Modification of a medical linac to a polymer irradiation facility

A linear accelerator for X-ray therapy has been modified to generate a 5 MeV pulsed electron beam. The main objective is to irradiate polymeric materials in open air in order to alter their chemical and mechanical properties. To meet the radiation protection standards a shielding has been built round the target. Safety is guaranteed by a fail-safe secured programmable logic controller (PLC) monitored by a personal computer. The accelerator can be monitored and controlled by a graphics oriented and menu driven program running on the personal computer. In addition, a control panel has been designed and built to show warning signals and to set various linac parameters. A description of the accelerator modification and of the new control system is presented. (orig.)