Lifetimes andgJFactors in Excited States of Chromium. Hyperfine Structure ofCr53

The ${}_{}{}^7{}_{}{}^{}P$ terms of two excited chromium configurations have been studied by the techniques of level-crossing and double-resonance spectroscopy. The lifetimes of the $J$ levels of the two terms were found by observation of the Hanle effect to be (3.34±0.5) × ${10}^{-8\mathrm{}}$ sec and (6.51±0.9) × ${10}^{-9\mathrm{}}$ sec for $\left(3\mathrm{}{d}^{5}4p\right){}_{}{}^7{}_{}{}^{}P_4^{}{}_{}{}^{}$ and $\left(3\mathrm{}{d}^{4}4s4p\right){}_{}{}^7{}_{}{}^{}P_4^{}{}_{}{}^{}$, respectively. $g_J$ values for the three $J$ levels of the $\left(3\mathrm{}{d}^{5}4p\right){}_{}{}^7{}_{}{}^{}P$ term were also determined: $g(J=4\mathrm{})=1.7512\mathrm{}\left(3\right)\mathrm{}$, $g(J=3\mathrm{})=1.9178\mathrm{}\left(2\right)\mathrm{}$, and $g(J=2\mathrm{})=2.3351\mathrm{}\left(3\right)\mathrm{}$. For the purpose of studying core polarization in chromium, measurements were made of the magnetic hyperfine constants in both configurations. For $3d^{5}4p$, $\mathrm{}\left|a\right(J=4\mathrm{}\left)\right|=11.6\mathrm{}\pm 0.15$ Mc/sec, $\mathrm{}\left|a\right(J=3\mathrm{}\left)\right|\le 1.5\pm 2.0$ Mc/sec, $\mathrm{}\left|a\right(J=2\mathrm{}\left)\right|=26.16\mathrm{}\pm 0.10$ Mc/sec, and for $3d^{4}4s4p$, $\mathrm{}\left|a\right(J=3\mathrm{}\left)\right|=70.4\mathrm{}\pm 2.6$ Mc/sec.