High Efficiency of Lutetium Silicate Scintillators, Ce-Doped LPS and LYSO Crystals for Medical Applications

2007 ◽  
Vol 555 ◽  
pp. 371-376 ◽  
Author(s):  
L. Pidol ◽  
Bruno Viana ◽  
Aurelie Bessière ◽  
A. Galtayries ◽  
P. Dorenbos ◽  
...  
Keyword(s):  
High Efficiency ◽  
Growth Parameters ◽  
Energy Levels ◽  
Light Yield ◽  
Fast Response ◽  
Good Energy Resolution ◽  
Scintillation Light ◽  
Time Resolved ◽  
Good Energy ◽  
Czochralski Process

The paper presents two cerium doped lutetium silicate crystals: pyrosilicate Ce:Lu2Si2O7 (LPS) and Ce: Lu2(1-x)Y2xSiO5 (LYSO). These two crystals exhibit the expected requirements for gamma detection: high density and high atomic number, high scintillation light yield, good energy resolution and fast response. LPS and LYSO crystals doped with cerium were grown by the Czochralski process. The crystal growth parameters were studied and optimized. Development of scintillators requires good understanding of the scintillation process. The location within the forbidden band gap of the localized lanthanide energy levels is analyzed by time resolved spectroscopy and thermoluminescence studies.

Comparison of Scintillation Light Yield of CWO and BGO Single Crystals for Gamma Ray Detection

2020 ◽  
Vol 901 ◽  
pp. 89-94
Author(s):  
Akapong Phunpueok ◽  
Voranuch Thongpool ◽  
Sarawut Jaiyen ◽  
Hua Shu Hsu
Keyword(s):  
Energy Resolution ◽  
Gamma Ray ◽  
Radiation Detection ◽  
Light Yield ◽  
Stopping Power ◽  
Good Energy Resolution ◽  
Scintillation Light ◽  
Radioactive Materials ◽  
Yield Value ◽  
Good Energy

Nowadays, radioactive materials are being applied in medical imaging. Because humans cannot observe radiation, radiation detection materials are very important to humans. A scintillator is a material that can change gamma photons to visible photons. Good scintillators should have the following properties: high scintillation light yield, good energy resolution, and high density. In this work, the scintillation light yield property of CWO crystals was studied due to its interesting properties, such as high stopping power and low hygroscopicity. CWO crystals were compared with BGO crystals. From the results, it was found that the BGO crystals showed higher scintillation light yield value at 662 keV energy from 137Cs radioactive source than the CWO crystals, resulting in better energy resolution value. The intrinsic light yield and loss parameters for both crystals are also presented in this work.

scholarly journals Inorganic, Organic, and Perovskite Halides with Nanotechnology for High–Light Yield X- and γ-ray Scintillators

Crystals ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 88 ◽  
Author(s):  
Francesco Maddalena ◽  
Liliana Tjahjana ◽  
Aozhen Xie ◽  
Arramel ◽  
Shuwen Zeng ◽  
...  
Keyword(s):  
High Energy Physics ◽  
Low Cost ◽  
Light Yield ◽  
Fast Response ◽  
High Energy ◽  
High Light ◽  
Scintillation Light ◽  
High Light Yield ◽  
Halide Perovskites ◽  
Lead Halide

Trends in scintillators that are used in many applications, such as medical imaging, security, oil-logging, high energy physics and non-destructive inspections are reviewed. First, we address traditional inorganic and organic scintillators with respect of limitation in the scintillation light yields and lifetimes. The combination of high–light yield and fast response can be found in Ce 3 + , Pr 3 + and Nd 3 + lanthanide-doped scintillators while the maximum light yield conversion of 100,000 photons/MeV can be found in Eu 3 + doped SrI 2 . However, the fabrication of those lanthanide-doped scintillators is inefficient and expensive as it requires high-temperature furnaces. A self-grown single crystal using solution processes is already introduced in perovskite photovoltaic technology and it can be the key for low-cost scintillators. A novel class of materials in scintillation includes lead halide perovskites. These materials were explored decades ago due to the large X-ray absorption cross section. However, lately lead halide perovskites have become a focus of interest due to recently reported very high photoluminescence quantum yield and light yield conversion at low temperatures. In principle, 150,000–300,000 photons/MeV light yields can be proportional to the small energy bandgap of these materials, which is below 2 eV. Finally, we discuss the extraction efficiency improvements through the fabrication of the nanostructure in scintillators, which can be implemented in perovskite materials. The recent technology involving quantum dots and nanocrystals may also improve light conversion in perovskite scintillators.

