The temperature dependence of the cavity ion chamber response was measured at room temperature in the range 17 • C to 27 • C. By analysing the variation of the ionization current with temperature produced in the cavity chamber, the temperature coefficient of the cavity chamber response was evaluated. The values were 4.1 × 10 −4 • C −1 , 4.3 × 10 −4 • C −1 and 2 × 10 −5 • C −1 for chambers made of C552 air equivalent plastic, polyoxymethylene and graphite, respectively.

The dosimetry parameters of the IRH10 (192)Ir high dose rate brachytherapy source were obtained from the dose calculation formalism recommended in the AAPM Task Group No. 43 report using the Monte Carlo code PENELOPE. The absorbed doses to water and air originating from the photons of the IRH10 (192)Ir brachytherapy source were calculated by the collision kerma approximation. The dose rate constant was evaluated to be (1.110 +/- 0.011) cGy/h U(-1). The dose rate per unit air kerma strength around the (192)Ir IRH10 brachytherapy source and the anisotropy function were given in tables and figures.

The X-ray spectra from a dual track mammography X-ray tube were calculated by means of Monte Carlo method using PENELOPE. The simulation geometry was modeled realistically. The variation of the calculated spectral shapes with the anode material, tube voltage and inherent filtration was investigated. Comparison of our results with other experimental and theoretical works was made. Detailed procedure of the simulation was described.

The response of a cylindrical NE2571 ionization chamber to the low-and medium-energy X-ray beams was simulated using a Monte Carlo code PENELOPE. The simulation geometry of the cylindrical chamber was modeled as specified by the manufacturer. The ratio of the air kerma to the cavity dose of the chamber was calculated as a function of photon energy for the broad parallel beam incident normally to the cylindrical axis of the chamber. Results were compared with other experimental and theoretical works

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