Measurement of high Rydberg states and the ionization potential ofH2

Abstract

We have measured numerous transitions from the $E$, $F$ state of ${\mathrm{H}}_2$ to the singlet $\mathrm{np}$ Rydberg states with an accuracy of 0.01 ${\mathrm{cm}}^{-1\mathrm{}}$. The data have been analyzed to obtain values for the ionization potential of ${\mathrm{H}}_2$ relative to the $v=0\mathrm{}$, $N=0\mathrm{} \mathrm{and} 1$ levels of the $E$, $F$ state. By combining these results with previous measurements of the $E$, $F$ state, a value of 124 417.524±0.015 ${\mathrm{cm}}^{-1\mathrm{}}$ is obtained for the ionization potential of ${\mathrm{H}}_2$. This result is in good agreement with previous work but nearly an order of magnitude more accurate, and is very close to the best theoretical value.