Resonance Control Cooling System Performance and Developments

The Spallation Neutron Source (SNS) is an accelerator-based neutron source being built at Oak Ridge National Laboratory. The warm linac portion, designed by Los Alamos, has been installed and commissioned. The warm linac is comprised of six Drift Tube Linac (DTL) tanks and four Coupled Cavity Linac (CCL) modules. For commissioning purposes the accelerating systems have been operated at less than the design 6% duty factor. During lower power operation there is less RF cavity heating. This decrease in heat load causes operational stability issues for the associated Resonance Control Cooling Systems (RCCSs) which were designed for full duty factor operation. To understand this effect operational results have been analyzed and tests have been performed. External system factors have been explored and the resulting impacts defined. Dynamic modeling of the systems has been done via a collaboration with the Institute for Nuclear Research (INR), Moscow, Russia. New RCCS operation code has been implemented. Increases in system performance achieved and solutions employed will be presented.