such as surface processing of metals and ceramics, heating magnetically confined plasma in thermonuclear fusion reactors, isotope separation and so on. Recently developed gyrotrons can provide up to 1 MW CW mm-wave source, however there are a number of limitations, needs of supper conducting magnet, cathode lifetime degradation because of very high current, almost approaching the upper limit of their power and frequency capabilities, and so on. It is thought that the electrostatic accelerator FEL (EA-FEL) will be a promising high power IR-mm source, because of its high average power generation, high-energy conversion efficiency and high spectral purity. The property of an EA as a high quality e-beam source for a FEL is crucial for attaining high brightness spontaneous emission radiation. The unique features of EA-FELs make them naturally fitting for a variety of applications in the present and in the near future. And few high power mm-IR EA FEL facilities have been successfully built around world. Here an EA of 3 MeV with beam current of 2 A is studied for a high average power (kWs) mm-THz source

• F.V. Hartemann, F. Albert, S.G. Anderson, C.P.J. Barty, A.J. Bayramian, R.E. Bonnanno, T.S. Chu, R.R. Cross, C.A. Ebbers, D.J. Gibson, T.L. Houck, R.A. Marsh, D.P. McNabb, M. J. Messerly, R.D. Scarpetti, M. Shverdin, C. Siders, S.S.Q. Wu
  LLNL, Livermore, California
• C. Adolphsen, A.E. Candel, E.N. Jongewaard, Z. Li, T.O. Raubenheimer, S.G. Tantawi, A.E. Vlieks, F. Wang, J.W. Wang, F. Zhou
  SLAC, Menlo Park, California
• V.A. Semenov
  UCB, Berkeley, California

Recent progress in accelerator physics and laser technology have enabled the development of a new class of tunable x-ray and gamma-ray light sources based on Compton scattering between a high-brightness, relativistic electron beam and a high intensity laser pulse produced via CPA. A precision, tunable, monochromatic (< 0.4%) source driven by a compact, high-gradient X-band linac designed in collaboration with SLAC is under construction at LLNL. High-brightness (250 pC, 3.5 ps, 0.4 mm.mrad), relativistic electron bunches will interact with a Joule-class, 10 ps, diode-pumped CPA laser pulse to generate tunable γ-rays in the 0.5-2.5 MeV photon energy range. This gamma-ray source will be used to excite nuclear resonance fluorescence in various isotopes. A very compact version of the accelerator (2.5 m) will also be used to generate medical x-rays in the 15-25 keV range. Fields of endeavor include homeland security, stockpile science and surveillance, nuclear fuel assay, and waste imaging and assay. The source design, key parameters, and current status will be discussed, along with important applications, including nuclear resonance fluorescence and high precision medical imaging.