Low-energy electron collision cross sections of ethane by electron swarm study

Abstract

The drift velocity and the longitudinal diffusion coefficient of electrons in 0.206% and 1.98% ethane - argon mixtures and in pure ethane were measured in the E/N ranges 0.03 - 3 Td, 0.03 - 25 Td and 0.03 - 300 Td respectively. The measured swarm parameters in the mixtures were used to determine the essential vibrational excitation cross sections of the ethane molecule and those measured in pure ethane were used to derive the elastic momentum transfer cross section for the molecule in conjunction with the above derived vibrational cross sections. Consideration of realistic anisotropies of the electron scattering had little effect on electron swarm parameters.

Study of electron transport in hydrocarbon gases

“…Figure 2 shows the drift velocities for C 2 H 2 , C 2 H 4 , and C 2 H 6 in comparison with the data found in the literatures. [8][9][10][11][12] Our present results are in good agreement with those from other investigations from 300 to 1000 Td. To the best of our knowledge, the drift velocities in these gases for E/N above 1000 Td have been measured for the first time in this study.…”

“…4 can be interpreted from a view point of the electron collision cross sections, namely, the initial rise of the ionization cross section for C 2 H 6 at the energy just above the ionization threshold is the largest, while the momentum transfer cross section is the smallest among the three molecules. 10,12,20 Although the swarm parameters sometimes differ depending on their definitions, particularly at the high E/N region in which the ionization process can occur (e.g., Ref. 4), the exact definition of some parameters and their measurement methods have been established.…”

Analytic Cross Sections for Electron Collisions With Hydrocarbons: Ch4, C2h6, C2h4, C2h2, C3h8, and C3h6

“…They estimated the value at zero energy to be 3.2 × 10 −15 cm 2 . The two sets of momentum transfer cross sections (Graph 44) are in fairly good agreement with each other at energies around 0.1 eV, but the result of Shishikura et al [32] seems to be too high at the lower energies. In the lower energy range, only the result of Merz and Linder [31] has been adopted.…”

“…However, considering the uncertainty of the latter, there is no inconsistency between the two cross sections. Shishikura et al [32] analyzed a swarm experiment and derived the momentum transfer cross section in the range 0.1-100 eV. Merz and Linder [31] also derived the momentum transfer cross section with the phase shift determined from their elastic cross section measured and using the modified effective range theory.…”

Electron Collision Cross Sections for C₃F₈ Molecule from Electron Transport Coefficients in C₃F₈-Ar Mixtures

“…Our principal scheme is, firstly, to study low energy inelastic cross sections of the molecule from transport coefficients in the mixtures and, secondary, to study the elastic momentum transfer cross section of the molecule from transport coefficients in pure molecular gas with using the inelastic cross sections studied in the first step. The scheme has worked successfully so far for a number of molecules including CO2 (5) and C2H6 (6).…”