Title :
Dynamics of the space-charge-limiting current in gyro-type devices
Author :
Spencer, Thomas A. ; Hendricks, Kyle J. ; Luginsland, John W. ; Stump, Mark D.
Author_Institution :
Res. Lab., Kirtland AFB, NM, USA
fDate :
6/1/1998 12:00:00 AM
Abstract :
The Air Force Research Laboratory is investigating the dynamic interactions which occur between the growing electromagnetic waves generated in a gyro-type device, and an electron beam (e-beam) with nonzero perpendicular velocity operating near the space-charge-limiting current. Particle-in-cell (PIC) codes are used to perform simulations of the transverse electric (TE)01 mode, and results are presented. Initial results show that beams of this nature suffer from a time-dynamic onset of the space-charge-limiting current instability at values below those predicted from analytic theory. This produces a beam time-dynamic pulse shortening, thus placing an upper limit on the power and pulse length of gyro-type devices
Keywords :
backward wave oscillators; electron beams; gyrotrons; microwave generation; microwave tubes; space-charge limited devices; Air Force Research Laboratory; dynamic interactions; electron beam; growing electromagnetic waves; gyro-BWO; gyro-type device; gyro-type devices; nonzero perpendicular velocity; particle-in-cell codes; power; pulse length; space-charge-limiting current; space-charge-limiting current instability; time-dynamic onset; time-dynamic pulse shortening; transverse electric (TE)01 mode; upper limit; Cathodes; Computer simulation; Cutoff frequency; Cyclotrons; Electromagnetic scattering; Electron beams; Gyrotrons; Laboratories; Microwave devices; Tellurium;
Journal_Title :
Plasma Science, IEEE Transactions on
