Assessments of the characteristics of an extrapolation chamber for 60 to 200 kVp X-rays: Experiment and Monte Carlo simulation

Abstract According to the principles of radiation protection, the patient and personnel dose should be decreased to a reasonably achievable level. Therefore, it is essential to use reliable dosimeters in the radiation dosimetry course. One of these dosimeters is an extrapolation chamber. It is a plane-parallel ion chamber (PPIC), which its sensitive volume can be varied. In this paper, the performance of an extrapolation chamber has been evaluated in 60–200 kVp X-rays. It was submitted to several necessary tests, and also simulated with MCNP code. All of the results were within the recommendations of the International Electrotechnical Commission (IEC). The chamber responses were linear with electrode separation. The comparison between experiment and simulation agrees in an overall sense within 5.4% in the worst case. The results indicated the usefulness of the chamber in this energy range. They show that the extrapolation chamber can also be used for computed tomography (CT) beams, considering that a primary standard system doesn't exist for these beams yet.