Conceptual Design of the SNS RFQ

Abstract

The conceptual design of the RFQ included in the front end injector of the Spallation Neutron Source is described. The RFQ operates at 402.5 MHz, with a maximum H-input current of 70 mA and 6 % duty factor. It is 3.72 m long and made out of four equally long modules. A brazed copper structure has been chosen due to the high power, high duty factor operation. The 800 kW peak r.f. power is coupled into the structure via eight ports, two per section. A set of tuners is provided for final frequency adjustment and local field perturbation correction. Quadrupole mode stabilization is obtained with a set of pi-mode stabilizing loops. The conceptual design, assembly processes and status report are presented. This paper reports and updates the status of the design since it was last described [1].