The hard X-ray response of Ce-doped lanthanum halide scintillators

✍ Scribed by Alan Owens; A.J.J. Bos; S. Brandenburg; P. Dorenbos; W. Drozdowski; R.W. Ostendorf; F. Quarati; A. Webb; E. Welter

• Publisher: Elsevier Science
• Year: 2007
• Tongue: English
• Weight: 330 KB
• Volume: 574
• Category: Article
• ISSN: 0168-9002
• DOI: 10.1016/j.nima.2007.01.092

✦ Synopsis

We summarize the results of a number of hard X-ray measurements on cerium-doped LaCl 3 and LaBr 3 scintillators. The experiment was carried out at the HASYLAB synchrotron radiation facility using highly monochromatic pencil beams across the energy range 10.5-100 keV. Additional full-area measurements were carried out using radioactive sources. All measurements were carried out at room temperature. The measured FWHM energy resolutions (DE/E) under pencil beam illumination were 29% (LaBr 3 ) and 32.4% (LaCl 3 ) at 10.5 keV falling to 7.8% (LaBr 3 ) and 9.2% (LaCl 3 ) at 100 keV. At 662 keV, the energy resolutions were 3.9% and 3.0% FWHM. The proportionality of the energy responses shows marked deviations from linearity above and below the La edge at 39.8 keV. At the edge the energy response changes by 3%. Fine structure across the edge was also investigated using single photon count rate measurements taken in 1 eV steps across the edge. The data show considerable near-edge structure when compared to curves generated from standard atomic data tables. However, very little evidence was found for extended X-ray fine structure suggesting that the bulk of the structure arises from the local coordination environment.