The Basic Design Data of a Guarded-field Thimble Ionization Chamber: A Theoretical Investigation

A mathematical investigation of the electrostatic field configuration inside a guarded-field ionization chamber is described. The basic design data for this type of chamber are derived and shown to be in good agreement with the previously obtained experimental design data. Also, the theory provides an extension of the experimental data where, on the one hand the collecting electrode is vanishingly small and on the other hand, where the ratio of the collecting electrode radius to the internal radius of the chamber approaches unity.