We report the measurement of longitudinal electron diffusion coefficients in liquid argon for electric fields between 100 and 2000 V/cm with a gold photocathode as a bright electron source. The measurement principle, apparatus, and data analysis are described. In the region between 100 and 350 V/cm, our results show a discrepancy with the previous measurement . In the region between 350 and 2000 V/cm, our results represent the worlds best measurement. Over the entire measured electric field range, our results are systematically higher than the calculation of Atrazhev-Timoshkin . The quantum efficiency of the gold photocathode, the drift velocity and longitudinal diffusion coefficients in gas argon are also presented.
Li, Y., Tsang, T., Thorn, C., Qian, X., Diwan, M., Joshi, J., … Viren, B. (2016). Measurement of longitudinal electron diffusion in liquid argon. Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 816, 160–170. https://doi.org/10.1016/j.nima.2016.01.094