Determination of optimal metallic secondary target thickness, collimation, and exposure parameters for X‐ray tube‐based polarized EDXRF

Abstract

Tube-based-polarized energy-dispersive X-ray fluorescence (EDXRF) is a powerful adaptation on traditional EDXRF, requiring very specific geometry and a scattering target to generate polarized X-rays. This secondary target is typically chosen to be a metallic foil, allowing for the polarization of the incident X-ray beam, and the addition of the secondary target's fluorescence response to the initial beam. A simulation, using GEANT4 Monte Carlo code, and an experimental confirmation were used to determine the optimal thickness of a metallic secondary target for use in tube-based-polarized EDXRF. The optimal thickness was determined by looking at the signal-to-noise ratio (SNR). Using the results, the optimal thickness and tube potential were calculated for the common secondary target materials Cu, Mo, and Sn, when looking at an Fe sample. The optimal thickness results were compared with the results when using an 'infinitely thick' target. The results show improvements in SNRs of 6 17%, illustrating the potential benefits of such calculations. Additionally, the optimal collimation of a polarized EDXRF system was examined, and it was found that increasing the total count rate should be the primary goal of geometrical optimization. If the count rate of the experimental setup is limited by tube output, then having the largest possible collimators yielded the maximum SNR. In contrast, if the count rate is limited by detector dead time, then decreasing the collimator size between secondary target and sample provided the maximal SNR.

Advances in the histopathological characterization of breast tissue using combined X‐ray fluorescence and X‐ray diffraction data in a multivariate analysis approach

“…Large differences can be seen in the K, Fe, and Zn peaks, with small apparent differences in the Ca and Cu peaks. The Ni and Ti peaks come from contaminants in the measuring system…”

“…The XRF measurements were taken using a PEDXRF system developed and optimized specifically for measuring soft biological tissues . PEDXRF systems allow for high fluence rate, multielemental analysis of samples .…”

“…The XRF measurements were taken using a PEDXRF system developed and optimized specifically for measuring soft biological tissues . PEDXRF systems allow for high fluence rate, multielemental analysis of samples . The newest generation of PEDXRF spectrometers allows for highly accurate results to be measured on benchtop systems in reasonable time frames, removing the need of a synchrotron radiation source to perform these XRF studies .…”

“…PEDXRF systems allow for high fluence rate, multielemental analysis of samples . The newest generation of PEDXRF spectrometers allows for highly accurate results to be measured on benchtop systems in reasonable time frames, removing the need of a synchrotron radiation source to perform these XRF studies . Similar to synchrotron sources, PEDXRF systems use a polarized X‐ray beam to excite the sample, reducing scatter incident on the detector, allowing for higher power sources to be utilized.…”

“…Similar to synchrotron sources, PEDXRF systems use a polarized X‐ray beam to excite the sample, reducing scatter incident on the detector, allowing for higher power sources to be utilized. The secondary target, which produces the polarized X‐ray source, can also be chosen to optimally excite elements of interest in the sample …”