Determination of percentage depth dose for 6 and 10 MV x-rays using Ge-doped optical fibre and TLD-100

摘要

Percentage depth doses for 6 and 10 MV x-ray beams from a linear accelerator were measured using ～1 cm long (～0.3 mg) Ge-doped optical fibre as a thermoluminescence dosimeter for two field sizes, 5 * 5 and 10 * 10 cm~2. The results indicate that the Ge-doped optical fibre dosimeter is in good agreement with the results from a PTW 30001 cylindrical ionisation chamber and TLD-100. For 6 MV x-ray beams we observe that the depth of maximum dose d_(max) is 1.5 and 2 cm for field sizes of 5 * 5 and 10 * 10 cm~2 respectively. For 10 MV d_(max) is 2 cm for a field size of 5 * 5 cm~2 and 2.5 cm for a 10 * 10 cm~2 field.