In this paper we report the experimental study of high-pressure xenon used as a scintillator, in the context of developing a gamma ray detector. We measure a light yield near 2 photoelectrons per keV for xenon at 40 bar. Together with the light yield
, we also measured an energy resolution of ~9% (FWHM) at 662 keV, dominated by the statistical fluctuations in the number of photoelectrons.
