Year : 2013, Volume : 38, Issue : 1to4
First page : ( 173) Last page : ( 177)
Print ISSN : 0379-0479. Online ISSN : 2349-2120. Published online : 2013  3.

Performance of helium recondenser for quadrapole magnet cryostat

Choudhury Anup¹, Datta T S¹

¹Inter University Accelerator Centre (IUAC), Aruna Asaf Ali Road, PO Box- 10502, New Delhi, 110067

Abstract

A superterric superconducting quadrupoie doublet magnet cryostat is currently under fabrication at our institute. This cryostat will be located far off from the existing cryogenic distribution facility and hence the cryostat design is done based on the cooling capacities provided by a two stage GM cryocooler. Cryocooier 1^st stage cooling power will be used to coot the copper shield to 60 K and HTS leads and the second stage cooling power will be used to recycle the cold helium gas through a liquid helium recondenser hoat exchanger apart from the radiation load from 60K shield and instrumentation wiring. A helium recondenser with a surface area of 0.15 m² in a compact volume has been designed, fabricated and tested. To have maximum enhanced area per unit volume fin like straight grooves were cut into an OFHC copper block deep down. A detailed thermal analysis of the recondenser has been carried out both theoretically and experimentally. LHe production rate achieved was 0.88 liter per day (Ipd) and the measured refrigeration capacity in the setup was maximum 2.26 watt at an equilibrium pressure of ∼56537 Pa inside the refrigeration chamber. Also study was conducted to measure the recondensation capacity at various input power in liquid helium against the stabilized chamber pressure and at the same time temperature at various points was measured. This paper will discuss the design aspect of the heat exchanger, and the performance w.r.t. refrigeration capacity at various pressure and temperature.

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Keywords

Recondenser, Cryocooier, Superconductor magnet, Cryostat, UHV Vacuum vessel.

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