FY24 SBIR PHASE II TOPIC NO. 434 PROJECT TITLE: 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 FLASH irradiation beam parameters such as dose, dose per pulse, pulse repetition frequencies, and time structure with the available conventional radiation detectors, electrometers, and dosimetry protocols. In Phase I, we designed and constructed a novel NIST-traceable ionization chamber prototype for FLASH dosimetry. We also developed a prototype electrometer that can provide time-resolved data. For Phase II, we will finalize construction methods and materials of the ionization chamber, and we will further enhance the electrometer to achieve higher frequency monitoring of the measured signal, improve impulse response of the electrometer, and prepare for commercialization. In addition, we will fully characterize the final dosimetry system in FLASH beamlines to prepare for commercial release. Although we plan to verify performance in both proton and electron FLASH beams, the ultimate test of an ion chamber and electrometer 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. This dosimetry system is urgently needed to bring FLASH RT dosimetry up to the standard required for clinical RT.