Using a pre-kicker to ensure safe extractions from the HEPS storage ring

Zhe Duan,Yu-Wen Wu,Hua Shi,Guang-Yi Tang,Jin-Hui Chen,Lei Wang

doi:10.1007/s41365-021-00974-z

Abstract

The High Energy Photon Source (HEPS) is a 6 GeV diffraction-limited storage ring light source under construction. The swap-out injection is adopted with the depleted bunch recycled via high-energy accumulation in the booster. The extremely high beam energy density of the bunches with an ultra-low emittance (about 30 pm horizontally and 3 pm vertically) and high bunch charges (from 1.33 to 14.4 nC) extracted from the storage ring could cause hazardous damage to the extraction Lambertson magnet in case of extraction kicker failure. To this end, we proposed the use of a pre-kicker to spoil the bunches prior to extraction, significantly reducing the maximum beam energy density down to within a safe region while still maintaining highly efficient extractions. The main parameters of the pre-kicker are simulated and discussed.

Highlights

The High Energy Photon Source (HEPS) [1] is a 6 GeV diffraction-limited storage ring (DLSR) light source under construction in Huairou Science City, Beijing, China
We proposed the use of a pre-kicker to spoil the bunches prior to extraction, significantly reducing the maximum beam energy density down to within a safe region while still maintaining highly efficient extractions
To satisfy versatile user experiments, two filling patterns are considered for HEPS: the high-brightness mode employs 680 bunches with a single bunch charge of 1.33 nC and provides hard X-ray synchrotron radiations at a brightness of 5 Â 1022 photons sÀ1 mmÀ2 mradÀ2ð0:1% bandwidthÞÀ1 while the high-bunch-charge mode employs 63 uniformly distributed bunches with a single bunch charge of 14.4 nC to meet the needs of timing experiment users for high flux radiations with a specified time structure

Summary

Introduction

The High Energy Photon Source (HEPS) [1] is a 6 GeV diffraction-limited storage ring (DLSR) light source under construction in Huairou Science City, Beijing, China. For a highly dense beam comparable to the high-bunch-charge mode, the estimated maximum radiation dose was larger than the result of the FLUKA simulation.

Results

Conclusion