Photon yields and spectra resulting from reactions of Ca with oxidants

Calcium atoms have been reacted with various oxidants to produce chemiluminescence of CaO, CaBr, CaCl, and CaF. Spectra of the flames were recorded, and photon yields were measured for the reactions. Photon yields of CaO at 1.2 torr vary from 6.0×10−2 for Ca+O3 to 0.04×10−2 for Ca+NO2. Ca+F2 gives yields as high as 0.9×10−2, while Cl2 and Br2 are considerably less efficient as oxidants.