SCINTILLATIONSREKNARE MED EN REKNEKAMMARE I ETT STRALNINGSAVSKERMANDE HOLJE

摘要

A light seal for the counting chamber of a scintillation counter comprises a ring shutter mounted in the shielded housing which forms the counting chamber. The ring shutter is mounted for rotation between an open position where an aperture in the ring shutter is aligned with an opening into the shielding housing to permit transfer of sample vials in and out of the counting chamber, and a closed position where a shroud portion of the shutter covers the opening in the housing to block the entry of light. The ring shutter closely surrounds the sample vial in the counting chamber and is preferably formed of a radiation shielding material. The shroud portion of the ring shutter includes a cam for engaging a sample vial disposed within the shutter aperture when the shutter rotates from the open position to the closed position, for lifting the sample vial to a predetermined elevation within the counting chamber. A reflector disposed within the counting chamber cooperates with the cam portion of the shutter for laterally positioning the sample vial within the counting chamber.