The angular dependence of thermoluminescence dosimeters used in computational tomographs

The thermoluminescent dosimetry has been used widely to quantify the radiation doses in diagnoses radiology and radiotherapy. The LiF (TLD 100) dosimeters are generally used. An error source is being introduced by the differences in the irradiation geometry observed between the calibration and the measure in tomography devices. The code Monte Carlo MCNP4B is used in this work to simulate the direction change effects, varying the incident angle between 0 to 90 for X-ray spectrum from 120 to 140 kVp, in air, water and acrylic