MEASUREMENT OF TOWNSEND IONIZATION COEFFICIENTS AND THE BREAKDOWN POTENTIALS FOR THE PENNING MIXTURES OF NE AND KR

The Townsend primary (α) and secondary (γ) coefficients and Paschen curves for neon, krypton, and their mixtures are reported. The primary coefficient was determined by measuring the variation in the luminous flux in a self-sustained Townsend discharge between two parallel-plate nickel electrodes spaced 21.5 mm apart. The values for the reduced primary coefficient α/p0 for Ne and Kr are about 10-20% lower than the published values obtained by the classical method of Townsend. The α/p0 values for Ne agree with results of previous work using the same luminous-flux method. The ionization efficiency function η (η=α/E, where E is the electric field) for a Ne-Kr gas mixture has a maximum value (0.0040 V -1) for Ne admixed with 0.1% Kr.