The Hyperfine Structure and Nuclear Moments of the Stable Chlorine Isotopes

The hyperfine structure of the ²P3/2 ground states of Cl³⁵ and Cl³⁷ is investigated by the atomic beam magnetic resonance method. Values of the magnetic dipole interaction constant, a, and the electric quadrupole interaction constant b are found to be a₃₅=205.288±0.010 Mc/sec., a₃₇=170.686±0.010 Mc/sec., b₃₅=55.347±0.020 Mc/sec., b₃₇=43.256±0.020 Mc/sec.No octupole interaction is required to account for the experimental results. A simple method is introduced for calculating accurate values of the electric quadrupole moments Q from these data and the corresponding values are Q₃₅=-(0.0795±0.0005)×10^-24 cm² and Q₃₇=-(0.0621±0.0005)×10^-24 cm².This method can be extended to many other cases for which the interaction constants a and b and the nuclear gyromagnetic ratio are known. Experimental details are given for the production and detection of beams of atomic chlorine.