Doses Delivered to Thermoluminescence Detectors (TLDs) Due to Radon Gas
L.W. Parker; J.A. Moore; S.-H. Hsu; A.L. Lehnert; M.L. Rodrigues; and K.J. Kearfott (University of Michigan)
The purpose of this work is to quantify the dose delivered to thermoluminescent detectors (TLDs) in different configurations due to radon gas and explore a means of decreasing these doses. Research consists of exposing calibrated TLDs in different configurations to radon within a small chamber. The configurations of TLDs placed inside the radon chamber include bare TLD materials (chips), TLD chips stored in cards, TLD cards held in badge assemblies, and TLDs protected from radon exposure using various materials. A 250-liter radon chamber, a modified incubator that houses a Radon-226 source (a radium dial), is characterized using a radon monitor providing measurements of radon activity concentration as a function of time. The integral of the radon activity graph is representative of the total exposure to radon for a specified period of time. Measurements of ambient background radiation dose within the chamber are performed by placing TLDs inside the chamber when the Radon-226 source is not present. After subtracting for the non-radon background, the dose recorded on the TLDs is plotted as a function of integrated radon exposure. Comparisons are made of the doses per unit radon concentration for different TLD configurations. It is hoped that a standard process for correcting TLDs for doses due to radon gas and that strategies for minimizing these will be possible.