Application of the Monte Carlo method to the analysis of doses and shielding around an X-ray fluorescence equipment

An X-ray fluorescence equipment is used for practical exercises in the laboratory. This equipment includes a compact X-ray tube, ECLIPSE-III, and a Si-PIN XR-100T detector. The voltage (30 kV), and the current (100 μA) of the tube are low enough so that expected doses around the tube do not represent a risk for the students working in the laboratory. Nevertheless, doses and shielding should be evaluated to accomplish the ALARA criterion. The Monte-Carlo method has been applied to evaluate the dose rate around the installation including a shield made of methacrylate plates 1 cm thick. Dose rates calculated are compared with experimental measurements to validate the model. The results show that doses are below allowable limits. Hence, no extra shielding is required for the X-ray beam. A previous Monte-Carlo model was also developed to obtain the tube spectrum and validated by comparison with data from manufacturer. (authors)