Decay of the first triplet Kr2 excimer in the presence and absence of N2 and effects of N2 on the decay constant and excimer yield at 298 K

The optical absorbance of Kr2 (3∑+u)(1u,0−u) at 984 nm has been measured as a function of time at 250 to 1100 Torr in pure krypton and in the presence of N2 at 800 Torr of krypton at 298 K. The decay constant is given by 2.53 (±0.19)106+194(±84)PKr s−1 in the absence of N2. The rate constant for electronic quenching by N2 is 7.65(±0.34)10−12 cm3 s−1. All observations are consistent with the formation of a long-lived ‘‘bottleneck’’ species associated kinetically with the Kr(1s2) state as proposed by Bonifield et al. The bottleneck is essentially unaffected by the presence of N2 below 10 Torr. It is suggested that the bottleneck species is a bound molecular state which correlates with one of the Kr(2p) atomic states in the separated atom limit.