PROGRESS IN LOW-BETA, LOW Q A RFQS AT INS

Two split coaxial RFQ's (SCRFQ's) are presented. Both operate at 25.5 MHz and accelerate ions with a charge-to-mass ratio q/A greater than 1 /30. One SCRFQ is a prototype (0.9 m diameter, 2.1 m length, 45 keV/u output energy), and the other is its extended version (0.9 m, 8.6 m, 1 72 keV/u). The prototype was constructed in 1989 and underwent rf and acceleration tests for two years. Through experience obtained with the prototype SCRFQ, we are now constructing the longer machine. The cavi ty construction is to be finished in the spring of 1994. The new SCRFQ will be used as the front-end linac in the E-Arena Test Facility, now under construction in INS. In the facility radioactive nuclei will be accelerated by the SCRFQ and an interdigital-H linac (the output ener gy is variable in a range of 172 through 1046 keV/u) and delivered to nuclear physics experiments.