The temperature dependence of the three-body reaction rate coefficient for some rare-gas atomic ion-atom reactions in the range 100-300K

The temperature dependence of some three-body association reaction rate coefficients for some rare-gas atomic ion-rare-gas atom reactions of the type A++2B to AB++B have been investigated in the temperature range 100-300K using a selected ion flow tube technique. The experimental method consists of injecting the ion A+ into the flowing carrier gas B and monitoring the ratio of the concentrations of AB+ to A+ as a function of carrier gas pressure. The three-body association rate coefficients are obtained from an analysis which allows for differential diffusive losses and reaction with impurities in a limited manner. The following results have been obtained (k3 in units of cm6 s-1): He++2He to He2++He K3=0.83*10-31(T/300)-0.6 (180<T<300); Ne++2He to NeHe++He k3=0.20*10-31(T/300)-1.6 (120<T<300); Ar++2Ar to Ar2++Ar k3=2.25*10-31(T/300)-0.4 (150<T<300); Kr++2Ar to ArKr++Ar k3=1.20*10-31(T/300)-1.3 (130<T<300).