Studies of the Integer Cyclotron Resonances in a Modified Betatron Accelerator
Abstract
This paper briefly summarizes recent experimental results from the studies of the integer cyclotron resonances in the NRL modified betatron accelerator. Special emphasis is given to the l = 12 resonance, because the NRL device has a twelve-fold symmetry. To test the importance of the l = 12 resonance, we have intentionally introduced an l = 12 field error using twelve resonant coils. By activating these coils when the resonance is observed, the duration of x-rays produced by beam loss was reduced from 900 microsecond to 5.5 microsecond, while the amplitude of the signal increased from 0.5 to about 40 volts. The full width of the x-ray pulse at half maximum is inversely proportional to the current through the resonant coils and proportional to the risetime of the pulse. Work is in progress with a set of twelve internal coils that have a risetime of 300-400 ns. Studies of the spatial distribution of beam losses at l = 12 show that the beam is always lost in six well defined toroidal positions. In addition, it has been shown experimentally that when the ratio of the total toroidal magnetic field to the vertical field is not an integer, the cyclotron resonance is not excited.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 28, 1992
- Accession Number
- ADA253460
Entities
People
- Chris A. Kapetanakos
- J. H. Chang
Organizations
- United States Naval Research Laboratory