CONVERSION OF THE 2.5MV SUPER HILAC INJECTOR POWER SUPPLY FROM 5mA TO 50mA FOR BORON NEUTRON CAPTURE THERAPY* 1

Renewed interest by several major university medical centers (UCSF-Standford, UC-Davis) in conducting Boron Neutron Capture Therapy (BNCT) led to the investigation of converting the decommissioned 5mA, 2.5MV Super HILAC injector to a 50mA, 2.5MV proton accelerator for the gener ation of neutrons. The original high impedance shunt-fed multiplier has been converted to a 55 stage air-coupled transformer with much lower impedance driven by a 200kW, 50kHz oscillator. The proton beam will be transported by electrostatic quadrupoles (ESQ) acceleration column housed axially within the power supply stages and biased by connecting sequentially to the desired voltage. The pressure vessel which houses the 2.5MV power supply and ESQ acceleration column has been moved near the patient treatment rooms in the Bevatron complex. As funds become available, we will finalize the design and assembly of all components required for the generation, transport and conversion of the proton beam to neutrons for patient treatment. Preliminary tests of the power supply and design of the ESQ column will be presented.