Transport coefficients and cross sections for electrons in water vapour: Comparison of cross section sets using an improved Boltzmann equation solution

Abstract

This paper revisits the issues surrounding computation of electron transport properties in water vapour as a function of E/n0 (the ratio of the applied electric field to the water vapour number density) up to 1200 Td. We solve the Boltzmann equation using an improved version of the code of Ness and Robson [Phys. Rev. A 38, 1446 (1988)], facilitating the calculation of transport coefficients to a considerably higher degree of accuracy. This allows a correspondingly more discriminating test of the various electron–water vapour cross section sets proposed by a number of authors, which has become an important issue as such sets are now being applied to study electron driven processes in atmospheric phenomena [P. Thorn, L. Campbell, and M. Brunger, PMC Physics B 2, 1 (2009)] and in modeling charged particle tracks in matter [A. Munoz, F. Blanco, G. Garcia, P. A. Thorn, M. J. Brunger, J. P. Sullivan, and S. J. Buckman, Int. J. Mass Spectrom. 277, 175 (2008)].

Integral cross sections for electron impact excitation of vibrational and electronic states in phenol

“…1 are the threshold energies for each of the composite vibrational-modes investigated. 21 Threshold energies are important quantities in simulation studies [11][12][13][14][15][16][17][18] and as such are denoted here for information purposes. It is clear that the ICS energy dependencies, for each of the modes, are very similar, to within the errors quoted.…”

“…21,23 Nonetheless, when simulating atmospheric plasma behaviour, etc., it is actually the integral cross sections (ICSs) (and the momentum transfer cross section) that are of most relevance to the modelling communities. [11][12][13][14][15][16][17][18] As a consequence, in this short paper, we report on our derivation of vibrational-mode and electronicstate ICSs from our previously published differential cross section measurements. 21,22 Phenol also possesses a range of physico-chemical properties which, from our experience with other collision systems, [24][25][26][27][28][29][30] are anticipated to play important roles in its scattering dynamics.…”

“…5,6 Plasmas have, therefore, also been investigated to remove phenolic based species from wastewater as a remediation strategy. [7][8][9][10] In order to gain a fundamental understanding for the utility of atmospheric plasmas to economically produce bio-fuels and other useful chemicals, or degrading toxic compounds, plasma simulations incorporating complete cross section databases (in fact, this is true in modelling most phenomena [11][12][13][14][15][16][17][18] ) are required. To this end, we have conducted a series of joint experimental and theoretical studies looking at the behaviour of electron-phenol scattering processes.…”

The electron-furfural scattering dynamics for 63 energetically open electronic states

“…[4][5][6][7][8] The present submission is a new step in this series of investigations with furfural, and as it is the integral cross sections (ICSs) that are generally of most interest to the modelling communities [9][10][11][12][13][14] it therefore represents an important achievement. Note that this follows on from a similarly extensive study on phenol, [15][16][17][18][19][20] another important by-product from the application of atmosphericpressure plasmas to biomass.…”

Differential cross sections for the electron impact excitation of pyrimidine

“…being evaluated in gaseous or bulk water. [4][5][6] To further improve models of radiation damage of biological systems it is desirable to include a more accurate description of the biological media that goes beyond water, such as including contributions from DNA analogs. However, this requires an accurate knowledge of the low-energy electron scattering phenomena from the constituent biomolecules.…”