Versatile H/sup +/ beam chopper system at LAMPF

Conference · Mon Jan 01 04:00:00 EST 1979

OSTI ID:6316678

Lunsford, J S; Lawrence, G P; Bentley, R F

The H/sup +/ chopper system at LAMPF provides two modes (A and B) of beam chopping. Mode A provides single micropulses separated by 1 ..mu..s or more. Mode B provides a single pulse 50-ns to 10-..mu..s long at the LAMPF repetition rate of 12 Hz. The mode of operation is selected with coaxial relays which can switch during the dead time between LAMPF macropulses. The chopper consists of 1-m-long push-pull helical-wound slow-wave deflecting structures having an axial pulse velocity of 0.04c, which matches the velocity of the proton beam. The helix ground-planes are biased by a pulser providing push-pull 500-V pulses to deflect the H/sup +/ beam from the injection channel. In chopping mode A, the helical windings are driven by push-pull, 1000-V, 5-ns pulses delivered by a circuit utilizing avalanche transistors and planar triodes. In mode B, the helical windings are driven by push-pull, 1000-V, 50-ns to 10-..mu..s long pulses, produced by a circuit utilizing beam-power tetrodes and fast SCRs. In both modes, these pulses cancel the ground-plane bias and permit beam pulses to be delivered to the linac.

• Research Organization: Los Alamos Scientific Lab., NM (USA)
• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 6316678
• Report Number(s): LA-UR-79-708; CONF-790327-28
• Country of Publication: United States
• Language: English

Related Subjects

43 PARTICLE ACCELERATORS
430200 -- Particle Accelerators-- Beam Dynamics
Field Calculations
& Ion Optics
430303* -- Particle Accelerators-- Experimental Facilities & Equipment
ACCELERATORS
BEAM PULSERS
BEAMS
CONFIGURATION
HELICAL CONFIGURATION
LAMPF LINAC
LINEAR ACCELERATORS
MESON FACTORIES
NUCLEON BEAMS
PARTICLE BEAMS
PERFORMANCE
PROTON BEAMS
PULSE TECHNIQUES