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1

Detection system for a miniature MEMS X-ray source

Urbański Paweł, Grzebyk Tomasz

Opto-Electronics Review

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2023

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Vol. 31, No. 4

art. no. e147038

EN

The article presents the results of experiments on a detection system used for detecting signals from a miniature, low-energy micro-electro-mechanical system (MEMS) X-ray source. The authors propose to use a detection based on luminescence phenomena occurring in luminophore and scintillators to record the visual signal on a CMOS/CCD detector. The main part of the article is a review of various materials of scintillators and luminophores which would be adequate to convert low-energy X-ray radiation (E < 25 keV - it is a range not typical for conventional X-ray systems) to visible light. Measurements obtained for different energies, exposure times, and different targets have been presented and analysed.

2

A portable fast neutron radiography system for non-destructive analysis of composite materials

Kam Erol, Reyhancan Iskender A., Biyik Recep

Nukleonika

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2019

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Vol. 64, No. 3

97--101

EN

Depending on the neutron energy used, neutron radiography can be generally categorized as fast and thermal neutron radiography. Fast neutron radiography (FNR) with neutron energy more than 1 MeV opens up a new range of possibilities for a non-destructive examination when the inspected object is thick or dense. Other traditional techniques, such as X-ray, gamma ray and thermal neutron radiography, do not meet penetration capabilities of FNR in this area. Because of these distinctive features, this technique is used in different industrial applications such as security (cargo investigation for contraband such as narcotics, explosives and illicit drugs), gas/liquid fl ow and mixing and radiography and tomography of encapsulated heavy shielded low Z compound materials. The FNR images are produced directly during exposure as neutrons create recoil protons, which activate a scintillator screen, allowing images to be collected with a computer-controlled charge-coupled device camera. Finally, the picture can be saved on a computer for image processing. The aim of this research was to set up a portable FN R system and to test it for use in non-destructive testing of different composite materials. Experiments were carried out by using a fast portative neutron generator Thermo Scientific MP 320.

3

Impact of machining conditions on exploitaion stability of thermoplastic composite scintillators

Lavrynenko S., Rucki M., Siemiątkowski Z., Kucharczyk W., Morozow D., Zapolovsky M., Lavrynenko O.

Journal of Machine Construction and Maintenance - Problemy Eksploatacji

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2018

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no. 4

47--55

EN

The paper presents research results on the degradation of scintillators made out of thermoplastic composite materials based on polystyrene (PS). The samples were machined with the tools made out of three different material types: refractory alloys, synthetic diamonds, and diamonds mined from the Earth. The investigations enabled us to establish relations between the polystyrene scintillators’ machining conditions and the final roughness of their surface, as well as the impact of the surface quality on their optical stability. It was found that optimal feed of the preliminary machining was no more than 0.1 mm/tooth, and, for profiling or finishing milling, the rate was ca. 0.02 to 0.04 mm/tooth. Both an increase and decrease of the finishing milling parameters worsened the quality of the surface. It was proved that the optical elements can keep unchanged their characteristics during exploitation as long as 10 years if certain machining conditions are kept. The result can be attributed to high surface integrity in terms of surface microcracks, edge micro-damages, and inner stresses.

PL

W artykule przedstawiono wyniki badań nad degradacją materiału scyntylatorów wykonanych z termoplastycznych kompozytów na bazie polistyrenu (PS). Badane próbki obrabiano narzędziami z różnych materiałów: ze stopów trudnotopliwych, z diamentów sztucznych oraz z diamentów naturalnych. Na podstawie wyników ustalono zależności pomiędzy warunkami obróbki scyntylatorów polistyrenowych a wynikową topografią powierzchni, a następnie pomiędzy jakością powierzchni a stabilnością optyczną scyntylatorów. Ustalono, że optymalny posów dla obróbki zgrubnej wynosił nie więcej niż 0,1 mm/ostrze, zaś dla dokładnej i wykańczającej ok. 0,02÷0,04 mm/ostrze. Zarówno zwiększenie, jak i zmniejszenie tych wielkości pogarszało jakość powierzchni. Stwierdzono, że zachowanie określonych parametrów obróbki powoduje, iż elementy optyczne mogą zachowywać swoje właściwości eksploatacyjne nawet do 10 lat, prawdopodobnie ze względu na uzyskany wysoki stopień integracji powierzchni i minimalizację mikropęknięć, mikrouszkodzeń krawędzi oraz naprężeń wewnętrznych.

4

Offset compensated baseline restoration and computationally efficient hybrid interpolation for the brain PET

Qaisar S. M.

Bio-Algorithms and Med-Systems

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2018

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Vol. 14, no. 4

art. no. 20180031

EN

The acquisition of positron emission tomography (PET) pulses introduces artifacts and limits the performance of the scanner. To minimize these inadequacies, this work focuses on the design of an offset compensated digital baseline restorer (BLR) along with a two-stage hybrid interpolator. They respectively treat the incoming pulse offsets and limited temporal resolution and improve the scanner performance in terms of calculating depth of interactions and line of responses. The offset of incoming PET pulses is compensated by the BLR and then their interesting parts are selected. The selected signal portion is up-sampled with a hybrid interpolator. It is composed of an optimized weighted least-squares interpolator (WLSI) and a simplified linear interpolator. The processes of calibrating the WLSI coefficients and characterizing the BLR and the interpolator modules are described. The functionality of the proposed modules is verified with an experimental setup. Results have shown that the devised BLR effectively compensates a dynamic range of bipolar offsets. The signal selection process allows focusing only on the relevant signal part and avoids the unnecessary operations during the post-interpolation process. Additionally, the hybrid nature allows improving the signal temporal resolution with an appropriate precession at a reduced computational complexity compared to the mono-interpolationbased arithmetically complex counterparts. The component-level architectures of the BLR and the interpolator modules are also described. It promises an efficient integration of these modules in modern PET scanners while using standard and economical analog-to-digital converters and field-programmable gate arrays. It avoids the development of high-performance and expensive application-specific integrated circuits and results in a costeffective realization.

