Fine Structure of theN=1(1s3p)Πu3State of the Hydrogen Molecule Determined by Magnetic Resonance

Abstract

In the preceding paper some of our results on the magnetic-resonance experiments performed at 64 MHz indicated a beginning of N·S decoupling on the $N=1\mathrm{}$ $\mathrm{}\left(1s3p\right)\mathrm{}{}_{}{}^3{}_{}{}^{}\Pi _u^{}{}_{}{}^{}$ state of ${\mathrm{H}}_2$ excited by electron impact. In the present paper we present further results on the resonance experiments performed at higher frequencies in order to determine the fine structure of this level. Our findings indicate that the energy separation between $J=1\mathrm{}$ and $J=2\mathrm{}$ levels is 160±5 MHz and between $J=1\mathrm{}$ and $J=0\mathrm{}$ levels it is 2100±600 MHz, and in addition the former exhibits a small dependence on the vibrational number. The relative order of these levels is $J=1, 2, 0$ instead of the theoretically predicted 2, 1, 0. The Landé $g$ factor is 1.249±0.010, which corresponds to a pure Hund's-coupling case (b).