Title :
PIC code simulation of pulsed radiation in a tapered closed-cavity gyrotron
Author :
Wu, Hao ; Liou, RongLin ; McCurdy, Alan H.
Author_Institution :
Dept. of Electr. Eng.-Electrophys., Univ. of Southern California, Los Angeles, CA, USA
fDate :
6/1/1996 12:00:00 AM
Abstract :
MAGIC, a two-and-one-half-dimensional particle-in-cell (PIC) code, has been used to investigate mode locking in closed-cavity gyrotrons. A cavity, with equally spaced modal frequencies, composed of a radially tapered section and a straight section of waveguide, is designed, built, and cold-tested. Experimental cold test results agree well with the MAGIC PIC code simulations. Using a sinusoidal current density modulation with an amplitude of 5% of the dc current and frequency of 280 MHz, the simulation results show radiation output in a train of narrow pulses (full width at half maximum ~1 us) at a 280 MHz repetition rate. Though the gyrotron does not appear to be mode locked, uniform pulse trains of 30-50 pulses can be obtained
Keywords :
cavity resonators; current density; gyrotrons; simulation; 280 MHz; MAGIC; PIC code simulation; experimental cold test results; mode locking; pulsed radiation; sinusoidal current density modulation; tapered closed-cavity gyrotron; two-and-one-half-dimensional particle-in-cell code; uniform pulse trains; waveguide; Amplitude modulation; Electromagnetic waveguides; Electron beams; Frequency; Gyrotrons; Laser mode locking; Masers; Microwave oscillators; Pulse width modulation; Testing;
Journal_Title :
Plasma Science, IEEE Transactions on
