Millimeter-wave photoinjector-driven chirped-pulse free-electron laser

Conference · Sun Dec 31 04:00:00 EST 1995

OSTI ID:170227

Sage, G.P. le; Fochs, S N; Feng, H X.C.; Hartemann, F V; Luhmann, Jr, N C; Heritage, J P ^[1]; Perry, M D; Westenskow, G A ^[2]

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1. Univ. of California, Davis, CA (United States)
2. Lawrence Livermore National Lab., CA (United States)

A compact, high repetition rate, relativistic photoinjector facility is currently under construction at the UC Davis Department of Applied Science, on the LLNL site. Photoelectron bunches are produced by irradiating a high quantum efficiency Cs{sub 2}Te (Cesium Telluride) photocathode with a train of 100 UV (210 nm), ultrashort (250 fs) laser pulses. These bunches are accelerated in a 1-1/2 cell {pi}-mode X-band RF structure energized by a 20 MW, 8.568 GHz SLAC klystron. The peak current is 0.25 kA (0.25 nC, 1 ps bunches), with a normalized beam emittance {var_epsilon} < 5 {pi} mm-mrad. This prebunched electron beam is then transversally accelerated in a cylindrical waveguide by a 3-mm period, 10 period long helical wiggler. The peak wiggler field is adjusted to 8.5 kG, so that the group velocity of the radiated electromagnetic waves matches the axial velocity of the electron bunch (grazing condition). Chirped output pulses in excess of 2 MW power are produced with an instantaneous bandwidth extending from 125 GHz to 225 GHz and a pulse duration of 15 ps (HWHM).

• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 170227
• Report Number(s): CONF-950612--; ISBN 0-7803-2669-5
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
DESIGN
FREE ELECTRON LASERS
LASER RADIATION
RF SYSTEMS
ULTRAVIOLET RADIATION
WIGGLER MAGNETS