Structure of the Helium Arc Line 3888

The helium arc line $(1s2s{}_{}{}^3{}_{}{}^{}S_1^{}{}_{}{}^{}-1s3p{}_{}{}^3{}_{}{}^{}P_{ 0,1,2}^{\circ }{}_{}{}^{})3888\mathrm{}\mathrm{A}$, has been examined for structure and has been resolved into the three components which are predicted by theory. The $1s3p{}_{}{}^3{}_{}{}^{}P_{ 0,1,2}^{\circ }{}_{}{}^{}$ levels are inverted which is in agreement with previous results for the $1s2p{}_{}{}^3{}_{}{}^{}P_{ 0,1,2}^{\circ }{}_{}{}^{}$ levels. The frequency differences in the present case are: ${\nu }_{0,1}=0.192\mathrm{} {\mathrm{cm}}^{-1\mathrm{}}, {\nu }_{1,2}=0.165\mathrm{} {\mathrm{cm}}^{-1\mathrm{}}.$