Dose distributions of X-rays in water: measurement with TL-dosimeters and comparison with Monte-Carlo calculations.

The dose distribution of x-rays in a water phantom was investigated with LiF (TLD-100) TL-dosimeters. The dose distribution was measured on the central axis and perpendicular to it at different depths. The x-ray tube voltage, field area, source to skin distance (SSD) and phantom thickness were varied between measurements. The experimental results were compared with Monte-Carlo calculations. Theoretical x-ray spectra were used in these calculations. The measured and calculated values agree well with each other; differences in doses were generally less than 10%. The variations in measured dose distributions due to variations in field area, SSD and phantom thickness agree well with the calculated values.