NF3 DECOMPOSITION BEHIND SHOCK-WAVES

The rate constant of the NF3 dissociation reaction in a helium mixture in the low-pressure limit was directly measured in a shock tube by a UV absorption method. The rate constant may be expressed as K = 10(14.38 +/- 0.07) exp{-[36600 +/- 2200 (cal/mol)]/RT} cm3/mol s in the temperature range 1050-1600 K. Levels of the NF3 stationary dissociation fraction were also measured as a function of the initial temperature of the mixture behind the shock wave. It increases monotonically with temperature and reaches 50% of the value at 1600 K, which corresponds to high NF2 concentration up to 2 x 10(17) cm-3.