Online energy verification of linear electron accelerator: Important criteria for safety and beneficial applications

Abstract

The electron beam (EB) energy is one of the most crucial parameters of EB treatment applications. It governs the dose distribution inside the bulk of the product treated with an energetic EB. An online monitoring and robust system is proposed for EB energy monitoring for radio frequency (RF) linear accelerator (LINAC). Attenuation method using dosimeter films is applied to reproduce the range of electron beam in aluminum. In online monitoring system, two electrically isolated aluminum plates having identical shape but different thicknesses, as per full penetration thickness of electron beam, are used. The current constituted in each plate is measured by an oscilloscope with suitable resistors, by keeping the set up under the beam. The ratio of the current signal from the front plate to the sum of the signals from both plates is very sensitive to the beam energy. Here, an electron accelerator of 10 MeV is used to incorporate this device. Sensitivity and robustness are the key factors to make this device highly suitable for desirous applications of 10 MeV LINAC and also to meet the regulatory mandates related to energy limitations for industrial utilities.

Keywords

• depth dose
• dosimetry
• linear accelerator
• radiochromic films
• two-plate method