Comparative Studies of the Light Yield Non-Proportionality and Energy Resolution of CsI(Tl), LYSO and BGO Scintillation Crystals

2016 ◽  
Vol 872 ◽  
pp. 266-270
Author(s):  
Pruittipol Limkitjaroenporn ◽  
Narong Sangwaranatee ◽  
Wuttichai Chaiphaksa ◽  
Jakrapong Kaewkhao
Keyword(s):  
Energy Resolution ◽  
Comparative Studies ◽  
Gamma Ray ◽  
Light Yield ◽  
Good Energy Resolution ◽  
Intrinsic Resolution ◽  
Scintillation Crystals ◽  
Good Energy ◽  
Better Than

This article, for comparison, the non-proportionality of light yield and energy resolution of BGO, LYSO and CsI(Tl) scintillators couple to the R1306 PMT readouts were investigated. At 662 keV from 137Cs source, the good energy resolution of 7.13% for CsI(Tl) superior than LYSO and BGO scintillators. The energy resolution on gamma-ray energy was also evaluated to expose the scintillator intrinsic resolution parameters. For non-proportionality of light yield, the study showed a light yield non-proportionality 0.35% of LYSO, the value is better than 4.82 % for CsI(Tl) and 1.53 % of BGO scintillators.

The nuclear scattering of electrons and positrons at 0·7 and 1·4 MeV

1955 ◽  
Vol 229 (1177) ◽  
pp. 260-271 ◽  
Keyword(s):  
Incident Beam ◽  
Fast Response ◽  
Nuclear Scattering ◽  
Dirac Theory ◽  
Good Energy Resolution ◽  
Hollow Cone ◽  
Experimental Accuracy ◽  
Vertical Angle ◽  
Electrons And Positrons ◽  
Good Energy

An experiment is described in which electrons and positrons are scattered, under identical conditions, at energies of 0·7 and 1·4 MeV by foils of aluminium, silver and gold. Both the incident and scattered particles are counted by making use of the fast response and good energy resolution of anthracene crystals. The incident beam, which is in the form of a divergent hollow cone of semi-vertical angle of near 10°, and of 5% energy spread, is provided by using radioactive sources in a β-ray spectrometer. Effective angles of scattering of 22·8, 34·5 and 47·5° are employed. It is concluded that, within the experimental accuracy of about ±5% , the results are in accordance with predictions of the Dirac theory.

Scintillation Properties of Ce-Doped LuYAP Crystal for Gamma Ray Detection

2015 ◽  
Vol 804 ◽  
pp. 93-96
Author(s):  
Akapong Phunpueok ◽  
Voranuch Thongpool ◽  
Weerapong Chewpraditkul
Keyword(s):  
Energy Resolution ◽  
Gamma Ray ◽  
Light Yield ◽  
High Energy ◽  
Stopping Power ◽  
Strongly Correlated ◽  
Photon Yield ◽  
Good Energy Resolution ◽  
Intrinsic Resolution ◽  
Good Energy

In the present day, inorganic scintillating crystals become a main part in detection and spectroscopy of nuclear particles and high energy photons, more spectively in X/g-ray imaging. The good properties for the scintillating crystals used in these applications require high photon yield, high stopping power, good energy resolution, good light yield proportionality, and minimal afterglow. The main useful of Ce-doped Lu0.7Y0.3AlO3 (LuYAP(Ce)) are high stopping power and non-hygroscopic which are expected to be key ingredients for medical imaging. In this work, we studied the light yield non-proportionality and energy resolution of LuYAP(Ce) crystal with the energy range from 31 to 1,274.5 keV using photomultiplier tube (PMT) readout. The intrinsic resolution of the LuYAP(Ce) crystal has been determined after correcting the measured PMT resolution. The results showed that the non-proportional response of the crystals was strongly correlated with the intrinsic resolution of the crystals.

