This report presents results on the optical transmission damage of undoped and Ce doped Y3Al5O12 scintillation crystals under high fluence of 24GeV protons. We observed that, similarly to other ...middle heavy scintillators, it possesses the unique radiation hardness at fluence values as high as 5×1014p/cm2 and it is thus promising for the application in the detectors at High Luminosity LHC. The crystalline structure of the garnet scintillator allows to control and further optimize its scintillation parameters, such as scintillation decay time and emission wavelength, and shows a limited set of the radioisotopes after the irradiation with protons.
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.
This report presents results on the significant improvement of GAGG:Ce based scintillation detector performance with temperature decrease. When temperature of a PMT based detector is lowered to ...−45 °C, its amplitude response at registration of γ-quanta is improved by 30%; FHHM was found to be better up to factor of 0.85, whereas scintillation kinetics become even faster in crystals co-doped with magnesium and magnesium and titanium. All this opens an opportunity for a wide application of GAGG scintillation detectors, particularly in a combination with SiPM photo-sensors, which signal-to-noise ratio would also improve with temperature decrease.
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.
The response of two generations of prototypes of the P¯ANDA Electromagnetic Calorimeter (EMC), PROTO60 and PROT120, to photons in the energy range between 50MeV and 800MeV was obtained. Furthermore, ...the performance of the pre-amplifier ASIC (APFEL) under real experimental conditions, the position dependence of the energy resolution within the crystal and the implementation of higher order energy correction algorithms with a 15GeV/c positron beam were studied.
The response of two generations of prototypes of the View the MathML sourceP¯ANDA Electromagnetic Calorimeter (EMC), PROTO60 and PROT120, to photons in the energy range between 50 MeV and 800 MeV was ...obtained. Furthermore, the performance of the pre-amplifier ASIC (APFEL) under real experimental conditions, the position dependence of the energy resolution within the crystal and the implementation of higher order energy correction algorithms with a 15 GeV/c positron beam were studied.
Recently, a new scintillation material DSB: Ce super(3+) was announced. It can be produced in a form of glass or nano-structured glass ceramics with application of standard glass production ...technology with successive thermal annealing. When doped with Ce super(3+), material can be applied as scintillator. Light yield of scintillation is near 100 phe/MeV. Un-doped material has a wide optical window from 4.5eV and can be applied to detect Cherenkov light. Temperature dependence of the light yield LY(T) is 0.05% which is 40 times less than in case of PWO. It can be used for detectors tolerant to a temperature variation between -20degrees to +20degreesC. Several samples with dimensions of 15x15x7 mm super(3) have been tested for damage effects on the optical transmission under irradiation with gamma -quanta. It was found that the induced absorption in the scintillation range depends on the doping concentration and varies in range of 0.5-7 m super(-1). Spontaneous recovery of induced absorption has fast initial component. Up to 25% of the damaged transmission is recuperated in 6 hours. Afterwards it remains practically constant if the samples are kept in the dark. However, induced absorption is reduced by a factor of 2 by annealing at 50degreesC and completely removed in a short time when annealing at 100degreesC. A significant acceleration of the induced absorption recovery is observed by illumination with visible and IR light. This effect is observed for the first time in a Ce-doped scintillation material. It indicates, that radiation induced absorption in DSB: Ce scintillation material can be retained at the acceptable level by stimulation with light in a strong irradiation environment of collider experiments.
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