New projects of crystal extraction at IHEP 70-GeV accelerator

TL;DR

This paper reports on new crystal extraction projects at IHEP's 70-GeV accelerator, achieving record efficiency and demonstrating crystal collimation to reduce radiation, with results aligning with simulations.

Contribution

It introduces high-efficiency crystal extraction and first proof-of-principle crystal collimation experiments at the 70-GeV accelerator.

Findings

Particle extraction efficiency over 60% achieved.

Beam intensity up to 5.2×10^11 protons per spill.

Radiation level reduced by a factor of two using crystal collimation.

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 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.