OPERATION OF THE SUPERCONDUCTING LINAC AT THE SPALLATION NEUTRON SOURCE

At the Spallation Neutron Source, the first fully operational pulsed superconducting linac has been active for about two years. During this period, stable beam operation at 4.4 K has been achieved with beam for repetition rates up to 15 Hz and 30 Hz at 2.1 K. At the lower temperature 60 Hz RF pulses have been also used. Full beam energy has been achieved at 15 Hz and short beam pulses. Most of the time the superconducting cavities are operated at somewhat lower gradients to improve reliability. A large amount of data has been collected on the pulsed behavior of cavities and SRF modules at various repetition rates and at various temperatures. This experience will be of great value in determining future optimizations of SNS as well in guiding in the design and operation of future pulsed superconducting linacs. This paper describes the details of the cryogenic system and RF properties of the SNS superconducting linac.