Fabrication and testing of 2K cryostat for vertical test facility at RRCAT

Raja Ramanna Centre for Advanced Technology (RRCAT) has developed a 2K Cryostat for characterization of Superconducting RF (SRF) cavities, under Indian Institution Fermilab Collaboration (IIFC). A vertical Test Stand (VTS) is a facility for qualifying bare SRF cavities for their required performance by measuring quality factor and cavity accelerating gradient at a cryogenic temperature of 2K. The VTS cryostat has been designed for a large testing aperture for testing variety of SRF cavities including 325 MHz Spoke resonators, 650 MHz and 1.3 GHz multi-cell SRF cavities. The engineering design and analysis of VTS cryostat has been carried out using ASME B&PV Code and Finite Element Analysis. Fabrication of Cryostat was carried out in strict accordance with ASME B&PV code under joint supervision of engineers from RRCAT and Fermilab. The paper describes the fabrication & acceptance testing aspects of the VTS cryostat at the vendor location and at RRCAT.