안티몬 차폐시트의 감마선 차폐 성능평가

Performance Evaluation of Gamma ray Shielding of Antimony Shielding Sheet

In this study, the dose of antimony shielding sheet was measured and the shielding rates according to the dis-tance between the radioisotopes and the detector was analyzed according to the type of 99m Tc, 18 F, 201 Tl, 131 I, 123 I using the antimony shielding sheet. The detector was used with an inspector. Six sheets of 0.25 ㎜Pb were prepared with 20 ㎝ width and length. Measurement results using 99m Tc, 201 Tl, and 123 I showed that as the thickness of the sheet became thicker, the farther the distance from the source to the sheet was, the smaller the transmitted dose amount was measured. It was analyzed that a thickness of 1.50㎜ or more was required to obtain a shielding rates of 90% or more. In the experiments of 18 F and 131 I, the dose value was highest when 0.25 ㎜ sheet was used, and the shielding rates was negative, unlike the results of other radioisotopes. Since 201 Tl are used when using antimony sheet and 18 F and 131 I have no shielding effect, it is thought that it is effective to reduce dose by repeating training and simulation training so that work can be done in a short time.