Dead layer measurements for KATRIN prototype PIN diode array

Dead layer measurements for a prototype PIN diode array for the KATRIN (KArlsruhe TRItium Neutrino) experiment are presented. KATRIN is a direct neutrino mass measurement of tritium beta decay near the electron endpoint energy of 18.6 keV. A neutrino mass sensitivity goal for KATRIN is m(v_e) < 0.2 eV. The methods used to determine the dead layer include the standard angle method, commonly found in texts, and the newly developed energy method. An average dead layer across the entire array of 119 plusmn 3 nm and 109 plusmn 3 nm, was found respectively for the two methods.