A Wide Dynamic Range 10 MeV High Current Electron Linear Accelerator

The salient features of a new high power linear accelerator system are described. This machine combines a 300 kV dc accelerator, constructed for operation with pulsed currents in excess of 2A, with a single section 10 MeV accelerator waveguide so that given levels of high peak current may be maintained over a wide range of beam energies. (Previous technology required RF phase and/or power adjustment to a second accelerator section.) The accelerator waveguide incorporates a suppressed phase oscillation buncher designed so that a loss of terminal electric field strength, caused by a large reduction of input RF power to reduce beam energy, may be accurately compensated by an increase in potential of the dc accelerator, thus maintaining the capture efficiency of the waveguide. Reduction of space charge forces due to HV injection, and avoidance of dual section operation, prove to be major operational advantages. The 20 MW RF transmitter and the overall beam centerline are described; and operating performance and equipment photographs are presented.