A readout system for highly sensitive diamond detectors for FLASH dosimetry

S. Pettinato^1,2; G. Felici³; L. Galluzzo³; M. Girolami²; M.C. Rossi⁴ and S. Salvatori^1,2

1. Department of Engineering, University “Niccolò Cusano”, 00166 Rome, Italy
2. Istituto di Struttura della Materia, Consiglio Nazionale delle Ricerche (ISM-CNR), 00016 Rome, Italy
3. SIT, Sordina IORT Technologies S.p.A., Aprilia, Latina, Italy
4. Department of Industrial, Electronic, and Mechanical Engineering, Roma Tre University, 00146 Rome, Italy

Accurate dosimetry of ultra-high-dose-rate beams using diamond detectors remains challenging, primarily due to high photocurrent peaks that exceed the input dynamics of precision electrometers. This work aimed to demonstrate the effectiveness of compact gated integration electronics in conditioning current peaks (>20 mA) generated by a custom-designed, highly sensitive diamond photoconductor (S ≃ 26 nC/Gy) under electron flash irradiation, as well as in real-time monitoring of beam dose and dose rate. This research marks the first implementation of the gated integration technique for real-time monitoring of high current peaks generated by a diamond detector subjected to intense electron beams. Measurement of the collected charge, limited to the time period around the incident pulse, ensures an optimal signal-to-noise ratio. Surprisingly, the versatility of the proposed instrument paves the way for the use of commercial diamond dosimeters already proven in conventional radiotherapy, even in the context of flash dosimetry.
For the emerging FLASH technology, this study offered a new perspective on the use of commercially available high-sensitivity diamond dosimeters, currently used in conventional radiotherapy.