Light response of YAP:Ce and LaBr3:Ce scintillators to 4-30 MeV protons for applications to Telescope Proton Recoil neutron spectrometers

The light response of two thin inorganic scintillators based on YAP:Ce and LaBr3:Ce crystals has been measured with protons in the 4–8 MeV energy range at the Uppsala tandem accelerator and in the 8–26 MeV energy range at the Legnaro tandem accelerator. The crystals have been calibrated in situ with 137Cs and 60Co γ-ray sources. The relative light yields of protons with respect to gammas have been measured and are here reported to be (96±2)% and (80±2)% for YAP:Ce and LaBr3:Ce, respectively. The results open up to the development of a Telescope Proton Recoil spectrometer based on either of the two crystals as alternative to a silicon based spectrometer for applications to high neutron fluxes.