Fine structure measurements of high-L Rydberg states of H$_{2}$.

Measurement of the fine structure pattern of high-angular momentum Rydberg states provides information about the basic properties of the ion core, such as the polarizability. Recently a \underline {r}esonant \underline {e}xcitation \underline {S}tark \underline {i}onization \underline {s}pectroscopy (RESIS) apparatus has been constructed at the SUNY Fredonia campus. A Doppler-tuned CO$_{2}$ laser resonantly excites transitions in a fast molecular beam, which are detected by Stark ionization. We report here our experimental progress in the fine structure measurements of high-L Rydberg states of the ground vibrational state of molecular hydrogen.