Hyperfine-Structure Separations, Isotope Shifts, and Nuclear Magnetic Moments of the Radioactive Isotopes Tl^199, Tl^200, Tl^201, Tl^202, and Tl^204

Abstract

The hyperfine structure and isotope shift of five radioactive isotopes of thallium have been measured spectroscopically. Thallium-199 (7.4 hr) and thallium-200 (27 hr) were produced by alpha bombardment of gold; thallium-201 (3 day), thallium-202 (12 day), and thallium-204 (4 year) were produced by deuteron bombardment of liquid mercury. The isotopes were excited in electrodeless-discharge lamps. Approximately 0.001 μg of radio-thallium was used in the lamps. The hfs splittings and isotope shifts in the 62P12,62P32, and 72S12 states were obtained by using a 10-in. plane diffraction grating in autocollimation in a 40-ft mirror monochromator. Previously measured values of the nuclear spins of the odd-even isotopes have been verified. Nuclear magnetic moments or upper limits on the moments have been calculated by comparison of the hyperfine splittings of the radioactive isotopes with the known splittings and moments of the stable thallium isotopes. A definite dependence of the relative isotope shifts on neutron number was observed.