FY22 SBIR TOPIC 434 PHASE I - NOVEL NIST TRACEABLE IONIZATION CHAMBER FOR FLASH DOSIMETRY.

限制FLASH RT临床前和临床使用的主要因素之一是难以使用现有的常规辐射探测器、静电计和剂量测定方案测量FLASH辐照参数，例如剂量、每脉冲剂量、脉冲重复频率和时间结构。本计画的目标是设计并建构一个新颖的NIST追踪式电离室，以进行FLASH剂量测量。我们还将开发一种标准级静电计，以实现对测量信号的高频监测，提供整个辐照的综合剂量测量和有关FLASH辐照期间提供的单个脉冲的时间分辨信息。这两种仪器都将具有NIST可追溯性。为了实现这一目标，我们的目标是确定最佳的电离室设计的FLASH RT，使用我们现有的静电计作为跳板，创造一个新的静电计，快速响应FLASH照射，并充分表征工作的原型系统在FLASH光束线。虽然我们计划验证质子和电子闪光束的性能，但为闪光束绝对剂量测定而开发的离子室的最终测试将在电子闪光束线中进行，因为这些束线具有最高的瞬时剂量率和可用模式的每脉冲剂量。

One of the major factors limiting pre-clinical and clinical use of FLASH RT is the difficulty in measuring the FLASH irradiation parameters such as dose, dose per pulse, pulse repetition frequencies, and time structure with the available conventional radiation detectors, electrometers, and dosimetry protocols. The goal of this project is to design and construct a novel NIST-traceable ionization chamber for FLASH dosimetry. We will also develop a standards-level electrometer to achieve high frequency monitoring of the measured signal, providing both integrated dose measurements for the entire irradiation and time-resolved information about individual pulses delivered during FLASH irradiations. Both instruments will be NIST traceable. To reach this goal, we aim to determine the optimal ionization chamber design for FLASH RT, to use one of our existing electrometers as a springboard for creating a new electrometer that responds rapidly to FLASH irradiation, and to fully characterize a working prototype system in FLASH beamlines. Although we plan to verify performance in both proton and electron FLASH beams, the ultimate test of an ion chamber developed for absolute dosimetry in FLASH beams will be in electron FLASH beamlines because these have the highest instantaneous dose rates and dose per pulse of the available modalities.