Accession Number : ADA130149

Title :   Beam Breakup Instabilities in High Current Electron Beam Racetrack Induction Accelerators,


Personal Author(s) : Godfrey,Brendan B ; Hughes,Thomas P

PDF Url : ADA130149

Report Date : 22 Apr 1983

Pagination or Media Count : 33

Abstract : Beam breakup and negative mass instability growth rates for a 1 kA, 40 MeV electron beam racetrack induction accelerator are computed. The device is taken to have four accleration gaps, each with 0.2 MeV applied voltage and 15 ohm transverse impedence; the guide field is 2 kg. We find that the total amplification of the beam breakup mode is limited to five e-findings provided that the cavity mode quality factor Q is 6. Thus, the negative mass instability, which grows several times faster, is the dominant consideration. However, we also find that they energy range over which the negative mass instability occurs can be narrowed substantially by reducing the guide field strength after the beam has been accelerated to about 12 MeV. This approach, coupled with beam thermal effects, not considerated here, probably is sufficient to limit negative mass growth to acceptable levels in tge racetrack accelerator. (Author)

Descriptors :   *Electron beams, *High power, *Induction systems, *Acceleration, Growth(General), Rates, Flash radiography, Photography, Mass, Stability, Geometry, Magnetic fields

Subject Categories : Test Facilities, Equipment and Methods
      Particle Accelerators

Distribution Statement : APPROVED FOR PUBLIC RELEASE