Reconfiguring a Plane-Parallel Transmission Ionization Chamber to Extend the Operating Range into the Ultra-High Dose-per-pulse Regime.

This study aims to investigate the feasibility of enhancing the charge collection efficiency (CCE) of a transmission chamber by reconfiguring its design and operation. The goal was to extend the range of dose-per-pulse (DPP) values with no or minimal recombination effects up to the ultra-high dose rate (UHDR) regime. The response of two transmission chambers, with electrode distance of 1 mm and 0.

Beam control system and output fine-tuning for safe and precise delivery of FLASH radiotherapy at a clinical linear accelerator.

Introduction: We have previously adapted a clinical linear accelerator (Elekta Precise, Elekta AB) for ultra-high dose rate (UHDR) electron delivery. To enhance reliability in future clinical FLASH radiotherapy trials, the aim of this study was to introduce and evaluate an upgraded beam control system and beam tuning process for safe and precise UHDR delivery.

Materials And Methods: The beam control system is designed to interrupt the beam based on 1) a preset number of monitor units (MUs) measured by a monitor detector, 2) a preset number of pulses measured by a pulse-counting diode, or 3) a preset delivery time.