Using channeling in a 5-mm crystal with bending angle of 0.65 mrad, a record high efficiency, over 60%, of particle extraction from accelerator was achieved. The extracted beam intensity was up to 5.2*10^11 protons per spill of 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.
@article{arxiv.hep-ex/0111028,
title = {New projects of crystal extraction at IHEP 70-GeV accelerator},
author = {A. G. Afonin and V. M. Biryukov and V. N. Chepegin and Yu. A. Chesnokov and V. I. Kotov and V. I. Terekhov and E. F. Troyanov and Yu. S. Fedotov and Yu. M. Ivanov and W. Scandale and M. B. H. Breese},
journal= {arXiv preprint arXiv:hep-ex/0111028},
year = {2007}
}