Methodology for checking the stability of the Cesium-137 irradiator system of the Radiation Monitors Calibration Laboratory (LabCal) at IDQBRN / Metodologia para verificar a estabilidade do sistema de irradiação Césio-137 do Laboratório de Calibração de Monitores de Radiação (LabCal) no IDQBRN

Abstract

The provision for the Brazilian Army of equipment that provides reliable and safe measurements leads to the need for a metrology study of the calibration system used in the Institute's Radiation Monitor Calibration Laboratory (LabCal) of Chemical, Biological, Radiological and Nuclear Defense (IDQBRN). In order to verify the stability of dosimetry in Cesium-137, the ambient dose equivalent rate, H*(10), was experimentally obtained for certain distance settings and lead attenuators at different dates in order to compare them. To this end, the distance between the source of Cesium-137 and the ionization chamber was varied from 1000, 2000 and 3000 mm without attenuator and with lead attenuators with 15 and 32 mm. In this work, the reproducibility of the system was analyzed by comparing the scenario of equal distance and attenuator, but with a different test date. For this purpose, the correction due to the radioactive decay of the source up to a reference date was used for comparison.Furthermore,the stability of the LabCal in Cesium-137 was verified in the light of the relevant standards for exposures without attenuators and with select attenuators for the tested distances.