High-Resolution Microwave Spectroscopy of the10G−10HRydberg Transition inH2

Microwave resonance transitions between the $\mathrm{}(0,1)10G_5$ and $\mathrm{}(0,1)10H_6$ states of ${\mathrm{H}}_2$ have been observed with a fast-beam technique and have been used to determine an energy difference of 10 031.24(10) MHz between these two Rydberg states. The observations show partial resolution of the magnetic fine and hyperfine structure which appears to conform to a simple model. It should prove possible to deduce new precise information about the ${\mathrm{H}}_2^{+}$ ion from measurements of this type.