Title :
A Hybrid Magnetic Focusing System for Microwave Tubes
Author :
Périgo, Elio A. ; Barroso, Joaquim J. ; Motta, Cláudio C.
Author_Institution :
Nucl. & Energetic Res. Inst., Sao Paulo
Abstract :
By using a three-dimensional particle-in-cell code, this paper reports on the electron-beam propagation behavior in a drift tube under two situations. First, it investigated the influence of the acceleration potential on the beam trajectory when using a periodic permanent magnet (PPM) focusing structure upon keeping constant either the electric current or the beam perveance. Next, taking for granted the optimum focalization parameters found in the previous evaluation, it examined the feasibility of using a hybrid magnetic focusing system (HS)-a PPM array clamped at the ends by a pair of solenoids-so that the value of the magnetic flux density at the entrance to the PPM system satisfies the Brillouin field condition. An experimental setup of the HS using PPM NdFeB permanent magnets without pole pieces is also reported
Keywords :
electron beams; microwave tubes; particle beam dynamics; particle beam focusing; permanent magnets; Brillouin field; acceleration potential; beam perveance; beam trajectory; drift tube; electric current; electron-beam propagation; hybrid magnetic focusing; magnetic flux density; microwave tubes; particle-in-cell code; periodic permanent magnet; solenoids; Acceleration; Electron beams; Electron tubes; Magnetic confinement; Magnetic flux; Magnetic flux density; Microwave propagation; Particle beams; Permanent magnets; Solenoids; Hybrid magnetic focusing system (HS); particle-in-cell (PIC) code; periodic magnetic focusing; traveling-wave tubes;
Journal_Title :
Plasma Science, IEEE Transactions on
DOI :
10.1109/TPS.2006.881888