Computer simulation of multitum beam extraction from accelerators by bent crystals

Abstract Multiturn extraction of 70 GeV protons from the IHEP accelerator by a silicon crystal bent along (110) planes has been studied by a computer simulation. It is shown that the extraction efficiency increases due to multiple passages of particles through the crystal deflector, when its length and, accordingly, the beam disturbance are small. Moreover, cooling of the accelerator beam fraction by the bent crystal owing to the volume reflection of particles by the field of bent atomic planes was discovered.