CRYOSTAT DESIGN AND ANALYSIS OF THE SUPERCONDUCTING MAGNETS FOR JEFFERSON LAB’S 11 GEV/C SUPER HIGH MOMENTUM SPECTROMETER

This paper describes the mechanical design and analysis of the cryostats for the two cos(2 theta) quadrupoles and the cos(theta) dipole. All the magnets are currently being bid for commercial fabrication. The results of finite element analysis for the magnet cryostat helium vessels and outer vacuum chambers which investigate the mechanical integrity under maximum allowable internal working pressure, maximum allowable external working pressure, and cryogenic temperature are discussed. The allowable stress criterion is determined based on the allowable stress philosophy of the ASME codes. The computed cryogenic heat load of the magnets is compared with the allowable cryogenic consumption budget. The presented cool-down time of the magnets was studied under the conditions of a limited supply rate and a controlled temperature differential of 50 K in the magnets.