The effect of external fields and slit scattering on the beam spot profile of the coupled triplet system

Abstract

The effect of external AC magnetic fields and slit scattering on the beam spot profile of the high excitation coupled triplet focusing system has been investigated. A 2 MeV proton beam has been exposed to an AC magnetic field generated from an air-cored solenoid positioned at various positions along the beam line. The resultant increase in beam spot size due to this external field was observed to be highly dependent on the field position along the beam line, with the region encompassing the collimation apertures found to be the most sensitive to stray fields. The effects of slit scattering was more pronounced for small aperture dimensions, but overall the beam quality at these small dimensions (1 μm) was satisfactory, with only a small fraction of the beam showing energy loss. © 1995.