SMuK 2023 – wissenschaftliches Programm

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ST: Fachverband Strahlen- und Medizinphysik

ST 9: Radiation Therapy

ST 9.5: Vortrag

Donnerstag, 23. März 2023, 16:50–17:05, ZEU/0146

First Results for Prompt Gamma Spectra measured by PETsys Electronics with 100-162 MeV Proton Beam at OncoRay TU Dresden — •Olga Novgorodova and Arno Straessner — IKTP TU Dresden, Dresden, Germany

Prompt gammas (PG) in proton therapy are one of the developing techniques for non-invasive measurements of in-vivo proton range. For the prompt gamma timing (PGT) application both time and spectral characteristics are important. Time and coincidence time resolution (CTR) studies showed already results below 100 ns. We concentrate now on the spectral properties of the system measuring PG in the range up to 8 MeV at OncoRay TU Dresden facility with proton energies between 100 to 162 MeV. A big challenge for PGT application is the data load due to the large number of photons hitting the crystal. By decreasing the size of the crystals and increasing the number of channels in the detector matrix the load to each channel can be reduced and more PGs can be detected. We are investigating CeBr₃ crystals of 5x5x20 mm³ and 10x10x30 mm³ size coupled with Sensl SiPM of 6x6 mm² with 35 µ m microcells and Hamamatsu SiPM of 6x6 mm² with 25 and 50 µ m microcells. The size of existing SiPMs is a limiting factor. For the readout electronics we optimized the PETsys electronics towards higher PG energies. It offers high photon detection efficiency, good time resolution, low bias voltage and can operate in magnetic fields. In the presentation we present first measurements of energy spectra with two different targets performed at OncoRay TU Dresden.