Proton irradiation of CVD diamond detectors for high-luminosity experiments at the LHC

CVD diamond shows promising properties for use as a position-sensitive dete ctor for experiments in the highest radiation areas at the Large Hadron Col lider. In order to study the radiation hardness of diamond we exposed CVD d iamond detector samples to 24 Gev/c and 500 Mev protons up to a fluence of 5 x 10(15) p/cm(2). We measured the charge collection distance, the average distance electron-hole pairs move apart in an external electric field, and leakage currents before, during, and after irradiation. The charge collect ion distance remains unchanged up to 1 x 10(15) p/cm(2) and decreases by ap proximate to 40% at 5 x 10(15) p/cm(2) Leakage currents of diamond samples were below 1 pA before and after irradiation. The particle-induced currents during irradiation correlate well with the proton flux. In contrast to dia mond, a silicon diode, which was irradiated for comparison, shows the known large increase in leakage current. We conclude that CVD diamond detectors are radiation hard to 24 GeV/c and 500 MeV protons up to at least 1 x 10(15 ) p/cm(2) without signal loss. (C) 1999 Elsevier Science B.V. All rights re served.