scholarly journals Quality Control and Structural Assessment of Anisotropic Scintillating Crystals

Crystals ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 376 ◽  
Author(s):  
Luigi Montalto ◽  
Pier Natali ◽  
Lorenzo Scalise ◽  
Nicola Paone ◽  
Fabrizio Davì ◽  
...  
Keyword(s):  
Residual Stress ◽  
High Energy Physics ◽  
Radiation Detectors ◽  
Structural Condition ◽  
High Energy ◽  
Complete Characterization ◽  
Non Invasive ◽  
Light Production ◽  
Core Elements ◽  
Stress States

Nowadays, radiation detectors based on scintillating crystals are used in many different fields of science like medicine, aerospace, high-energy physics, and security. The scintillating crystals are the core elements of these devices; by converting high-energy radiation into visible photons, they produce optical signals that can be detected and analyzed. Structural and surface conditions, defects, and residual stress states play a crucial role in their operating performance in terms of light production, transport, and extraction. Industrial production of such crystalline materials is a complex process that requires sensing, in-line and off-line, for material characterization and process control to properly tune the production parameters. Indeed, the scintillators’ quality must be accurately assessed during their manufacture in order to prevent malfunction and failures at each level of the chain, optimizing the production and utilization costs. This paper presents an overview of the techniques used, at various stages, across the crystal production process, to assess the quality and structural condition of anisotropic scintillating crystals. Different inspection techniques (XRD, SEM, EDX, and TEM) and the non-invasive photoelasticity-based methods for residual stress detection, such as laser conoscopy and sphenoscopy, are presented. The use of XRD, SEM, EDX, and TEM analytical methods offers detailed structural and morphological information. Conoscopy and sphenoscopy offer the advantages of fast and non-invasive measurement suitable for the inspection of the whole crystal quality. These techniques, based on different measurement methods and models, provide different information that can be cross-correlated to obtain a complete characterization of the scintillating crystals. Inspection methods will be analyzed and compared to the present state of the art.

scholarly journals Influence of a Surface Finishing Method on Light Collection Behaviour of PWO Scintillator Crystals

Photonics ◽  
2018 ◽  
Vol 5 (4) ◽  
pp. 47 ◽  
Author(s):  
Daniele Rinaldi ◽  
Luigi Montalto ◽  
Michel Lebeau ◽  
Paolo Mengucci
Keyword(s):  
High Energy Physics ◽  
Collection Efficiency ◽  
Removal Rate ◽  
Light Yield ◽  
Grazing Incidence ◽  
Structural Condition ◽  
High Energy ◽  
Production Performance ◽  
Surface Finishing ◽  
Light Collection

In the field of scintillators, high scintillation and light production performance require high-quality crystals. Although the composition and structure of crystals are fundamental in this direction, their ultimate optical performance is strongly dependent on the surface finishing treatment. This paper compares two surface finishing methods in terms of the final structural condition of the surface and the relative light yield performances. The first polishing method is the conventional “Mechanical Diamond Polishing” (MDP) technique. The second polishing technique is a method applied in the electronics industry which is envisaged for finishing the surface treatment of scintillator crystals. This method, named “Chemical Mechanical Polishing” (CMP), is efficient in terms of the cost and material removal rate and is expected to produce low perturbed surface layers, with a possible improvement of the internal reflectivity and, in turn, the light collection efficiency. The two methods have been applied to a lead tungstate PbWO4 (PWO) single crystal due to the wide diffusion of this material in high energy physics (CERN, PANDA project) and diagnostic medical applications. The light yield (LY) values of both the MDP and CMP treated crystals were measured by using the facilities at CERN while their surface structure was investigated by Scanning Electron Microscopy (SEM) and Grazing Incidence X-ray Diffraction (GID). We present here the corresponding optical results and their relationship with the processing conditions and subsurface structure.

scholarly journals Comparison of Neutron Detection Performance of Four Thin-Film Semiconductor Neutron Detectors Based on Geant4

Sensors ◽  
2021 ◽  
Vol 21 (23) ◽  
pp. 7930
Author(s):  
Zhongming Zhang ◽  
Michael D. Aspinall
Keyword(s):  
Thin Film ◽  
High Temperature ◽  
High Energy Physics ◽  
Detection Efficiency ◽  
Collection Efficiency ◽  
Radiation Detectors ◽  
High Energy ◽  
Semiconductor Materials ◽  
Third Generation ◽  
Neutron Detectors

Third-generation semiconductor materials have a wide band gap, high thermal conductivity, high chemical stability and strong radiation resistance. These materials have broad application prospects in optoelectronics, high-temperature and high-power equipment and radiation detectors. In this work, thin-film solid state neutron detectors made of four third-generation semiconductor materials are studied. Geant4 10.7 was used to analyze and optimize detectors. The optimal thicknesses required to achieve the highest detection efficiency for the four materials are studied. The optimized materials include diamond, silicon carbide (SiC), gallium oxide (Ga2O3) and gallium nitride (GaN), and the converter layer materials are boron carbide (B4C) and lithium fluoride (LiF) with a natural enrichment of boron and lithium. With optimal thickness, the primary knock-on atom (PKA) energy spectrum and displacements per atom (DPA) are studied to provide an indication of the radiation hardness of the four materials. The gamma rejection capabilities and electron collection efficiency (ECE) of these materials have also been studied. This work will contribute to manufacturing radiation-resistant, high-temperature-resistant and fast response neutron detectors. It will facilitate reactor monitoring, high-energy physics experiments and nuclear fusion research.

