LONGITUDINAL RESISTIVE INSTABILITIES OF INTENSE COASTING BEAMS IN PARTICLE ACCELERATORS

Journal Article · Tue Sep 29 04:00:00 EDT 1964 · Review of Scientific Instruments

OSTI ID:939099

Neil, V Kelvin; Sessler, Andrew M

The effect of finite resistance in the vacuum-tank walls on the longitudinal stability of an intense beam of particles in an accelerator is investigated theoretically. We show that even if the particle frequency is an increasing function of particle energy, the wall resistance can render the beam unstable against longitudinal bunching. In the absence of frequency spread in the unperturbed beam, the instability occurs with a growth rate that is proportional to (N/{sigma}){sup 1/2}, where N is the number of particles in the beam and {sigma} is the conductivity of the surface material. By means of the Vlasov equation a criterion for beam stability is obtained. In the limit of highly conducting walls the criterion involves the frequency spread in the unperturbed beam, the number of particles N, the beam energy, geometrical properties of the accelerator, but not the conductivity {sigma}. A numerical example presented indicates that certain observations of beam behavior in the MURA 40-Mev-electron accelerator may be related to the phenomenon we investigated.

• Research Organization: Ernest Orlando Lawrence Berkeley National Laboratory, Berkeley, CA (US)
• Sponsoring Organization: Accelerator& Fusion Research Division
• OSTI ID: 939099
• Report Number(s): UCRL-11089-Rev
• Journal Information: Review of Scientific Instruments, Journal Name: Review of Scientific Instruments; ISSN 0034-6748; ISSN RSINAK
• Country of Publication: United States
• Language: English

Related Subjects

99 GENERAL AND MISCELLANEOUS
ACCELERATORS
BOLTZMANN-VLASOV EQUATION
INSTABILITY
STABILITY