Microwave Zeeman Spectrum of Atomic Chlorine

Abstract

The microwave spectrum of atomic chlorine has been observed at 9190 Mc/sec in the products of an rf electrodeless discharge. Of the twelve allowed transitions per isotope, $\ensuremath{\Delta}{M}_{I}=0$, $\ensuremath{\Delta}M=\ifmmode\pm\else\textpm\fi{}1$, five arising from ${\mathrm{Cl}}^{35}$ and two from ${\mathrm{Cl}}^{37}$ have been measured. Using a nonrelativistic Hamiltonian, analysis of the data yields $\ensuremath{-}\frac{{g}_{J}(\mathrm{Cl}; ^{2}P_{\frac{3}{2}})}{{g}_{p}}=438.50415\ifmmode\pm\else\textpm\fi{}0.00063$, where ${g}_{p}$ is the proton gyromagnetic ratio in a cylindrical sample of mineral oil. This result can be transformed to $\frac{{g}_{J}(\mathrm{Cl}; ^{2}P_{\frac{3}{2}})}{{g}_{J}(\mathrm{D})}=0.666201\ifmmode\pm\else\textpm\fi{}0.000002$. A calculation of the ${g}_{J}(\mathrm{Cl})$-isotope effect shows that it should not be observable in the present experiment. Estimates of the atom-atom and atom-molecule hard-sphere collision cross sections are made from measurements of linewidth and line intensity.