Determination of Mean Energy and Energy Resolution of Standardized Diagnostic X-ray Beams from the Spectra Measured...

The objective of this work was to measure the spectra of standardized diagnostic X-ray beams (DXRBs) using a cadmium zinc telluride (CdZnTe) spectrometer. The mean energy as well as energy resolution were also estimated from the measured spectra.

The CdZnTe radiation detector of nominal volume 500 mm³ in combination with an in-house-developed tungsten pinhole collimator was used to measure the spectra of standardized DXRBs of nominal energies 40 kV to 100 kV. The detector was placed at a distance of 1000 mm from the focal spot of the X-ray tube, and the field size of 200 mm × 200 mm was opened. The ²⁴¹Am, ¹³³Ba, and ⁵⁷Co reference gamma ray sources were used for the calibration of the CdZnTe spectrometer. The measured spectra were corrected using the stripping procedure and the methodology was validated by comparing the corrected and reference spectra. The mean energy values and energy resolution were determined from the corrected spectra. The effective energies of beams were also determined from the first half-value layer measured experimentally.

The mean energies estimated from corrected X-ray spectra agreed within 5% for the beam qualities studied. The energy resolution deteriorated with the energy of DXRBs.

In-house-developed pinhole collimator, and CdZnTe spectrometer were successfully used for the measurement of DXRBs spectra. The X-ray beams have been fully characterized for the calibration of diagnostic X-ray dosimeters and quality control instruments.