Shape algorithm for a RFQ vane

The Radio Frequency Quadrupole Linear Accelerator (RFQ) proposed by Kapchinskii and Teplyakov, has become an accepted structure in the accelerator community. The first working model was developed at Los Alamos for the 440 MHz cavity, and since then 200 MHz models have appeared at BNL, CERN, LBL, and KEK. The RFQ is very useful bunching low-energy ion beams and accelerating them to sufficient energies for injection into a linear accelerator. A Fermilab model of the RFQ would be a 200 MHz structure capable of accelerating H- ions from 30 keV to 750 keV in 1.36 meters. The ion current fo 50 mA would be pulsed at 15 Hz. The RFQ vane-tip parameters, m(z) and a(z) are determined along the vanes according to an algorithm developed by K. Crandall et. al. Results of this calculation are stored on paper tape and input into numerically controlled milling for vane cutting. We have used the algorithm to calculate a vane shape for the 200 MHz RFQ and have plotted the results using the Device Independent Graphics System