In this publication, the detailed spectral characterization of the concentrated radiation of PSI’s 50 kW xenon arc lamp based solar simulator (HFSS) is reported. Spectra are presented for the range of 350–1600 nm recorded at different radial distances from the position of maximum concentration, i.e., from the center of the spot. The analysis shows that the relative intensity of the short wavelength region decreases with increasing radial distance from the center of the spot. At the same time, the relative contribution of the xenon emission lines increases. All spectra can be decomposed into a broad background described by a blackbody spectrum with a temperature of T = 6000 ± 200 K and the characteristic line spectrum of xenon.