New projects of crystal extraction at IHEP 70 GeV accelerator

Abstract

Using channeling in a 5-mm crystal with bending angle of 0.65 mrad, a record high efficiency, over 60%, of particle extraction from the accelerator was achieved. The extracted beam intensity was up to 5.2/spl times/10/sup 11/ protons per spill of /spl sim/0.5 s duration. Also, the first proof-of-principle experiment on 'crystal collimation' was performed where crystal-serving as a scraper-has reduced the radiation level in the accelerator by a factor of two. The measurements agree with Monte Carlo predictions.