Fine Structure of the2P3and3P3States in Helium

Abstract

The $2{}_{}{}^3{}_{}{}^{}P_2^{}{}_{}{}^{}-2\mathrm{}{}_{}{}^3{}_{}{}^{}P_1^{}{}_{}{}^{}$, $3{}_{}{}^3{}_{}{}^{}P_1^{}{}_{}{}^{}-3\mathrm{}{}_{}{}^3{}_{}{}^{}P_0^{}{}_{}{}^{}$ and $3{}_{}{}^3{}_{}{}^{}P_2^{}{}_{}{}^{}-3\mathrm{}{}_{}{}^3{}_{}{}^{}P_1^{}{}_{}{}^{}$ level separations in orthohelium are determined experimentally by extending previously developed microwave-optical techniques. Frequencies of 2291.72±0.36 Mc/sec, 8113.78±0.22 Mc/sec, and 658.55±0.15 Mc/sec, respectively, are found for the above level separations. These results are to be compared with previous optical measurements of 2295±21 Mc/sec for $2{}_{}{}^3{}_{}{}^{}P_2^{}{}_{}{}^{}-2\mathrm{}{}_{}{}^3{}_{}{}^{}P_1^{}{}_{}{}^{}$, 7950±600 Mc/sec for $3{}_{}{}^3{}_{}{}^{}P_1^{}{}_{}{}^{}-3\mathrm{}{}_{}{}^3{}_{}{}^{}P_0^{}{}_{}{}^{}$, and a microwave-optical determination of 658±1 Mc/sec for $3{}_{}{}^3{}_{}{}^{}P_2^{}{}_{}{}^{}-3\mathrm{}{}_{}{}^3{}_{}{}^{}P_1^{}{}_{}{}^{}$.