COHERENT ELECTROMAGNETIC EFFECTS IN HIGH CURRENT PARTICLE ACCELERATORS. III. ELECTROMAGNETIC COUPLING INSTABILITIES IN A COASTING BEAM

Journal Article · Wed Mar 01 04:00:00 EST 1961 · Rev. Sci. Instr.

DOI:https://doi.org/10.1063/1.1717342· OSTI ID:4056367

Laslett, L J

The electromagnetic interaction of an intense relativistic coasting beam with itself, including the effect of a nonperfectly conducing vacuum tank, or a quiescent r-f cavity,k is investigated theoretically. It is shown that the resonances that may occur between harmonics of the particle circulation frequencies and the electromagnetic modes of the cavities can lead to a longitudinal instability of the beam. A criterion for stability of the beam against such longitudinal bunching is obtained as a restriction on the shunt impedance of the r-f cavity, or the Q of the vacuum tank. This criterion contains the energy spread and intensity of the coasting beam, as well as the parameters of the accelerator. Numerical examples are given which indicate that, in general, the resonances with the vacuum tank will not cause instabilities, while those with an r-f cavity can be prevented from causing instabilities by choosing the shunt impedance at a sufficiently low but still convenient value. (auth)

• Research Organization: University of California, Lawrence Radiation Laboratory, Berkeley, CA (US)
• Sponsoring Organization: US Atomic Energy Commission (AEC)
• DOE Contract Number: W-7405-ENG-48
• NSA Number: NSA-15-015116
• OSTI ID: 4056367
• Report Number(s): UCRL-9328
• Journal Information: Rev. Sci. Instr., Journal Name: Rev. Sci. Instr. Vol. Vol: 32
• Country of Publication: United States
• Language: English

Related Subjects

ACCELERATORS
BEAMS
CIRCUITS
CURRENTS
DISTRIBUTION
ELECTRIC CONDUCTIVITY
ELECTROMAGNETIC FIELDS
ELECTROMAGNETISM
ENERGY
FREQUENCY
INTERACTIONS
NUMERICALS
PHYSICS
Q-VALUE
RADIO WAVES
RELATIVITY THEORY
RESONANCE
STABILITY
VACUUM
VESSELS