EFFECT OF TEMPERATURE ON THE ATTACHMENT OF SLOW (LESS-THAN-OR-EQUAL-TO-1 EV) ELECTRONS TO CH3BR

The electron attachment rate constant k(a)([is-an-element-of], T) for CH3Br has been measured in a buffer gas of N2 using a high pressure electron swarm apparatus, within the mean electron energy range from thermal (approximately 0.046 eV) to 0.87 eV and over the temperature range, T, 300-700 K. At room temperature, CH3Br attaches low energy electrons weakly but as T is raised from 300 to 700 K the total electron attachment cross section increases by more than 2 orders of magnitude. At T=300 K the electron attachment cross section exhibits a peak at 0.38 eV which shifts progressively to lower electron energies as Tis increased. The thermal value of k(a) is 1.08 X 10(-11) cm3 s-1 at 300 K and 3.2 8 X 10(-9) cm3 s-1 at 700 K.