Hyperfine Structure, Isotopic Level Shifts, and Pressure Self-Broadening of the 72P States of Natural Thallium by Doppler-Free Two-Photon Absorption.

摘要

The hyperfine constants, isotopic level shifts, and a pressure self-broadening constant of the 72P states of 203,205 Tl have been measured by the Doppler-free two-photon absorption technique. This hyperfine constant of the 72P(3/2) state is found to be greater than that of the 62P (3/2) state. This anomaly is tentatively attributed to a sign change in the promoted core s-electron spin-polarization contribution to the hfs as calculated by Fermi and Segre for the 62P(3/2) state. The isotope shift of the 72P(1/2) state is 20% smaller than that of the 72P(3/2) state, confirming the nuclear volume effect of the P(1/2) electron. At higher pressures line broadening is observed as the Tl density is increased. (Author)