W-VALUE IN LIQUID KRYPTON

The W value, or the average energy required to produce an electron-ion pair, was measured in liquid krypton with a pulsed ionization chamber and Bi-207 976-keV internal-conversion electrons. From the charge col lected at the highest electric field of 16 kV/cm, the W value was dete rmined to be 18.4+/-0.3 eV. Extrapolation of the charge to infinite fi eld strength yields a smaller W value, reduced by an amount which depe nds on the recombination model used to fit the data. The delta-electro n model gives the lowest value of 16.8 eV. An estimation of the W valu e in liquid krypton, using Platzman's energy-balance equation, is in g ood agreement with the experimental result, but is not precise enough to rule out model-dependent lower values.