de Urquijo J, Basurto E, Juárez A M, Ness K F, Robson R E, Brunger M J, White R D
Instituto de Ciencias Físicas, Universidad Nacional Autónoma de México, 62251, Cuernavaca, Mor., Mexico.
División de Ciencias Básicas e Ingeniería, Universidad Autónoma Metropolitana, Av. San Pablo 180, 02200, México, D.F.
J Chem Phys. 2014 Jul 7;141(1):014308. doi: 10.1063/1.4885357.
The drift velocity of electrons in mixtures of gaseous water and helium is measured over the range of reduced electric fields 0.1-300 Td using a pulsed-Townsend technique. Admixtures of 1% and 2% water to helium are found to produce negative differential conductivity (NDC), despite NDC being absent from the pure gases. The measured drift velocities are used as a further discriminative assessment on the accuracy and completeness of a recently proposed set of electron-water vapour cross-sections [K. F. Ness, R. E. Robson, M. J. Brunger, and R. D. White, J. Chem. Phys. 136, 024318 (2012)]. A refinement of the momentum transfer cross-section for electron-water vapour scattering is presented, which ensures self-consistency with the measured drift velocities in mixtures with helium to within approximately 5% over the range of reduced fields considered.
利用脉冲汤森技术，在0.1 - 300 Td的约化电场范围内，测量了气态水和氦气混合物中电子的漂移速度。发现向氦气中添加1%和2%的水会产生负微分电导率（NDC），尽管纯气体中不存在NDC。测量得到的漂移速度被用作对最近提出的一组电子 - 水蒸气截面[K. F. Ness, R. E. Robson, M. J. Brunger, and R. D. White, J. Chem. Phys. 136, 024318 (2012)]的准确性和完整性的进一步判别评估。提出了电子 - 水蒸气散射的动量转移截面的改进，这确保了在所考虑的约化电场范围内，与氦气混合物中测量的漂移速度的自洽性在约5%以内。
