Photoinjector-driven chirped-pulse free-electron maser

Conference · Wed Nov 01 04:00:00 EST 1995

OSTI ID:116399

Hartemann, F V; Le Sage, G P; Fochs, S N; Feng, H X.C.; Laurent, L; Rosenau, S A; Luhmann, Jr, N C ^[1]

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1. Univ. of California, Davis, CA (United States). Dept. of Applied Science

A compact, high repetition rate (2.142 GHz in burst mode), relativistic (5 MeV) 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 photocathode with a train of 100 UV (210 mn), 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 emittance {epsilon} < 2.5 {pi} mm-mrad. This prebunched electron beam is then transversally accelerated in a cylindrical waveguide by a 30-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 pulses in excess of 2 MW power are produced with an instantaneous bandwidth extending from 125 GHz to 225 GHz, and pulse duration of 15 ps.

• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 116399
• Report Number(s): CONF-950793--; ISBN 0-8194-1916-8
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
BEAM BUNCHING
BEAM EMITTANCE
DESIGN
FREE ELECTRON LASERS
LAWRENCE LIVERMORE NATIONAL LABORATORY
MASERS
RF SYSTEMS
WIGGLER MAGNETS