The vacuum ultraviolet light source (VUV) produces photons in the 8.4 - 48.4 eV energy region by exciting different noblegas atoms with the help of ECR plasma.

The vacuum ultraviolet light source (VUV) produces photons in the 8.4 - 48.4 eV energy region by exciting different noblegas atoms with the help of ECR plasma. The narrow band of wavelengths of light is created by monochromators. Furthermore a polarizator was also installed in the system.  The VUV source is installed at the entrance of the ESA-22 electronspectrometer in order to measure the angular distribution of photoelectrons originated from different target gases.