The response of thermoluminescent dosimetric lithium borates equivalent to air, water and soft tissue and of LiF TLD-100 to low energy x-rays

Calculations of response to mono-energetic photons show that lithium borates containing 0, 0.1%, 0.25%, and 0.34% of Mn are equivalent to soft tissue (C₅H₄₀O₁₈N), water, ICRU muscle, and air respectively. Results obtained with monochromatic and broad-spectrum x-rays of effective energies between 12 and 115 kev are in agreement with this finding. The monochromatic and broad-spectrum x-ray beams were also used to explore the discrepancies in response of LiF TLD-100 to low energy photons. Only small discrepancies were found which were attributed either to breadth of x-ray spectra or to additional absorbed dose due to scattered x-rays amounting to 5% at 40 kev_eff.