VUV reflection spectra of PbWO4 single crystals

The reflection (R) spectra of PbWO4 monocrystals in the vacuum ultraviolet region of 2 to 41 eV have been determined using the Storage Ring of the Synchrotron Center of Novosibirsk as radiation source. The reflection spectra were employed to calculate the spectral dependences of the dielectric constants, refractive index, absorption index, characteristic loss function, joint density of states, and the effective number of valence electrons in the unit cell. The analysis of the R spectra allowed to confirm that the triplet at 21.5, 22.9, and 23.8 eV is attributed to the intracentre transitions in the Pb2+ ion, whereas the peaks at 35.5 and 37.6 eV may be attributed to O2s → Pb6p transitions