Institute for Plasma Research (IPR) has developed an indigenous Cryo-Pumping Technology to cater to the need for achieving High to Ultra-High vacuum for medium to large scale vacuum system applications. Several liquid helium cooled cryopumps were developed and tested for their performances to provide customized solutions for cryo-pumping hydrogen and helium gases for fusion applications. Liquid Nitrogen (LN2) cooled cryopump technology has been patented (Indian Patent # 504062).

These cryopumps are modular, for the ease of assembly, integration and manufacturing suitability. In the recent years, 250mm, 400mm and 500mm opening cryopumps were developed for the application in High Heat Flux Test (HHFT) Facility, SST-1 Tokamak at IPR, Cryovac chambers for SAC, ISRO.

The need for large vacuum chamber is increasing over time as the application related to fusion technologies, space and accelerator research activities in India is progressing. Vacuum pumps with high pumping speed and a vacuum characterization test facility is an important aspect and to achieve that, a Large Cryopumping Test Facility (LCTF) is under development at IPR. This includes a performance test stand for the 1250 mm diameter sized cryopumps with a pumping speed of ~50,000 l/s for nitrogen.

The cryopump within LCTF is designed to pump the atmospheric gases including Tokamak exhaust gases such as helium and hydrogen. Pumping is achieved by using different set of cryo-panels (80 K array cryo-panels, 40 K and 10 K cryo-panels) and shields. This is a hybrid type of cryopumps that contains a closed cycle cryocooler as well as LN2 annulus bath that results in low running and maintenance cost. LCTF is conceptualized and designed by IPR. Fabrication of the Cryo-Pumping Test Chamber (CTC) is completed and successfully tested in factory. During the testing, vacuum level of 1.02E-7 mbar pressure achieved in 1 hour of LN2 filling. The above pressure was maintained for 3 hours with continuous LN2 filling and ultimate vacuum achieved was 9.3E-8 mbar.

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