A Large 1.8 K Facility for Magnet Tests

A large test facility for 1.8 K operation of superconducting magnet models has been built at CEN/Saclay. This facility is intended for testing accelerator magnets developed at CERN for the LHC program. It is designed in such a way that magnet models can be operated either in an existing thermally-insulated vacuum tank or directly in their own cryostat, which enables magnets of any length or strings of magnets to be tested. This facility consists of a 4.4 K, 200 W refrigerator (to be replaced shortly by a 450 W unit) and a satellite module including the 1.8 K, 30 W refrigerator stage and two 20 kA current leads interfaced with the magnet cryostat. Peripheral equipment includes a 20 kA power supply, dump resistors and circuit breakers for magnet protection, magnetic field mapping and harmonic analysis system, fully automated control system and computerized slow and fast data acquisition. A first short length dipole has been tested in January 1989 reaching a field of 9.3 T.