Radioactive contamination of SrI2(Eu) crystal scintillator

Abstract

A strontium iodide crystal doped by europium (SrI2(Eu)) was produced by using the Stockbarger growth technique. The crystal was subjected to a characterization that includes relative photoelectron output and energy resolution for γ quanta. The intrinsic radioactivity of the SrI2(Eu) crystal scintillator was tested both by using it as scintillator at sea level and by ultra-low background HPGe γ spectrometry deep underground. The response of the SrI2(Eu) detector to α particles (α/β ratio and pulse shape) was estimated by analysing the 226Ra internal trace contamination of the crystal. We have measured: α/β=0.55 at View the MathML source, and no difference in the time decay of the scintillation pulses induced by α particles and γ quanta. The application of the obtained results in the search for the double electron capture and electron capture with positron emission in 84Sr has been investigated at a level of sensitivity: View the MathML source. The results of these studies demonstrate the potentiality of this material for a variety of scintillation applications, including low-level counting experiments

Preliminary investigation of scintillator materials properties: SrI2:Eu, CeBr3 and GYGAG:Ce for gamma rays up to 9 MeV

“…Small samples (i.e. 1"x 1") of CeBr 3 and SrI 2 :Eu crystals appeared a few years later and there is still an intense R&D work on such detectors as the produced volume is constantly increasing over time [20][21][22][23][24][25][26][27][28][29]. The development of ceramic scintillator materials offers the possibility to have high-resolution gamma-ray spectroscopy at low cost.…”

“…SrI 2 :Eu has the best energy resolution (< 3%) among the studied detectors, and contains no internal radioactivity, but it is characterized by a slow signal and self-absorption [25][26][27][28][29]. The study of a large volume crystal is then important to understand how much the energy resolution is affected from this phenomenon.…”

“…Even though all three scintillator detectors studied in this work could be excellent substitutes of LaBr 3 :Ce, at the moment, only few detailed studies on large volume SrI 2 :Eu and CeBr 3 or in general on GYGAG:Ce scintillators [20][21][22][23][24][25][26][27][28][29][30][31][32][33][34] are available in literature. Table I.…”

Effects of Na and K co-doping on growth and scintillation properties of Eu:SrI2 crystals

“…Eu doped SrI 2 [Eu:SrI 2 ] scintillator crystal has high light yield (~80,000 ph/MeV) and high energy resolution (~3%) due to the small band-gap. Therefore, it is expected to be applied for next-generation radiation detector (Cherepy et al, 2008, Belli et al, 2012, Glodo et al, 2010, Cherepy et al, 2009, Hawrami et al, 2013, Gahane et al, 2009. The light yield proportionality of Eu:SrI 2 single crystal has been measured in the previous reports (Cherepy et al, 2008) and the Eu:SrI 2 single crystal indicated excellent light yield proportionality compared to the other scintillators as represented by Tl:NaI, Ce:LaBr 3 and Ce:Y 3 Al 5 O 12 .…”

Wide range automatic energy calibration of LaBr<inf>3</inf>:Ce detectors by the self-activity lines

“…For instant, the 176 Lu isotope (~2.6% abundance) in the Pr:Lu 3 Al 5 O 12 scintillator is a radioactive isotope emitting γ-rays whose energies are up to 400 keV [5]. Another example is the high resolution SrI 2 (Eu) detector which has many self-activity peaks arising from the impurities such as 40 K and 138 La and 176 Lu as γ-ray emitters, and 226 Ra and 228 Th as alpha emitters whose quenched energies are around 3 MeV [6]. In the present case, LaBr 3 (Ce) detector, there are two different types of self-activity.…”