Magnetic Moments and HyperfineStructure Anomalies of Cs^{133}, Cs^{134}, Cs^{135}, and Cs^{137}
Abstract
The atomicbeam magneticresonance method was used to measure the nuclear gyromagnetic ratios and hyperfinestructure separations of the radioactive isotopes Cs^{134}, Cs^{135}, and Cs^{137}. A surface ionization detector was used. The hyperfinestructure separations were obtained by direct ΔF=+/1 transitions near zero field. The values of Δν found for the three isotopes are: Δν(Cs^{134})=10 473.626+/0.015 Mc/, Δν(Cs^{135})=9 724.023+/0.015 Mc/, Δν(Cs^{137})=10 115.527+/0.015 Mc/. Pairs of transition belonging to the two different Fstates, but involving the same m_{F} values, constitute frequency doublets separated by 2g_{I}μ_{0}H. From measurements of the difference frequencies of these doublets for pairs of isotopes in fields in the vicinity of 9000 gauss, the following gvalue ratios were obtained: g_{I}(Cs^{135})g_{I}(Cs^{133})=1.05820+/0.00008, g_{I}(Cs^{137})g_{I}(Cs^{135})=1.04005+/0.00008, g_{I}(Cs^{134})g_{I}(Cs^{133})=1.01447+/0.00029. The hfs anomalies arising from the variation of the electron wave function over the finite distribution of nuclear magnetization were calculated from these measurements. The values found for these anomalies, defined by ɛ_{2} ɛ_{1}=[g_{1}Δν_{2}(2I_{1}+1)][g_{2}Δν_{1}×(2I_{2}+1)] 1, are: ɛ(Cs^{133})ɛ(Cs^{135})=+0.037+/0.009%, ɛ(Cs^{135})ɛ(Cs^{137})=0.020+/0.009%, ɛ(Cs^{133})ɛ(Cs^{134})=+0.169+/0.030%. The theory of Bohr and Weisskopf on the hfs anomalies was applied to these nuclei; the calculations are based primarily on a singleparticle model with varying distributions of spin and orbital contribution to the nuclear moment. An apparent magic number effect in the anomalies was observed.
 Publication:

Physical Review
 Pub Date:
 January 1957
 DOI:
 10.1103/PhysRev.105.590
 Bibcode:
 1957PhRv..105..590S