scholarly journals Behaviour of Y203:Eu3+ Scintillator under Radiation used in Medical Applications

2019 ◽  
Vol 7 ◽  
pp. 233
Author(s):  
I. Kandarakis ◽  
D. Cavouras ◽  
G. S. Panayiotakis ◽  
D. Koutsogiorgis ◽  
D. Triantis ◽  
...  
Keyword(s):  
Medical Imaging ◽  
Conversion Efficiency ◽  
Light Emission ◽  
Radiation Detectors ◽  
Imaging Systems ◽  
Optical Parameters ◽  
X Ray ◽  
Luminescence Efficiency ◽  
Coating Weight ◽  
Light Conversion Efficiency

The Y2 O3:Eu3+ scintillator was studied for use in radiation detectors of medical imaging systems. Y2 O3 :Eu3+ was used in the form of laboratory prepared test screens. The x-ray luminescence efficiency of the screens was measured for tube voltages up 250 kVp. The intrinsic x-ray to light conversion efficiency (nc) and other optical parameters of the Y2 03:Eu3+ scintillator related to optical scattering, absorption, and reflection were determined. The light emission spectrum of Y2 03:Eu3+ was measured (λ=613 rim). The x-ray luminescence efficiency peaked at 180 mg/cm2 screen coating weight. The intrinsic x-ray to light conversion efficiency was found to be nc =0.095. Results indicated that Y2 03:Eu3+ is a medium to high overall performance material that could be used in medical imaging systems.

scholarly journals Research on Properties of X-Ray Detection Film Based on Thallium Doped Cesium Iodide

2021 ◽  
Vol 252 ◽  
pp. 02072
Author(s):  
Yang Yanbei ◽  
Tian Chunhui ◽  
Liu Shuang
Keyword(s):  
Film Thickness ◽  
Conversion Efficiency ◽  
Early Stage ◽  
Cesium Iodide ◽  
X Ray ◽  
The Monte Carlo Method ◽  
Wide Range ◽  
Imaging Performance ◽  
The Relationship ◽  
Light Conversion Efficiency

As X-ray detection imaging has a wide range of applications in medicine, industry, public safety, etc., it is of great significance to study its imaging mechanism and improve its imaging performance. Based on the process of X-ray luminescence in the scintillator material, this paper established a simulation model using a microcrystalline column structure to investigate the relationship between the thickness of the detection film and the light conversion efficiency. With the help of the simulation tool MATLAB, the Monte Carlo method was used to simulate the light conversion process of X-ray in the film, and the results were obtained as follows. Under the condition of other parameters unchanged, the luminous efficiency reached the peak value with the increase of the film thickness, and then gradually decreased with the increase of film thickness. The reason why the conversion efficiency in the early stage increases with the increase of the film thickness is that the film is in a saturated state, and increasing the thickness can cause more X-ray particles to be converted. As the film thickness increases, more fluorescent photons are absorbed as they propagate in the film, resulting in a gradual decrease in conversion efficiency. Therefore, an appropriate film thickness can be selected based on the simulation results to obtain the ideal light conversion efficiency.

Correcting organ motion artifacts in x-ray CT medical imaging systems by adaptive processing. I. Theory

2001 ◽  
Vol 28 (8) ◽  
pp. 1562-1576 ◽  
Author(s):  
A. C. Dhanantwari ◽  
S. Stergiopoulos ◽  
I. Iakovidis
Keyword(s):  
Medical Imaging ◽  
Motion Artifacts ◽  
Imaging Systems ◽  
Organ Motion ◽  
Adaptive Processing ◽  
X Ray

scholarly journals Optical Characteristics of ZnCuInS/ZnS (Core/Shell) Nanocrystal Flexible Films Under X-Ray Excitation

Crystals ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 343 ◽  
Author(s):  
George Saatsakis ◽  
Nektarios Kalyvas ◽  
Christos Michail ◽  
Konstantinos Ninos ◽  
Athanasios Bakas ◽  
...  
Keyword(s):  
Conversion Efficiency ◽  
Light Propagation ◽  
Photon Emission ◽  
Composite Films ◽  
Optical Characteristics ◽  
Core Shell ◽  
X Ray ◽  
Optical Photon ◽  
Flexible Films ◽  
Luminescence Efficiency

