Electron drift and longitudinal diffusion in high pressure xenon-helium gas mixtures

• Published in: Journal of instrumentation Vol. 14; no. 8; p. P08009
• Main Authors: McDonald, A.D., Woodruff, K., Atoum, B. Al, González-Díaz, D., Jones, B.J.P., Adams, C., Álvarez, V., Arazi, L., Arnquist, I.J., Azevedo, C.D.R, Bailey, K., Ballester, F., Benlloch-Rodríguez, J.M., Borges, F.I.G.M., Cárcel, S., Carrión, J.V., Cebrián, S., Church, E., Conde, C.A.N., Díaz, G., Díaz, J., Diesburg, M., Escada, J., Esteve, R., Felkai, R., Fernandes, A.F.M., Fernandes, L.M.P., Ferrario, P., Ferreira, A.L., Freitas, E.D.C., Generowicz, J., Goldschmidt, A., Gómez-Cadenas, J.J., Guenette, R., Gutiérrez, R.M., Haefner, J., Hafidi, K., Hauptman, J., Henriques, C.A.O., Morata, J.A. Hernando, Herrero, P., Herrero, V., Johnston, S., Kekic, M., Labarga, L., Laing, A., Lebrun, P., López-March, N., Losada, M., Mano, R.D.P., Martín-Albo, J., Martínez, A., Martínez-Lema, G., Monrabal, F., Monteiro, C.M.B., Mora, F.J., Vidal, J. Muñoz, Novella, P., Nygren, D.R., Palmeiro, B., Para, A., Pérez, J., Querol, M., Renner, J., Repond, J., Riordan, S., Ripoll, L., Garcia, Y. Rodriguez, Rodríguez, J., Rogers, L., Romeo, B., Romo-Luque, C., Santos, F.P., Santos, J.M.F. dos, Simón, A., Sofka, C., Sorel, M., Stiegler, T., Toledo, J.F., Torrent, J., Usón, A., Veloso, J.F.C.A., Webb, R., Weiss-Babai, R., White, J.T., Yahlali, N.
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 01.08.2019; Institute of Physics (IOP)
• Subjects: Additives; charge transport and multiplication in gas; Diffusion; Diffusion coefficient; Drift; Electric fields; Gas mixtures; gaseous imaging and tracking detectors; Helium; Helium-Xenon; INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; NUCLEAR PHYSICS AND RADIATION PHYSICS
• ISSN: 1748-0221; 1748-0221
• DOI: 10.1088/1748-0221/14/08/P08009

We report new measurements of the drift velocity and longitudinal diffusion coefficients of electrons in pure xenon gas and in xenon-helium gas mixtures at 1-9 bar and electric field strengths of 50-300 V/cm. In pure xenon we find excellent agreement with world data at all E/P, for both drift velocity and diffusion coefficients. However, a larger value of the longitudinal diffusion coefficient than theoretical predictions is found at low E/P in pure xenon, below the range of reduced fields usually probed by TPC experiments. A similar effect is observed in xenon-helium gas mixtures at somewhat larger E/P. Drift velocities in xenon-helium mixtures are found to be theoretically well predicted. Although longitudinal diffusion in xenon-helium mixtures is found to be larger than anticipated, extrapolation based on the measured longitudinal diffusion coefficients suggest that the use of helium additives to reduce transverse diffusion in xenon gas remains a promising prospect.