Design of photon energy compensation filters for the new four element CaSO4:Dy TLD badge

A new four element TLD badge using CaSO4:Dy is being developed for the estimation of personal dose equivalents Hp(10) and Hp(0.07) and to discriminate them in the mix field (low energy x-ray and high energy γ-ray). Design of energy compensation filters for the new TLD badge is discussed. The total metal filter thickness is kept less than 1 mm. The first and second elements of the badge are planned to be open and plastic (≅180 gm/cm2) window. For the third element a combination of 0.2 mm Sn + 0.7mm Cu + 0.1 mm Al with mass thickness ≅ 1100 mg/cm2 is proposed which gives energy dependent response similar to Hp(10) within ± 20% (above 80 keV). For the fourth dosimeter a filter combination of 0.4 mm Al + 0.07 mm Sn is proposed which gives Hp(10)xR response for diagnostic x-rays within ± 10% in the mix field. (author)