Spallation Neutron Source Drift Tube Linac Resonance Control Cooling System Modeling

The Resonance Control Cooling System (RCCS) was designed by Los Alamos National Laboratory for the warm linac of the Spallation Neutron Source. The primary design focus was directed on water-cooling of individual component contributions. The sizing of the RCCS water skid was accomplished by means of a specially created SINDA/FLUINT model tailored to these system requirements. A new model was developed in Matlab Simulink and incorporates actual operational values and control valve interactions. The model took into consideration the dependence of RF input power on cavity detuning values during transients, time delays that resulted from water flows through the heat exchanger, the dynamic process of water warm-up in the cooling system due to dissipated RF power on the cavity surface, differing contributions on the cavity detuning due to drift tube and wall heating, and a dynamic model of the heat exchanger with characteristics, which were in close agreement to the real unit. Because of the Matlab Simulink model, investigation of a wide range of operating issues during both transient and steady state operation is now possible. Some results of the DTL RCCS modeling are presented.