Possible Effects of Nuclear Spin on X-Ray Terms

Abstract

It is shown that magnetic moments of nuclei are likely to cause small but presumably measurable separations of x-ray terms. A nucleus having a spin of 9/2 (in units of $\frac{h}{2\ensuremath{\pi}}$) and a magnetic moment 9/2 in protonic units should cause the $K$ terms of the heaviest elements to split into two components separated by about 22 volts. Such separations require for their detection a resolving power of 4200. For lighter elements the effect is relatively smaller. The same nuclear spin and magnetic moment would cause a separation of only 0.9 volts in Mo which would require for its detection a resolving power of 1.9\ifmmode\times\else\texttimes\fi{}${10}^{4}$The calculations are made using Dirac's equation for a single electron without approximations. The effect of electrons in another shell, however, is neglected. It is estimated to be very small for a single $K$ electron. If the observation of hyperfine structures in the $K$ series of the heavier elements proves feasible, it should offer a simple means of determining magnetic moments of nuclei having a known spin.