Progress in study of efficient crystal extraction and collimation at IHEP

摘要

The radical efficiency increase of accelerator beam extraction by means of bent crystals is reached by reducing the longitudinal dimension and bending angle of crystals. The usage of short crystals results in reduction of dechanneling losses and in increase of average number of crystal crossings by the particles. Both factors allowed an increased 70 GeV beam extraction efficiency of more than 80% which was proved experimentally and is in a good agreement with theoretical predictions. The feasibility of the crystal efficiency at injection energies (1.3 GeV) is demonstrated as well.