INVESTIGATION OF THE CHARACTERISTICS OF A SPHERICAL SINGLE-WIRE PROPORTIONAL COUNTER USED FOR EXPERIMENTAL MICRODOSIMETRY.

The resolution of a commercially available spherical single-wire tissue equivalent proportional counter has been investigated in order to establish if the design criteria of Benjamin et al. for a single-wire spherical neutron spectrometer also applies when used in the construction of a counter for microdosimetric measurements. The result indicate that the volume-averaged fractional electric field distortion due to using a single wire in a spherical geometry is about 1% and close to the value found by Benjamin et al. By using an alpha particle probe at different orientations and changing the anode wire it is shown that there is variation of field distortion along the anode wire, but that the choice of anode wire diameter is not as critical as suggested by the Benjamin design.