The characterization of Eu super(2+)-doped mixed alkaline-earth iodide scintillator crystals

• Published in: Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment Vol. 643; no. 1; pp. 75 - 78
• Main Authors: Neal, John S, Boatner, Lynn A, Ramey, Joanne O, Wisniewski, Dariusz, Kolopus, James A, Cherepy, Nerine J, Payne, Stephen A
• Format: Journal Article
• Language: English
• Published: 01-07-2011
• Subjects: Columnar structure; Crystals; Detectors; Europium; Iodides; Magnesium; Spectrometers; Strontium
• ISSN: 0168-9002
• DOI: 10.1016/j.nima.2011.04.010

The high-performance inorganic scintillator, SrI sub(2):Eu super(2+), when activated with divalent europium in the concentration range of 3-6%, has shown great promise for use in applications that require high-energy-resolution gamma-ray detection. We have recently grown and tested crystals in which other alkaline-earth ions have been partially substituted for strontium ions. Specifically, europium-doped single crystals have been grown in which up to 30 at% of the strontium ions have been substituted for by barium, magnesium, or calcium ions. In the case of the strontium iodide scintillator host, a material that is characterized by an orthorhombic crystal structure, three other column IIA elements are obvious choices for investigations intended to realize potential improvements in the performance of SrI sub(2):Eu super(2+)-based scintillators via the replacement of strontium ions with Mg super(2+), Ca super(2+), or Ba super(2+). Light yields up to 81,400 photons/MeV with an associated energy resolution of 3.7% (fwhm for 662 keV gamma rays) have been observed in the case of partial substitution of Ba super(2+) for Sr super(2+). The measured decay times ranged from 1.1 to 2.0 mu s, while the peak emission wavelengths ranged from 432 to 438 nm.