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

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.