Design of dynamic collimator for J-PARC main ring

Abstract

The J-PARC main ring has a beam collimator section downstream of the injection area. The allowed beam loss is about 450 W. The beam halo generated before acceleration can be scraped by a standard collimator scheme. However the beam halo can grow during the acceleration. Such a halo may cause a serious beam loss at the extracion. A collimation during acceleration (dynamic collimator) is useful to reduce the beam loss at the extraction. We propose the dynamic collimator scheme and show the performance expected from the simulations.

Accelerator Engineering and Technology: Accelerator Technology

“…The first two-stage collimation systems were constructed for HERA [219], Tevatron [220,221] and RHIC [222]. The 2000's took modern collimator technology to linac-based, GeV range energy, high power facilities [223][224][225][226][227][228][229][230][231], where multi-stage collimation is required for ensuring handson maintenance and reducing environmental impact of high power accelerators. At the same time collimator technology was developed for linear collider concepts [232].…”

Geometric efficiency of a two-stage fully absorbing collimation system in single-pass linacs

“…Collimation systems are used both on linear [2][3][4][5][6][7] and on circular accelerators [8][9][10] to minimize background in physics detectors, to avoid quench magnets in superconducting machines, and to limit the irradiation of equipment, possibly leading to demagnetization of undulator permanent magnets. The need of high luminosities in colliders and in linac-based free electron lasers (FELs) obtained with high beam intensities makes these problems even more serious.…”