论文信息 - Design of field flattening filters for a high-power bremsstrahlung converter by full Monte Carlo simulation

Design of field flattening filters for a high-power bremsstrahlung converter by full Monte Carlo simulation

Abstract To compensate for off-axis dose reduction, biconical-shaped Pb field flattening filters were constructed for a specific high-power static TaC bremsstrahlung target configuration, at end-point energies 5 and 10 MeV. The filter design was optimized by full Monte Carlo simulation. The absolute dose calculation was compared to experimental ionization and Fricke measurements. Spectral data were analysed and the influence of incident electron beam parameters (diameter, oblique incidence) was simulated. With the constructed filtered set-up we are able to produce any required γ-dose rate up to a maximum value of 35 kGy/h in a water phantom at SSD 25 cm. The accomplished homogeneity at this distance is better than a few per cent over a surface of 25 cm diameter perpendicular to the beam axis, for both energies.

K. Van Laere | Willy Mondelaers | K. Laere | W. Mondelaers

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