Performance Study of Liquid Nitrogen Thermo-Siphon Cooling Loop

Abstract

A RF-superconducting linear accelerator (LINAC) booster for the existing 15UD Pelletron accelerator is presently under construction at Inter-University Accelerator Centre in New Delhi, India. The LINAC will make use of superconducting niobium quarter-wave resonators (QWR) as the accelerating element, and will consist of three accelerating cryomodules. A gravity-assisted (thermo-siphon) flow scheme with liquid nitrogen has been proposed to cool the thermal radiation shields of the LINAC cryomodules. A small test rig of the thermo-siphon loop has been developed to simulate and investigate the chosen aspects of the proposed configuration. The experimental work has been focused on the thermal performances of the specially designed copper clamps and optimization of the system engineering parameters. The paper presents the results of the thermo-siphon measurements and the qualitative description of the investigated phenomena.