Comparison of Burlin cavity theory with LiF TLD measurements for cobalt-60 gamma rays

Publisher Website
Google Scholar
Abstract
Co-60 .gamma.-ray absorbed dose were measured using LiF thermoluminescent (TL) dosemeters to obtain additional insight into cavity theory as applied to dosemeters of a size intermediate relative to the range of secondary electrons. Stacks of dosemeters (0.4 mm .RTM. 3 mm .RTM. 3 mm, hot-pressed LiF TLD-100) were surrounded by homogeneous LiF, polystyrene, Al, Cu or Pb. The absorbed dose in the stack (0.1-0.7 g/cm2 thick) was derived from TL readings of the individual dosemeters and was compared with calculations based on the Burlin cavity theory. A relatively strong asymmetry in the absorbed-dose distribution was found between the front, rear and middle dosemeters of the stack, especially when Pb was the surrounding medium. The cavity theory agreed well with results in polystyrene, but overestimated the dose in the LiF dosemeters enclosed in Al, Cu, and Pb. The general trend predicted by the Burlin theory is somewhat steeper relative to cavity size than observed. The theory was modified to make it more applicable to the dose at the center of the stack. For Pb this modification agreed more closely than the conventional theory.

This publication has 9 references indexed in Scilit: