GB1253495A - Portable detector for measuring ionizing radiation - Google Patents

Abstract

1,253,495. Radiation detector. COMMISSARIAT A L'ENERGIE ATOMIQUE. Feb.5, 1970 [Feb.18, 1969J, No.5568/70. Heading G1Q. In a portable detector for measuring ionizing radiations, especially X and γ radiation, an electro-scope 22-26 is mounted on the nosepiece 24 of a microscope 18. The microscope, electroscope and an end-cap 34, 36, 38 via which the electro-scope is charged, are disposed in end to end relation within a container 10, the electroscope being mounted within an ionization chamber limited by a thin leak tight wall 40. A sleeve 46 having a calibrated thickness is displaceably mounted in the container so as to be able to cover the thin wall or to be withdrawn therefrom. The material and thickness of the thin wall are chosen so that the detector has a response corresponding to a protection of 7mg/cm<SP>2</SP> of human tissues (i.e. eye tissue), while the sleeve is such that the response corresponds to an absorbtion by 300mg/cm<SP>2</SP> of tissues when the sleeve covers the wall. The miscroscope has two differently calibrated measuring scales for the two sleeve positions. The microscope casing is joined to the end-cap structure by thin arms around the thin wall. The electrometer may consist of a movable metallized quartz fibre 26 bonded to a U-shaped stationary copper bow 22. The electrometer can be charged by connecting a voltage to the rod 36 and pressing it so that the bellows 38 expand and make contact with the connector rod 28 connected to the bow 22. The movement with time of the wire as the electrometer discharges when subjected to ionizing radiation is observed in the microscope.