scholarly journals Using a Scintillation Detector to Detect Partial Discharges

Sensors ◽  
2019 ◽  
Vol 19 (22) ◽  
pp. 4936 ◽  
Author(s):  
Łukasz Nagi ◽  
Michał Kozioł ◽  
Michał Kunicki ◽  
Daria Wotzka
Keyword(s):  
Scintillation Detector ◽  
Power Plants ◽  
Early Stage ◽  
High Sensitivity ◽  
Radiation Energy ◽  
Radiation Detectors ◽  
High Energy ◽  
Partial Discharges ◽  
Non Invasive ◽  
Safety Regulations

This article presents the possibility of using a scintillation detector to detect partial discharges (PD) and presents the results of multi-variant studies of high-energy ionizing generated by PD in air. Based on the achieved results, it was stated that despite a high sensitivity of the applied detector, the accompanying electromagnetic radiation from the visible light, UV, and high-energy ionizing radiation can be recorded by both spectroscopes and a system commonly used to detect radiation. It is also important that the scintillation detector identifies a specific location where dangerous electrical discharges and where the E-M radiation energy that accompanies PD are generated. This provides a quick and non-invasive way to detect damage in insulation at an early stage when it is not visible from the outside. In places where different radiation detectors are often used due to safety regulations, such as power plants or nuclear laboratories, it is also possible to use a scintillation detector to identify that the recorded radiation comes from damaged insulation and is not the result of a failure.

Radiation hardness of PantherPix hybrid pixel detector

2021 ◽  
Vol 16 (12) ◽  
pp. P12007
Author(s):  
D. Dudas ◽  
V. Kafka ◽  
M. Marcisovsky ◽  
G. Neue ◽  
M. Marcisovska ◽  
...  
Keyword(s):  
High Energy Physics ◽  
Radiation Detectors ◽  
High Energy ◽  
Radiation Hardness ◽  
In Vivo Dosimetry ◽  
Detector Response ◽  
Semiconductor Detectors ◽  
Pixel Detector ◽  
Portal Dosimetry

Abstract Hybrid pixel detectors (HPD) are nowadays well known and widely used in fundamental research, e.g. in high energy physics experiments. Over the last decade, segmented semiconductor detectors have also found use in medicine. The total doses received by medical radiation detectors often reach a significant level (up to several hundreds of kGy per decade), especially in applications such as transmission portal in-vivo dosimetry. Such doses might affect detector properties. Therefore, it is necessary to evaluate their performance after absorbing a significant radiation dose. PantherPix is a novel 2D hybrid pixel detector which is designed specifically for use in radiation therapy. As was concluded in earlier studies, it is suitable for radiotherapy quality assurance (QA) and portal dosimetry. In this paper, the PantherPix radiation hardness is investigated using a 60Co source. The dependence on dose of the full depletion voltage, leakage current, detector power consumption and detector response are provided. The PantherPix radiation tolerance has been shown to be adequate for common cumulative doses delivered to radiation detectors in radiotherapy over several decades and its performance has been verified for doses up to 3000 kGy.

Designing high-resolution slow scan CCD-based TEM camera systems

1992 ◽  
Vol 50 (2) ◽  
pp. 946-947
Author(s):  
James F. Mancuso ◽  
William B. Maxwell ◽  
Russell E. Camp ◽  
Mark H. Ellisman
Keyword(s):  
Fiber Optics ◽  
Ccd Camera ◽  
High Energy ◽  
Phosphor Layer ◽  
X Ray ◽  
Light Production ◽  
Camera Systems ◽  
X Ray Imaging ◽  
Electron Image ◽  
Scintillating Fiber

The imaging requirements for 1000 line CCD camera systems include resolution, sensitivity, and field of view. In electronic camera systems these characteristics are determined primarily by the performance of the electro-optic interface. This component converts the electron image into a light image which is ultimately received by a camera sensor.Light production in the interface occurs when high energy electrons strike a phosphor or scintillator. Resolution is limited by electron scattering and absorption. For a constant resolution, more energy deposition occurs in denser phosphors (Figure 1). In this respect, high density x-ray phosphors such as Gd2O2S are better than ZnS based cathode ray tube phosphors. Scintillating fiber optics can be used instead of a discrete phosphor layer. The resolution of scintillating fiber optics that are used in x-ray imaging exceed 20 1p/mm and can be made very large. An example of a digital TEM image using a scintillating fiber optic plate is shown in Figure 2.

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