Conveners
Characterization: session 2
- Pieter Dorenbos (TU Delft)
Characterization: session 2
- William Moses (LBNL)
While SrI2(Eu)’s excellent scintillation performance and CLYC(Ce)’s dual mode detection capability make these halides ideal candidates for nuclear radiation detection, these materials are expensive due to decreased crystal growth yield at large diameters (e.g. 3 inches). However, the cost of encapsulating small diameter crystals into a large plastic matrix such as polyvinyltoluene...
Last studies [1-3] demonstrated high efficiency of UV luminescence of undoped yttrium aluminum garnet (YAG). Radio-luminescence of pure crystals most probably related to excitons localized around defects, due to violation of the stoichiometric composition. At the same time there are different types of defects presence in the lattice. Pure YAG crystals emit a broad UV emission band under...
Recently, Ce:(La, Gd)$_2$Si$_2$O$_7$ (Ce:La-GPS) scintillator was reported the have a good energy resolution (FWHM) of ~5% at 662 keV, and its light output remained constant up to 150 $^{\circ}$C (423K) [1,2]. Moreover, we grew larger size Ce:La-GPS crystals by Czochralski process up to 2 inch diameter and studied their scintillation properties. Up to now, we have shown the scintillation...
A family of lithium silicate glasses and glass ceramics doped with Ce ions show high light yield under thermal neutrons [1]. There are several lithium containing scintillation glasses available on the market. The most widely applied scintillation glass is GS-20 type glass, which has a complex Si-Al-Li-Mg-Ce composition. This composition is hardly used to obtain glass ceramics, which has...
The development of new crystalline materials for ionizing radiation detectors is still playing a significant role in applications in high energy physics (HEP). Further concepts of the detectors at HEP experiments will require an unique combination of the material features, particularly in case of collider experiments. A possible candidate can be the so called DSB: Ce glass ceramics obtained...
In recent years, the sol-gel technique was proven to allow a good control, at a relatively low densification temperature, of rare earth (RE) ions incorporation and of their dispersion inside the glass matrix [1]. The glass synthesis can be performed by using high purity precursors, reducing the level of unwanted impurities, which is an essential feature for the radiation hardness of such...
The emergence of new solid-state avalanche photodetectors, e.g. SiPMs, with unprecedented timing capabilities opens new ways to profit from ultrafast and prompt photonemission in scintillators. In time of flight positron emission tomography (TOF-PET) and high energy timing detectors based on scintillators the ultimate coincidence time resolution (CTR) achievable is proportional to the square...
Recently, we showed that the codoping of GAGG:Ce single crystal by Mg results in a strong acceleration of the rate of free carriers nonradiative recombination. This effect competes with the radiative recombination of free carriers via Ce3+ ions and, consequently, results in a decrease of the scintillator light yield. The nonradiative recombination occurs when a hole migrates to the vicinity...
The Mg co-doping in Ce-activated garnet scintillators has shown several highly beneficial effects, such as acceleration of the scintillation decay or improved afterglow, while the LY remains sufficiently high [1]. Excellent scintillation properties have recently been reported in garnet epitaxial films GAGG:Ce,Mg grown by liquid phase epitaxy [2].
In this work, the effect of Mg2+ co-doping on...
Scintillators based on lutetium-aluminum garnet LuAG:Ce have been studied in past decades. Besides many favorable properties, slow decay components related to retrapping of electrons on the shallow traps related to anti-site defects in caused deterioration of scintillation parameters. These defects, where Lu resides at Al sites, are created at high temperatures during crystal growth from the...
Point defects play a relevant role in the scintillation process since they can act as traps for free carriers, created by the interaction of ionizing radiation with the scintillator, slowing down the carriers migration toward the radiative recombination centres. The competition which arises between charge trapping and recombination is ultimately responsible for the degradation of the...
In this study we used a waveform digitizer to record, store and analyse individual scintillation pulses from the following scintillators: CeBr3, LaB3:Ce, LaBr3:Ce,Sr, NaI:Tl, CsI:Tl, and BaF2. With off-line analysis software we sorted the pulses according to their charge integrals. Then we obtained the pulse shape as a function of energy deposited within a scintillator. The result on pulse...
