A radiation detector which employs an electric field for the collection at the electrodes of charges associated with the ions produced in the sensitive volume by ionizing radiation, without charge multiplication. The solid angle (2Π, 4π ) subtended when using the detector, is sometimes specified.
Source:
PAC, 1982, 54, 1533. 'Glossary of terms used in nuclear analytical chemistry (Provisional)' on page 1545 (https://doi.org/10.1351/pac198254081533)