MEASUREMENT OF ELECTRON-DRIFT PARAMETERS FOR HELIUM AND CF4-BASED GASES

We have studied various helium and CF4-based gas mixtures, which may have important applications for the SSC, Phi, Tau-charm, and B factories. We present an integrated set of measurements, which includes the drift velocity, longitudinal single electron diffusion, characteristic electron energy, single electron pulse height spectra, operating wire gain, relative cathodic breakdowns in different gases, effect of water addition on the drift parameters, impurity problems in the CF4-based gases, diffusion near the wire and wire aging. The data are compared to predictions based on electron transport theories.