Electron Scattering in Methane, Acetylene and Ethylene

The scattering coefficients for elastic collisions between electrons and molecules of methane, acetylene and ethylene have been measured over the following ranges: for C${\mathrm{H}}_4$, 10 to 625 volts, 10 to 150 deg., and for 800 volts, 10 to 50 deg.: for ${\mathrm{C}}_2$ ${\mathrm{H}}_2$, 10 to 100 volts, 10 to 150 deg.; for ${\mathrm{C}}_2$ ${\mathrm{H}}_4$, 10 to 225 volts, 10 to 150 deg. Total absorption coefficients due to elastic scattering were computed by integration. For 100 volts and above, the scattering coefficients of electrons by the molecules with two C atoms were far smaller than the coefficient for C${\mathrm{H}}_4$ with one C atom, but for 10 volt electrons the scattering was much less in C${\mathrm{H}}_4$ than in the other two gases.