Compact Embedded Detection Electronics for Accurate Dose Measurements of MV Pulsed X-rays and Electrons

Abstract

Modern radiation therapies in which ultra-narrow, collimated radiation beams are used to treat even irregular tumor geometries are leading to new challenges in dosimetry. In this context, FLASH technique, involving the use of high dose-rates as well as ultra-high dose-per-pulse beams, is receiving more and more attention. On this basis, the development of detection systems capable of meeting the stringent requirements of dose-per-pulse monitoring, such as real-time acquisition and processing of dosimeter signals, is becoming crucial. In this work, the main features of a synthetic single-crystal diamond dosimeter coupled to a specifically designed compact and versatile front-end electronics are illustrated. Proposed system is able to monitor the generated charge by the detector at every pulse on the impinging beam. Tests were performed for synchronous measurements under either X-ray photons or electrons generated by a medical linear accelerator, with an accelerating voltage of 6 MV. Experimental results highlight that diamond dosimeter displays a response only dependent on the impinging dose regardless of the beam nature (X-rays or electrons), therefore confirming that diamond is the elective material for accurate dosimetry in radiotherapy. The system acquires, processes and transfers the data within 0.5 ms, thus allowing for a real time monitoring for pulse repetition rates up to more than 2 kHz. Exploiting the high quality of the implemented components, the proposed front-end and read-out electronics represents an effective solution for accurate dose-per-pulse measurements in modern radiotherapy techniques.