Evaluation of the simple LiF lens as a monochromator for inverse photoemission spectroscopy.

A LiF lens followed by a pinhole can function as an efficient vacuum ultraviolet monochromator. The principles of such an instrument are described, and its limitaions are determined using ray-tracing calculations. A practical instrument for ultraviolet inverse photoemission with resolution 0.2-0.3 eV and tunability in the 8-11.7 eV region is proposed.