title: Linear fitting of multi-threshold counting data with a pixel-array detector for spectral X-ray imaging.
abstract: Experiments and modeling are described to perform spectral fitting of multi-threshold counting measurements on a pixel-array detector. An analytical model was developed for describing the probability density function of detected voltage in X-ray photon-counting arrays, utilizing fractional photon counting to account for edge/corner effects from voltage plumes that spread across multiple pixels. Each pixel was mathematically calibrated by fitting the detected voltage distributions to the model at both 13.5 keV and 15.0 keV X-ray energies. The model and established pixel responses were then exploited to statistically recover images of X-ray intensity as a function of X-ray energy in a simulated multi-wavelength and multi-counting threshold experiment.
authors.affiliation: Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, IN 47907, USA.
authors.forename: Ryan D
authors.initials: RD
authors.lastname: Muir
authors.affiliation: Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, IN 47907, USA.
authors.forename: Nicholas R
authors.initials: NR
authors.lastname: Pogranichney
authors.affiliation: IMCA-CAT, Hauptman-Woodward Medical Research Institute, Argonne National Laboratory, Argonne, IL 60439, USA.
authors.forename: J Lewis
authors.initials: JL
authors.lastname: Muir
authors.affiliation: Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, IN 47907, USA.
authors.forename: Shane Z
authors.initials: SZ
authors.lastname: Sullivan
authors.affiliation: IMCA-CAT, Hauptman-Woodward Medical Research Institute, Argonne National Laboratory, Argonne, IL 60439, USA.
authors.forename: Kevin P
authors.initials: KP
authors.lastname: Battaile
authors.affiliation: IMCA-CAT, Hauptman-Woodward Medical Research Institute, Argonne National Laboratory, Argonne, IL 60439, USA.
authors.forename: Anne M
authors.initials: AM
authors.lastname: Mulichak
authors.affiliation: Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, IN 47907, USA.
authors.forename: Scott J
authors.initials: SJ
authors.lastname: Toth
authors.affiliation: IMCA-CAT, Hauptman-Woodward Medical Research Institute, Argonne National Laboratory, Argonne, IL 60439, USA.
authors.forename: Lisa J
authors.initials: LJ
authors.lastname: Keefe
authors.affiliation: Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, IN 47907, USA.
authors.forename: Garth J
authors.initials: GJ
authors.lastname: Simpson
mesh_terms: D002138:Calibration; D007089:Image Enhancement / Q000295:instrumentation / Q000379:methods; D008433:Mathematics; D017785:Photons; D011874:Radiometry / Q000295:instrumentation*; D012542:Scattering, Radiation; D014056:Tomography, X-Ray / Q000379:methods*
keywords: energy dispersive; fractional counting; multi-wavelength; spectroscopic imaging