Spectra, ΓH*(10) and ΓKa produced by X-ray tubes, with Mo and Rh targets, in the diagnostic energy range

Vega-Carrillo H.R.; Campillo-Rivera G.E.; Vazquez-Bañuelos J.; Garcia-Reyna M.G.; Moreira-del Rio D.E.; Sanchez-Ortiz A.; Baltazar-Raigosa A.; Vasquez-Arteaga M. · Radiation Physics and Chemistry (2022) · DOI: 10.1016/j.radphyschem.2022.110300

Resumen

Voltage, current, target and filter in X-ray tubes define the X-ray spectrum; in turn, any dosimetric quantity depends on the spectrum. In the operation of an X-ray generator the dose is evaluated considering the contribution of leakage, scattered and direct beam contribution. For one X-ray unit using a voltage is important to know dose to 1 m per unit current (mA) and time (min); this feature is the Gamma factor (Γ). Using analog Monte Carlo methods, using the MCNP5 code, the objective of this work was to calculate the X-ray spectra and the Gamma factors for the ambient dose equivalent and air Kerma for X-units with two targets: Molybdenum and Rhodium and Aluminum filter. The X-rays are in the diagnostic energy range (70, 80, 90, 100, and 120 kV). Calculations were carried out in four positions (a, b, c and d) along the useful beam, and to account the radiation leakage calculations include two positions (L1 and L2) around the shielding. The spectra average energy and the Gamma factors for air Kerma and ambient dose equivalent were calculated. Low energy photons are eliminated by the glass enclosure and the filter. To 1 m from the focal spot (positions d, L1 and L2) the larger photon fluence and the Gamma factors for air Kerma and ambient dose equivalent are larger when the target in the tube is Rh in comparison to those having a target of Mo. In position d all Γ factors are described by a third degree polynomial.

Instituciones: Universidad Señor de Sipán