Level-crossing study of the hyperfine structure of lithium

Abstract

The method of level-crossing spectroscopy has been employed to measure the hyperfine interaction constants and the lifetimes of the 2P2 and 3P2 states of Li7. The parameters for the P32 states were obtained from a conventional level-crossing experiment; it was also possible to measure the magnetic dipole hyperfine structure constant A for P12 states by using a newer method (similar to level crossing) called the "decoupling" method. With these techniques, it was possible to measure A for the 2P322, 3P322, and 3P122 states of Li7. These measurements, together with the measurement of B for the 3P322 state, made it possible to infer the nuclear quadrupole moment of Li7. In order to check the consistency of the A values obtained from the decoupling runs, data were taken (using the decoupling method) for A for the 2P122 and 3P122 states of Li6. In addition to the hyperfine data, the lifetimes for the 2P2 and 3P2 states were also obtained. The results are: A32(Li72P2)=-2.95(4) MHz, A32(Li7 3P2)=-1.036(16) MHz, A12(Li7 3P2)=13.7(12) MHz, A12(Li6 3P2)=5.3(4) MHz, A12(Li6 2P2)=17.8(3) MHz, B(Li7 3P2)=-0.094(10) MHz, τ(2P2)=26.4(8) nsec, τ(3P2)=203(8) nsec, and Q(Li7)=-59(8) mb. © 1978 The American Physical Society.