The SNS RFQ prototype module

The RFQ included in the Front End injector for the Spallation Neutron Source (SNS) operates at 402.5 MHz, with a maximum H^- input current of 70 mA at a 6% duty factor. It is 3.72 m long and consists of four equally long modules. A brazed copper structure has been chosen due to the high power, high duty factor operation. The 1 MW peak r.f. power is coupled into the structure via eight ports, two per module. Quadrupole mode stabilization is obtained with a set of π-mode stabilizing loops. The conceptual design has been completed, and a single, full size prototype RFQ module has been designed and is under construction to test the fabrication processes and r.f. performance. It will be operated at full r.f. power in order to test its cooling scheme, dual temperature water tuning, mode stabilization and beam acceptance. The detailed design, assembly processes, thermal analyses and a status report for the prototype module are presented