A new inorganic scintillation material based on Ba-Gd silica glass doped with cerium (BGS) is fabricated and studied. With the highest light yield among heavy glasses at the level of 2500 ph/MeV and ...fast scintillation response, the new scintillator ensures a good coincidence time resolution of < 230 ps FWHM for 511 keV γ-quanta from a 22Na source and SiPM readout. In addition to good performance in γ-quanta detection, the material demonstrates capability for efficient detection of low-energetic neutrons. The scintillator is produced by exploiting the standard industrial glass technology, which allows for an unlimited scaling up the conversion of raw material into a high-quality scintillator at a high rate. The glass can be casted in application-specific molds, so minimizing the material losses. The presented glass scintillator has potential for further improvement of its light output and scintillation response time.
Several scintillation CaMoO 4 crystals with size up to 28times28times220 mm 3 were grown by the Czochralski method. Their scintillation properties have been evaluated. Light yield of full size ...crystals measured with a XP2020 PMT is about 4% relative to a small reference CsI(Tl) crystal. Radio luminescence spectrum under gamma-excitation contains single emission peak with maximum at 520 nm. Optical transmission spectra contain a weak absorption band around 420 nm, which has almost no influence on scintillation light. This allows to produce even larger scintillation elements without deteriorating the light yield. Scintillation kinetics was measured under gamma- and alpha-particle excitation both in fast (2000 ns) and slow (200 mus) time scales. Fast components - 12 ns, (0.1%); 200 ns (0.5%) were detected along with slow - 3.8 mus (3.4%); 20 mus (96%) - components. Difference in fast component contribution under gamma and alpha excitation allows to implement pulse-shape discrimination of alpha-radioactive background coming from impurities in the crystals.
Composition-property correlations have been systematically studied in the full concentration range of Y
3
Al
5−
x
Ga
x
O
12
:Ce (YAGG:Ce) scintillator crystals. The most promising compositions for ...new high energy physics experiments at colliders have been determined with the light output >200% relative to BGO and fast luminescence decay. Codoping with Ca
2+
provides the decrease of phosphorescence intensity to 0.2% after 0.6 μs and shortening of the luminescence decay constant to 21 ns. Factors affecting the scintillation decay time in YAGG:Ce have been discussed. The crystals show weak transmission loss under γ-irradiation. The feasibility to produce YAGG:Ce fibers using the μ-PD method has been shown.
Fast and bright Y
3
Al
5−
x
Ga
x
O
12
:Ce,Ca garnet scintillation crystals were developed for high energy physics detectors.
The development of lead tungstate scintillator with the scintillation decay decreased down to the subnanosecond domain is reported. The material exhibits a scintillation decay with a time constant of ...640 ps at a light yield of 7 phe/MeV and a high radiation tolerance to the electromagnetic component of ionizing radiation. It is shown to be an outstanding candidate for dual readout of scintillation and Cherenkov photons in electromagnetic calorimetry at future collider experiments.
Abstract
We studied the light yield of a pure polystyrene slide
coated with wavelength-shifter molecules, coupled to a
photomultiplier, using
β
-
particles from a
90
Sr
source, as a possible ...easy-to-build, low-cost plastic scintillator
detector. Comparison measurements were performed with an uncoated
polystyrene slide as well as with uncoated and coated PMMA slides,
the latter which can only produce Cherenkov light when being
traversed by charged particles. The results with the single (double)
coated polystyrene slides show about 4.9 (6.3) times higher detected
photon yield compared to the uncoated slide. For comparison, the
light yield of a polystyrene-based extruded plastic scintillator
material doped with PTP and POPOP was measured as well. The
absolute detected light yield motivates future studies for
developing easy-to-build, low-cost polystyrene-based plastic
scintillator detectors.
High light yield scintillation materials on the base of lanthanide ions were demonstrated to be a multipurpose scintillation materials. They are widely used to detect γ–quanta and now become ...prospective to detect neutrons as well. Neutrons were detected through several distinct low energy γ–quanta peaks, generated by lanthanide nuclei in the materials under neutrons. Among three crystalline scintillators, namely lutetium oxy-orthosilicate, lanthanum bromide and gadolinium–aluminum–gallium garnet, the Gd3Al2Ga3O12:Ce (GAGG) scintillator showed the best performance and sensitivity due to the low internal background radioactivity and good cross section of neutron capture by natural mixture of the matrix host-creating Gd ions. The material fits the requirements for neutron detector properties — high Gd content and high scintillation light yield, stopping power and reasonable energy resolution for γ-quanta. These findings create prospects to construct compact multipurpose detectors for space and other application.
The lead tungstate crystal (PbWO 4 , PWO) is one of the widely used scintillation materials for electromagnetic calorimeters (EMCs) in high-energy physics experiments. The degradation of the optical ...transmittance in the range of the luminescence spectrum under ionizing radiation leads to losses of the light output resulting in the deterioration of the energy resolution and limiting the lifetime of the calorimeter. A possible way to restore radiation damage is the in situ illumination by visible or near-infrared light of the whole crystal volume. It allows recovering the transmittance losses due to the depopulation of the color centers. Such a kind of stimulated recovery subsystem based on a blue light-emitting diode is considered for the EMC of the PANDA detector at Facility for Antiproton and Ion Research (FAIR) (Darmstadt, Germany). Here, we report on the stimulated recovery studies of the lead tungstate radiation damage induced by external light from laser diodes at different wavelengths. The level of technological development of laser diodes allows increasing the efficiency of the stimulated recovery.
Ceramic samples of (Gd,Y)3(Ga,Al)5O12:Ce compounds were obtained by air sintering of uniaxially pressed powders, synthesized using a coprecipitation approach. The resulting material contained several ...percent of pores and was light scattering but translucent, with estimated light yield of 4.5 ph/keV under γ-ray excitation. The ceramic samples demonstrated the ability to detect neutrons from an Am–Be source – more than 70% of the signal was estimated to be caused by neutrons of energies exceeding 1 eV.
•Translucent Gd-loaded garnet ceramic samples were obtained by air sintering.•Estimated light yield was 4.5 ph/keV under γ-ray excitation.•Neutron signal from an Am–Be source was detected.•More than 70% of the signal was assigned to neutrons with energies exceeding 1 eV.
The application of crystalline materials in ionizing radiation detectors has played a crucial role in the discovery of the properties of matter. However, the experiences gathered at high intensity ...machines such as the LHC have indicated their limitations and underlined the requirements for materials being more tolerable to radiation damage in particular caused by energetic hadrons. Systematic studies of the radiation hardness of inorganic optical and scintillation materials propose both oxide and fluoride crystals composed of atoms with atomic numbers below 60. In this study we report on a cheap glass (BaO*2SiO2) and DSB: Ce glass ceramics even capable for mass production. Admixing gadolinium oxide (Gd3+) even provides a two times larger light yield. Both types of the materials can be produced in a fibre and bulk geometry. This paper summarizes the overall performance and reports on a first test of a 3x3 matrix of large volume samples exposed to energy-marked photons up to 180 MeV.
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