Characterization and stability of accelerator parameters for industrial applications

An analysis of the performance of an accelerator in an industrial environment is presented, using the IMPELA™ (Industrial Materials Processing Electron Linear Accelerator) as an example. Typically, the IMPELA is operated at 10 MeV and 50 kW. In the design of the irradiator, one of the performance goals was to ensure that the dose delivered to the product is reproducible and constant to within ±1%. The relevant critical parameters are the electron energy, the average beam current, the charge distribution across the product, and the product speed. In this paper, the design of the measurement and control of the four parameters is reviewed, with emphasis on the steps taken to ensure reproducibility and stability over time intervals from microseconds to months. Historical operating data derived from 20,000 beam hours at our commercial installations are used to demonstrate the stability achieved in practice.