Emission signals at 8758 A˚ were observed when bismuth atom vapor was introduced into a supersonic flow of electronically excited nitrogen fluoride, NF (a1&Dgr;). A correlation of thermal and pressure data with the appearance of the chemiluminescence, along with a computer analysis of the IRTV observations at two wavelengths, is presented. On the basis of an analysis of these data, it is concluded that the observed emission results from the production of an excited‐state bismuth atom density, Bi(2D3/2), on the order of >1013atoms cm−3by collisional transfer with NF (a1&Dgr;).