Performance of CVD diamond detectors for single ion beam-tagging applications in hadrontherapy monitoring

Sébastien Curtoni (1) , Marie-Laure Gallin-Martel (1) , Latifa Abbassi (2) , Alexandre Bes (1) , Germain Bosson (1) , Johann Collot (1) , Thierry Crozes (2) , Denis Dauvergne (1) , Wout de Nolf (3) , Pierre Everaere (1) , Laurent Gallin-Martel (1) , Abderrahmane Ghimouz (1) , Ferid Haddad (4, 5) , Christophe Hoarau (1) , Jean-Yves Hostachy (1) , Charbel Koumeir (4, 5) , Ana Lacoste (1) , Sara Marcatili (1) , Vincent Métivier (4) , John Morse (3) , Jean-François Motte (2) , Jean-François Muraz (1) , Freddy Poirier (4, 5) , Fatah Ellah Rarbi (1) , Olivier Rossetto (1) , Muriel Salomé (3) , Noël Servagent (4) , Étienne Testa (6) , Mahfoud Yamouni (1)

1 LPSC - Laboratoire de Physique Subatomique et de Cosmologie
2 NEEL - Nanofab - Nanofabrication
3 ESRF - European Synchrotron Radiation Facility [Grenoble]
4 SUBATECH - Laboratoire de physique subatomique et des technologies associées
5 GIP ARRONAX [Nantes]
6 IP2I Lyon - Institut de Physique des 2 Infinis de Lyon

In the context of online ion range verification in particle therapy, the CLaRyS collaboration is developing Prompt-Gamma (PG) detection systems. The originality in the CLaRyS approach is to use a beam-tagging hodoscope in coincidence with the gamma detectors to provide both temporal and spatial information of the incoming ions. The ion range sensitivity of such PG detection systems could be improved by detecting single ions with a 100 ps (sigma) time resolution, through a quality assurance procedure at low beam intensity at the beginning of the treatment session. This work presents the investigations led to assess the performance of Chemical Vapor Deposition (CVD) diamond detectors to fulfill these requirements. A 90Sr beta source, 68 MeV protons, 95 MeV/u carbon ions and a synchrotron X-ray pulsed beam were used to measure the time resolution, single ion detection efficiency and proton counting capability of various CVD diamond samples. An offline technique, based on double-sided readout with fast current preamplifiers and used to improve the signal-to-noise ratio, is also presented. The different tests highlighted Time-Of-Flight resolutions ranging from 13 ps (Sigma) to 250 ps (Sigma), depending on the experimental conditions. The single 68 MeV proton detection efficiency of various large area polycrystalline (pCVD) samples was measured to be >96% using coincidence measurements with a single-crystal reference detector. Single-crystal CVD (sCVD) diamond proved to be able to count a discrete number of simultaneous protons while it was not achievable with a polycrystalline sample. Considering the results of the present study, two diamond hodoscope demonstrators are under development: one based on sCVD, and one of larger size based on pCVD. They will be used for the purpose of single ion as well as ion bunches detection, either at reduced or clinical beam intensities.

Mots clés: CVD diamond; hadrontherapy; ion range verification; time resolution; detection efficiency; particle counting; beam monitoring

Domaines: Instrumentations et Détecteurs [physics.ins-det]; Physique Médicale [physics.med-ph]

Sébastien Curtoni, Marie-Laure Gallin-Martel, Latifa Abbassi, Alexandre Bes, Germain Bosson, et al.. Performance of CVD diamond detectors for single ion beam-tagging applications in hadrontherapy monitoring. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2021, 1015, pp.165757. ⟨10.1016/j.nima.2021.165757⟩. ⟨hal-03227464⟩