Zeeman Effect in the Arc Spectrum of Cobalt

Zeeman patterns for 151 lines in the range $\lambda 3200 \mathrm{to} \lambda 6500$ are measured and $g$-factors for 100 terms are determined. All the experimental $g$-factors are compared with their theoretical values for $\mathrm{LS}$ coupling and those for the deep even terms are compared with theoretical values for intermediate coupling. The experimental values for the multiplets, $b^{4}P$, $a^{2}D$, $m^2{D}^{\circ }$, $y^4{F}^{\circ }$ and $m^2{P}^{\circ }$ deviate rather widely from the theoretical values. The Zeeman patterns indicate changes in classifications for $\lambda 4549.67$ and $\lambda 6450.24$ and decide the quantum numbers for two incompletely analyzed terms.