Ground-State Hyperfine Structure and Nuclear Magnetic Moment of Thulium-169

The hyperfine structure of the $4f^{13}6s^2{}_{}{}^2{}_{}{}^{}F_{\frac{7}{2}}^{}{}_{}{}^{}$ ground state of ${\mathrm{Tm}}^{169}$ has been studied by means of the atomic-beam magnetic-resonance method. By the use of multiple transitions, measurements were made from which the nuclear magnetic moment could be extracted without the use of approximate wave functions. Computer analysis of the experimental data gives the following results: $A=-374.1374\mathrm{}\pm 0.0016$ Mc/sec; $g_J=-1.14119\mathrm{}\pm 0.00004$; ${g_I}^{\prime }=-(2.478\mathrm{}\pm 0.032)\times {10}^{-4\mathrm{}}$ (with ${\mu }_I$ expressed in Bohr magnetons); whence ${\mu }_I=-(0.229\mathrm{}\pm 0.003)$ nm (corrected for the diamagnetic shielding effect of the electrons).