Dry Pumps in Accelerator—Usage at the Japan Proton Accelerator Research Complex (J-PARC)—

This report describes the usage, specification, troubles and the countermeasures of dry pumps in Japan Proton Accelerator Research Complex (J-PARC). In J-PARC, while dry scroll pumps (DSP) are widely used, many of them are being replaced with roots pumps due to frequent maintenance and troubles of DSP. Some of the facilities use roots pumps with special specifications, such as radiation resistant specifications, separate power supply, and with diaphragm type, etc. Although some problems have occurred with both DSPs and roots pumps, they have been addressed by revising maintenance methods and improving parts, contributing to stable operation for users.