Attachment and diffusion of thermal electrons in methyl bromide

The Cavalleri electron density sampling technique (1969) has been used to measure the rate of loss of thermal electrons in mixtures of CH3Br and H2 at temperatures in the range 293-500 K. From these data attachment coefficients for thermal electrons in CH3Br have been derived with an uncertainty of less than +or-4% enabling the temperature dependence and activation energy to be determined. In addition the diffusion coefficient for thermal electrons in CH3Br at room temperature has been determined from which an estimate of the e--CH3Br momentum transfer cross section has been made for energies less than 100 meV.