DETERMINING PHASE-SPACE PROPERTIES OF THE LEDA RFQ OUTPUT BEAM
Quadruple scans were used to characterize the LEDA RFQ beam. Experimental data were fit to computer simulation models for the rms beam size. The codes were found to be inadequate in accurately reproducing details of the wire scanner data. When this discrepancy is resolved, we plan to fit using all the data in wire scanner profiles, not just the rms value.
Operations of the LEDA resonantly coupled RFQ
The LEDA RFQ is a 350-MHz continuous-wave (CW) radio-frequency quadrupole linac. LEDA is the low energy demonstration accelerator, a full power front-end prototype for the accelerator production of tritium (APT) linac. This machine has accelerated a 100-mA CW proton beam from 75 keV to 6.7 MeV. The 8-m-long RFQ accepts a dc, 75-keV, /spl sim/110-mA H/sup +/ beam from the LEDA injector, bunches the beam, and accelerates it to full energy with /spl sim/94% transmission. The output beam power is 670 kW. This RFQ consists of four 2-meter-long RFQs joined with resonant coupling to form an 8-meter-long RFQ. The resonant coupling improves the stability of both the longitudinal and transverse RF-field distribution in this long RFQ.
APT/LEDA RFQ vacuum pumping system
This paper describes the design and fabrication of a vacuum pumping system for the APT/LEDA (Low Energy Demonstration Accelerator) RFQ (Radio Frequency Quadrupole) linac. Resulted from the lost proton beam, gas streaming from the LEBT (Low Energy Beam Transport) and out-gassing from the surfaces of the RFQ cavity and vacuum plumbing, the total gas load will be on the order of 7.2/spl times/10/sup -4/ Torr-liters/sec, consisting mainly of hydrogen. The system is designed to pump on a continual basis with redundancy to ensure that the minimal "operating vacuum level" of 1/spl times/10/sup -6/ Torr is maintained even under abnormal conditions. Details of the design, performance analysis and the preliminary test results of the cryogenic pumps are presented.