Under DAE-CERN collaboration, CAT was entrusted with the development, fabrication, cryogenic testing at 4.2 K, and room temperature magnetic field measurement of a large number of sextupole and decapole corrector magnets. As the number of magnets being very large, it was decided to augment the exiting small test set up by developing a large diameter LHe cryostat which can hold six numbers of corrector magnets at a time for testing at single filling of liquid helium. A straight bore pool type cryostat is developed in which a magnet insert can be mounted and removed easily. A 350 mm dia 1700 mm deep He capacity was chosen allowing two sextupole corrector magnets in each three layers on the insert. About 70 lit of helium submerges all six magnets up to 700 mm, leaving a neck of about 1000 mm for a sufficient thermal gradient to room temperature. The figure below shows the cryostat being assembled.