Operation of a Liquid Argon Time Projection Chamber
For the first time, the operation of a three-dimensional liquid argon time projection chamber has been demonstrated. This was accomplished in a 50 liter test detector using a readout plane with a woven structure etched on a PC-board.
Effects of oxygen and nitrogen on drifting electrons in a liquid argon TPC
Abstract The attenuation length of electrons drifting in liquid argon is examined as a function of electric drift field from 0.5 to 3.0 kV cm −1 , and of impurity level for low concentrations of oxygen (∼ ppb) and nitrogen (∼ ppm). Deviations from the “standard” formula are noted, possible explanations are discussed, and a new, semiempirical formula is proposed.
Dependence of Radiation‐Induced Conductance of Liquid Hydrocarbons on Molecular Structure
The radiolytic ion mobilities u, ion‐neutralization rate constant k, steady‐state radiation‐induced conductance κ, and free‐ion yield Gfi have been measured for a number of saturated hydrocarbon liquids of different molecular shape. The values of G>fi in the following liquids at 20° were; cyclohexane, 0.11; n‐hexane, 0.11; n‐pentane, 0.12; 2,2‐dimethylbutane, 0.40; 2,2‐dimethylpropane, 0.81. The unusually high values for the last two compounds were partly associated with a current “overshoot” that occurred at the beginning of current‐vs‐time oscillograms that were obtained for the evaluation of k / u. The overshoot was not present in oscillograms obtained from the first three liquids. The causes of the overshoot and the high Gfi values are not known, but their magnitudes correlate with the closeness to spherical shape of the molecules. The facility of electron trapping and of electron energy loss in the subvibrational‐excitation energy region are probably dependent on molecular shape and on liquid structu...