Drift Velocity of Free Electrons in Liquid Argon

A measurement of the drift velocity of free electrons in liquid argon has been performed. Free electrons have been produced by photoelectric effect using laser light in a so called "laser chamber". The results on the drift velocity v_d are given as a function of the electric field strength in the range 0.5 kV/cm < E < 12.6 kV/cm and the temperature in the range 87 K < T < 94 K. A global parametrization of vd_(E,T) has been fitted to the data. A temperature dependence of the electron drift velocity is observed, with a mean value of delta(v_d)/(delta(T) v_d) = (-1.72+/-0.08)%/K in the range of 87 - 94 K.