Title :
A staggered-array wiggler for far-infrared, free-electron laser operation
Author :
Huang, Y.C. ; Wang, H.C. ; Pantell, R.H. ; Feinstein, J. ; Lewellen, J.W.
Author_Institution :
Dept. of Electr. Eng., Stanford Univ., CA, USA
fDate :
5/1/1994 12:00:00 AM
Abstract :
A staggered-array wiggler for a far-infrared free-electron laser (FEL) has been built at Stanford, and its magnetic properties have been tested. This type of wiggler has several desirable features: high wiggler field at short wiggler periods, wavelength tuning by a solenoid current, electron beam confinement by a solenoid field, and looser machining tolerances. A 10.8-kilogauss peak wiggler field has been measured at a 7.0-kilogauss solenoid field for a 1.0-cm wiggler period and a 2.0-mm gap. The small-signal gain has been calculated analytically and by computer simulation for a 0.5-m long wiggler. For an 8-A, 9-ps current pulse and a 3.3-MeV electron beam, 5-dB gain is predicted. Twenty- to thirty-percent wavelength tuning can be achieved by adjusting the solenoid field and still maintain reasonable small-signal gain. The pulsed-wire technique was employed to test the field uniformity of this novel wiggler, and the measured field variation was about 1%
Keywords :
free electron lasers; laser accessories; solenoids; undulator radiation; wigglers; 0.5 m; 2 mm; 3.3 MeV; 5 dB; 7 kG; FIR FEL; Stanford; computer simulation; current pulse; electron beam confinement; far-infrared; field uniformity; free-electron laser operation; high wiggler field; looser machining tolerances; magnetic properties; pulsed-wire technique; short wiggler periods; small-signal gain; solenoid current; solenoid field; staggered-array wiggler; wavelength tuning; Electron beams; Free electron lasers; Laser tuning; Magnetic field measurement; Magnetic properties; Pulse measurements; Solenoids; Testing; Undulators; Wavelength measurement;
Journal_Title :
Quantum Electronics, IEEE Journal of
