K-Shell Internal Conversion Coefficients

Internal conversion coefficients for the $K$-shells of several medium-energy gamma emitters have been measured with a solenoidal beta spectrometer and a 30 mg/${\mathrm{cm}}^2$ lead radiator. Isotopes investigated, with gamma energies and conversion coefficients ×${10}^3$, are as follows: ${\mathrm{Nb}}^{95}$, 722 kev, 1.6±0.8; ${\mathrm{Cd}}^{110}$, 657 kev, 2.2±0.8; ${\mathrm{Te}}^{122}$, 570 kev, 6.6±1.7; ${\mathrm{La}}^{140}$, 541 kev, 5.6±1.9; ${\mathrm{Ce}}^{140}$, 489, 5.3±2.0. These values lead to multipolarity assignments of $E2\mathrm{}$ or $M1\mathrm{}$ for the first three, $E2\mathrm{}$ for the ${\mathrm{La}}^{140}$, and $E1\mathrm{}$ or $E2\mathrm{}$ for the ${\mathrm{Ce}}^{140}$.