Photopeak shift effects due to the drift electric field in high pressure xenon detectors

The photopeak shift in High Pressure Xe (HPXe) gamma ray detectors due to the energy acquired/lost by the photoelectric and Compton electrons, from the electric field applied in the drift region, is calculated using the PENELOPE code for gamma rays from several radioactive sources. The implications of this effect in HPXe detectors are discussed, namely for TPCs for double beta decay of ¹³⁶Xe studies.