Off‐axis x‐ray spectra: A comparison of Monte Carlo simulated and computed x‐ray spectra with measured spectra

Abstract

The off-axis x-ray spectra from a constant potential x-ray generator were measured with a high purity germanium spectrometer cooled to liquid nitrogen temperature. The measured spectra were compared with off-axis x-ray spectra calculated using a code based on the semiempirical model developed by Tucker et al. and Monte Carlo simulated x-ray spectra using the EGS4 code system. In this study, both the Tucker model, and the EGS4 code system, were found to produce off-axis bremsstrahlung x-ray spectra which agreed well with the spectra measured at three emerging angles. In the measured and the EGS4 generated spectra the total K-characteristic peaks were in increasing order, as observed in the anode to cathode direction, whereas the Tucker model produced maximum total K-characteristic peaks at the 6 degrees anode side, and lesser amounts at the central axis and the 6 degrees cathode side. Large differences in the total K-characteristic lines is seen among the three different methods. The EGS4 code system was able to produce x-ray spectra for a combination of target materials.

Modification of the TASMIP x-ray spectral model for the simulation of microfocus x-ray sources

“…Sisniega, Desco, and Vaquero: Modification of the TASMIP model for microfocus sources 011902-9 19 These values are in line with the mean error of 3.3% for aluminum thicknesses up to 4 mm shown by our modified TASMIP model and with a mean error of 11.7% when using copper with a maximum thickness of 0.3 mm. While in our validation study the maximum thickness of aluminum is lower than in the study by Ay, 32 the maximum attenuation factor is similar (∼0.05), allowing us to compare our results with those in Ref.…”

Monte Carlo simulation of x-ray spectra generated by kilo-electron-volt electrons

“…2,3 Although, in principle, x-ray spectra can be computed from the numerical solution of the electron-transport equation, 4 Monte Carlo ͑MC͒ simulation has proven to be the most suitable method for the calculation of electroninduced x-ray spectra, mostly because it can incorporate realistic interaction cross sections and can be applied to targets with complex geometries.…”

X-ray imaging using K-edge filters

“…Very good agreement is shown in the 20 -69 keV energy range. The flux drop of the measured spectra over 69 keV is attributed to the so called heel effect, which was simulated by Monte Carlo method and also measured by Bhat et al [12]. This effect refers to a fall off of intensity in the X-ray radiation when the electron beam from the cathode hits the anode at a small angle.…”