Design and commissioning of Fermilab's vertical test stand for ILC SRF cavities

As part of its ILC program, Fermilab is developing a facility for vertical testing of SRF cavities. It operates at a nominal temperature of 2 K, using a cryoplant that can supply LHe in excess of 20 g/sec and provide bath pumping capacity of 125 W at 2 K. The below-grade cryostat consists of a vacuum vessel and LHe vessel, equipped with magnetic shielding to reduce the ambient magnetic field to ≪10mG. Internal fixed and external movable radiation shielding ensures that exposure to personnel is minimzed. The facility features an integrated personnel safety system consisting of RF switches, interlocks, and area radiation monitors.