ELECTRON ACCELERATOR CONTROL SYSTEM BASED ON RADIATION-ACOUSTIC EFFECTS

G.F.Popov, V.A.Deryuga, A.I.Kalinichenko,
Yu.A.Kresnin and N.G.Stervoedov

Kharkiv State University, Kharkiv, Ukraine



The system was designed to control a traveling-wave linear accelerator with the use of ultrasonic signals which are generated by the electron beam and by a high-frequency electromagnetic field on their interactions with the accelerator construction elements and with a target. It incorporates a set of broadband acoustic sensors, two CAMAC crates and an IBM PC-compatible computer with corresponding software. The crate A fulfils the h.f. field phase-locking in the accelerating cavity and controls transmitting the beam through the transfer line. The phase-locking is executed based on twin signals from an acoustic sensor placed on an absorbing load of the accelerating waveguide. The system operates to make the amplitudes of the twin equal; that corresponds to the maximum of h.f. energy transfer. The control of beam transmitting is executed based on signals from acoustic sensors placed on a diaphragm in an electron transfer line. The determination of the beam position is executed on the base of delays of the acoustic pulses against the sync pulse of the accelerator. The crate B fulfils focusing the beam to the target and measuring duration, energy, and current of the beam on the base of signals from sensors placed on the target. There is a supervision program which keeps minutes of experiment, displays current information, allows the system to be tested, the beam parameters to be changed, the dose profile in the target to be calculated. The system can be useful for the control of multiple cavity accelerators and for protection of high-current accelerators against damages caused by their own beams.