scholarly journals Electrochromic Performance and Capacitor Performance of α-MoO3 Nanorods Fabricated by a One-Step Procedure

Coatings ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 783
Author(s):  
Ying Duan ◽  
Chen Wang ◽  
Jian Hao ◽  
Yang Jiao ◽  
Yanchao Xu ◽  
...  
Keyword(s):  
Growth Parameters ◽  
Average Diameter ◽  
Fast Response ◽  
Cycle Stability ◽  
Electrochromic Devices ◽  
Step Procedure ◽  
One Step ◽  
Supercapacitor Performance ◽  
First Time ◽  
Prepared Nanorods

In this paper, we propose for the first time the synthesis of α-MoO3 nanorods in a one-step procedure at mild temperatures. By changing the growth parameters, the microstructure and controllable morphology of the resulting products can be customized. The average diameter of the as-prepared nanorods is about 200 nm. The electrochromic and capacitance properties of the synthesized products were studied. The results show that the electrochromic properties of α-MoO3 nanorods at 550 nm have 67% high transmission contrast, good cycle stability and fast response time. The MoO3 nanorods also exhibit a stable supercapacitor performance with 98.5% capacitance retention after 10,000 cycles. Although current density varies sequentially, the nanostructure always exhibits a stable capacitor to maintain 100%. These results indicate the as-prepared MoO3 nanorods may be good candidates for applications in electrochromic devices and supercapacitors.

scholarly journals Skyrmion Logic-In-Memory Architecture for Maximum/Minimum Search

Electronics ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 155
Author(s):  
Luca Gnoli ◽  
Fabrizio Riente ◽  
Marco Vacca ◽  
Massimo Ruo Roch ◽  
Mariagrazia Graziano
Keyword(s):  
High Efficiency ◽  
Digital Design ◽  
Control Logic ◽  
Minimum Number ◽  
Physical Simulations ◽  
Good Energy ◽  
Logic Functions ◽  
Time And Energy ◽  
Cmos Implementation ◽  
Maximum Minimum

In modern computing systems there is the need to utilize a large amount of data in maintaining high efficiency. Limited memory bandwidth, coupled with the performance gap between memory and logic, impacts heavily on algorithms performance, increasing the overall time and energy required for computation. A possible approach to overcome such limitations is Logic-In-Memory (LIM). In this paper, we propose a LIM architecture based on a non-volatile skyrmion-based recetrack memory. The architecture can be used as a memory or can perform advanced logic functions on the stored data, for example searching for the maximum/minimum number. The circuit has been designed and validated using physical simulations for the memory array together with digital design tools for the control logic. The results highlight the small area of the proposed architecture and its good energy efficiency compared with a reference CMOS implementation.

scholarly journals Modified Levy Flight Optimization for a Maximum Power Point Tracking Algorithm under Partial Shading

2021 ◽  
Vol 11 (3) ◽  
pp. 992
Author(s):  
Chanuri Charin ◽  
Dahaman Ishak ◽  
Muhammad Ammirrul Atiqi Mohd Zainuri ◽  
Baharuddin Ismail
Keyword(s):  
High Efficiency ◽  
Energy System ◽  
Fast Response ◽  
Lévy Flight ◽  
Partial Shading ◽  
Levy Flight ◽  
Point Tracking ◽  
Power Point Tracking ◽  
Steady State Oscillation ◽  
Power Point

This paper presents a novel modified Levy flight optimization for a photovoltaic PV solar energy system. Conventionally, the Perturb and Observe (P&O) algorithm has been widely deployed in most applications due to its simplicity and ease of implementation. However, P&O suffers from steady-state oscillation and stability, besides its failure in tracking the optimum power under partial shading conditions and fast irradiance changes. Therefore, a modified Levy flight optimization is proposed by incorporating a global search of beta parameters, which can significantly improve the tracking capability in local and global searches compared to the conventional methods. The proposed modified Levy flight optimization is verified with simulations and experiments under uniform, non-uniform, and dynamic conditions. All results prove the advantages of the proposed modified Levy flight optimization in extracting the optimal power with a fast response and high efficiency from the PV arrays.

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