Scattering Cross Sections of Argon and Atomic Oxygen to Thermal Electrons

Abstract

the Ramsauer-Townsend minimum in the momentumtransfer cross section. Hence, the total cross section in the neighborhood of the minimum is given by the P-wave phase shift while the momentum-transfer cross section is approximately given by the difference between the P-and D-wave phase shifts. Therefore, one would expect the minimum momentum-transfer cross section to lie deeper than the minimum total cross section. The fact that the results of Frost and Phelps 16 did not find such a deep Ramsauer-Townsend minimum must be attributed to their necessarily broad distribution of electron energies.In the case of argon, where there is a strong energy dependence of the cross section, it is quite clear that a much better measure of the momentum-transfer *

Low-energy elastic scattering of electrons from atomic oxygen

“…The only measurement of total scattering cross sections is by Neynaber et a1 (1961) from 2.3 to 11.6 eV. Momentum transfer cross sections have been measured by Sunshine et a1 (1967) using the atomic beam recoil method from 0.5 to 11.3 eV, Lin and Kivel (1959) at 4000 K using a microwave absorption method and Daiber and Waldron (1966) using a shock tube method. These measurements were significant experimental achievements at their time.…”

Elastic Scattering from Atomic Oxygen and Photodetachment fromO−

“…Another experiment which used shock tube methods was reported by Daiber and Waldron. 31 They obtained cross sections which varied from 9X 10~1 6 cm 2 to 17X 10~~1 6 cm 2 in the energy range 0.43-0.49 eV.…”