γ線による絶縁性液体の電離

抄録

Some characteristics of ionization phenomena in dielectric liquids irradiated by gamma-rays from ⁶⁰Co were studied. Ionization current was measured with a parallel plate ionization chamber. In the chamber, not only the field intensity, but also the electrode spacing could be changed independently.
Applying Jaffé's theory on columnar recombination to the obtained characteristic curve of ionization, the saturated value of ionization current was estimated. The collection efficiencies for ions in several kinds of dielectric liquids were studied as a function of field intensity.
The average energy per ion pair, W-value, for several kinds of dielectric liquids was esti-mated from the value of the saturation current from which the influence of secondary elect-rons emitted from the chamber wall was excluded. Using the W-value of carbon disulphide measured by Mohler and Taylor as the relative standard, the following W-value for dielectric liquids were obtained; n-hexane 25eV; cyclohexane 22eV; iso-octane 22eV; toluene 93eV; carbon tetrachloride 54eV; tetrachloroethylene 56eV.