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The absolute values of the neutrino masses are important to the evolving models of particle physics, and cosmology. Experimental limits on the neutrino masses have been established by neutrino oscillation and nuclear beta decay experiments. Improved, model dependent limits are being provided by a range of cosmological observations and neutrinoless double beta decay experiments. This document reports on the status of experiments investigating neutrino mass in a direct, model independent, way. These experiments are approaching a sensitivity that will offer guidance and constraint to models of both cosmology and particle physics. The prospect for pushing the sensitivity of direct measurements still further is considered. [Copyright &y& Elsevier]

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.