Low Gain Avalanche Detectors for Proton-Ct

Abstract

With increasing number of hadron therapy centres the need for proton-CT as a powerful imaging technique is growing. Although a number of experimental p-CT has been developed there is no clinical p-CT yet. The imaging technique is based on measuring entry and exit point of the proton from the tissue as well as the residual energy of the proton. The latter is very demanding in terms of high particle rates and required resolution. The p-CT concept using novel Low Gain Avalanche Detectors (LGADs) will be described where three layers of LGAD timing detectors are used to measure the proton track and its energy. The measurement of proton energy which is vital for image reconstruction (density of electrons) is obtained from time-of-flight measurements rather than conventional scintillator-based calorimeter. The first-time resolution measurements with very thin (35 µm) LGADs and GEANT4 simulations of the p-CT performance are presented.