Angular Distribution of the Resonance Fluorescence Radiation from the 411-kev Excited State ofHg198

By using the Doppler broadening due to thermal agitation at elevated temperatures as a means of restoring the resonance condition, the angular distribution of the resonance fluorescence radiation from the 411-kev excited state in ${\mathrm{Hg}}^{198}$ has been measured. The observed distribution has the form $1+(0.37\pm 0.06)P_2\left(cos\theta \right)+(1.07\mathrm{}\pm 0.08)P_4\left(cos\theta \right),$ which agrees very well with the theoretical expectation for the excitation of a state with spin 2 from a ground state with spin 0.