Comparison of Measured Dose Enhancement Effects in LiF TLDs with 2-D Monte Carlo Predictions

Relative-dose-enhancement factors in LiF dosimeters were measured as a function of spacing between the dosimeters and an Al-Au bilaminate filter in a bremsstrahlung spectrum of 145 keV average energy. Results essentially agree with 2-D Monte Carlo code predictions. However, the calculated results may be somewhat greater than the experimental results at zero bilaminate spacing. 2-D effects were found to be significant at 1.9cm bilaminate spacing. A 40 micron thick Al foil interposed between the bilaminate and the dosimeters reduced dose enhancement by approximately a factor of 10.