The aim of this article is to evaluate optical characteristics, such as the intrinsic conversion efficiency and the inherent light propagation efficiency of three polymethyl methacrylate (PMMA)/methyl methacrylate (MMA) composite ZnCuInS/ZnS (core/shell) nanocrystal flexible films. The concentrations of these were 100 mg/mL, 150 mg/mL, and 250 mg/mL, respectively. Composite films were prepared by homogeneously diluting dry powder quantum dot (QD) samples in toluene and subsequently mixing these with a PMMA/MMA polymer solution. The absolute luminescence efficiency (AE) of the films was measured using X-ray excitation. A theoretical model describing the optical photon propagation in scintillator materials was used to calculate the fraction of the generated optical photons passed through the different material layers. Finally, the intrinsic conversion efficiency was calculated by considering the QD quantum yield and the optical photon emission spectrum.

Luminescence Properties of $({\rm Lu},{\rm Y})_{2}{\rm SiO}_{5}:{\rm Ce}$ and ${\rm Gd}_{2}{\rm SiO}_{5}:{\rm Ce}$ Single Crystal Scintillators Under X-Ray Excitation for Use in Medical Imaging Systems

2007 ◽  
Vol 54 (1) ◽  
pp. 11-18 ◽  
Author(s):  
Ioannis G. Valais ◽  
Ioannis S. Kandarakis ◽  
Dimitris N. Nikolopoulos ◽  
Christos M. Michail ◽  
Stratos L. David ◽  
...  
Keyword(s):  
Medical Imaging ◽  
Single Crystal ◽  
Imaging Systems ◽  
Luminescence Properties ◽  
X Ray

scholarly journals Luminescence Efficiency of Cadmium Tungstate (CdWO4) Single Crystal for Medical Imaging Applications

Crystals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 429
Author(s):  
Christos Michail ◽  
Vaia Koukou ◽  
Niki Martini ◽  
George Saatsakis ◽  
Nektarios Kalyvas ◽  
...  
Keyword(s):  
Medical Imaging ◽  
Single Crystal ◽  
Optical Sensors ◽  
Light Output ◽  
High Energy ◽  
Published Data ◽  
X Rays ◽  
Cadmium Tungstate ◽  
X Ray ◽  
Luminescence Efficiency

Background: In this study, the light output of a cadmium tungstate (CdWO4) single crystal was measured under various X-ray radiographic energies. Methods: A CdWO4 single crystal (10 × 10 × 10 mm3) was exposed to X-rays in the 50–130 kVp range. Measurements were evaluated against published data for single crystals of equal dimensions (CaF2:Eu and Lu3Al5O12:Ce). Since the crystal was examined for application in medical imaging detectors, the emitted optical spectrum was classified with respect to the spectral compatibility of numerous commercial optical sensors. Results: The luminescence efficiency (LE) was found to constantly increase with X-ray energy and was higher than that of CaF2:Eu for energies above 90 kVp. However, the efficiency of the previously published Lu3Al5O12:Ce was found to be constantly higher than that of CdWO4. The light emitted from CdWO4 can be optimally detected by certain charge-coupled devices (CCDs), amorphous silicon photodiodes, and photocathodes. Conclusions: The high density (7.9 g/cm3) of CdWO4 and the luminescence signal of this material make it suitable for medical imaging (such as dual energy), high-energy physics or for applications of scintillators in harsh environments.

Evaluating scintillators used in radiation detectors of medical imaging systems by the effective fidelity index method

1999 ◽  
Vol 30 (1) ◽  
pp. 61-66 ◽  
Author(s):  
I. Kandarakis ◽  
D. Cavouras ◽  
P. Prassopoulos ◽  
E. Kanellopoulos ◽  
C.D. Nomicos ◽  
...  
Keyword(s):  
Medical Imaging ◽  
Radiation Detectors ◽  
Imaging Systems ◽  
Index Method
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