5

Industrial X-ray testing without intermediate data carriers of information

Troitskiy V.

Badania Nieniszczące i Diagnostyka

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2018

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nr 2

29--34

EN

The new direction of radiography is Flash-radiography (FR ) which doesn’t have intermediate data carriers (films and storage plates). FR produces a quick image. It provides low testing cost, and capability of multi-angle real time internal defects monitoring of the objects. In film radiography, if relative photometric density is more than 4, then the snapshots become virtually unreadable and they can be difficult to be digitized. Current film-free technologies do not have this disadvantage and, besides, give results in a digital form without special digitizing systems. Digital data contain radiation images of internal defects, expand the flawdetection possibilities and reduce testing cost. Flash-radiography is based on portable X-ray television, which allows the observation of X-ray testing results on a monitor screen. The internal defects examination from different angles may be carried out. Flash-radiography with digital solid-state transducers is the most perspective one with sensitivity up to 0.1% of examined metal’s thickness at resolution exceeding 10 pairs of lines per mm. Application of small-size movable solid-state transducers opens new technological capabilities. They can be located and moved in the zones where positioning of film holders and storage plates is impossible. The new X-ray mini technology expands the application of NDT. The examples of practical application of solid-state miniature transducers are presented.

PL

Nowym kierunkiem radiografii jest radiografia błyskowa (ang. flash radiograpy, FR), która nie ma pośrednich nośników danych (błon i płyt pamięciowych). FR tworzy szybki obraz. Zapewnia niskie koszty testowania oraz możliwość monitorowania obiektów pod kątem błędów wewnętrznych w czasie rzeczywistym. W radiografii błonowej, jeśli względna gęstość fotometryczna jest większa niż 4, migawki stają się praktycznie nieczytelne i mogą być trudne do digitalizacji. Obecne technologie wolne od błon radiograficznych nie mają tej wady, a poza tym dają wyniki w formie cyfrowej bez specjalnych systemów do digitalizacji. Dane cyfrowe zawierają obrazy promieniowania z defektów wewnętrznych, rozszerzają możliwości wykrywania wad i zmniejszają koszty testowania. Promieniowanie błyskowe jest oparte na przenośnym aparacie rentgenowskim, który umożliwia obserwację wyników badań rentgenowskich na ekranie monitora. Można przeprowadzić badanie wad wewnętrznych pod różnymi kątami. Promieniowanie błyskowe z cyfrowymi przetwornikami półprzewodnikowymi jest najbardziej perspektywiczne z czułością na poziomie do 0,1% badanej grubości metalu przy rozdzielczości przekraczającej 10 par linii na mm. Zastosowanie przenośnych przetworników półprzewodnikowych o niewielkich rozmiarach otwiera nowe możliwości technologiczne. Można je lokalizować i przemieszczać w strefach, w których nie jest możliwe pozycjonowanie uchwytów błon i płyt do przechowywania. Nowa mini technologia rentgenowska rozszerza zastosowanie NDT. Przedstawiono przykłady praktycznego zastosowania miniaturowych przetworników półprzewodnikowych.

6

Ionizing radiation as a component of energy balance in electrical discharges in air and mineral oil

Nagi Ł.

Measurement Automation Monitoring

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2016

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Vol. 62, No. 4

146--148

EN

The paper presents the results of research concerning electrical discharges generating ionizing radiation in air and oil. Ionizing radiation is an important component of energy balance in electrical discharges. In energetics and all other engineering sciences, the energy balance shows the flow of energy for a given technological process. Within it, the energy needs of the process and its effect are collated.

7

PALS investigations of free volumes thermal expansion of J-PET plastic scintillator synthesized in polystyrene matrix

Wieczorek A., Zgardzińska B., Jasińska B., Gorgol M., Bednarski T., Białas P., Czerwiński E., Gajos A., Kamińska D., Kapłon Ł., Kochanowski A., Korcyl G., Kowalski P., Kozik T., Krzemień W., Kubicz E., Niedźwiecki S., Pałka M., Raczyński L., Rudy Z., Rundel O., Sharma N. G., Silarski M., Silarski A., Strzelecki A., Wiślicki W., Zieliński M., Moskal P.

Nukleonika

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2015

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Vol. 60, No. 4, part 1

777--781

EN

The polystyrene doped with 2,5-diphenyloxazole as a primary fluor and 2-(4-styrylphenyl)benzoxazole as a wavelength shifter prepared as a plastic scintillator was investigated using positronium probe in wide range of temperatures from 123 to 423 K. Three structural transitions at 260, 283, and 370 K were found in the material. In the o-Ps intensity dependence on temperature, the significant hysteresis is observed. Heated to 370 K, the material exhibits the o-Ps intensity variations in time.

8

Development of crystals based on cesium iodide for measurements of gamma radiation and alpha particles

Pereira M. C. C., Filho T. M., Hamada M. M.

Nukleonika

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2009

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Vol. 54, No. 3

151-155

EN

During the past 50 years, scintillators have been among the most important nuclear radiation detectors. Inorganic scintillators are widely used in experimental nuclear physics, high energy physics, nuclear medicine, nuclear tomography, environmental studies and many other fields of use. Scintillation crystals based on cesium iodide (CsI) are matters of relatively low hygroscopy, high atomic number, easy handling and low cost, characteristics that favor their use as radiation detectors. In this work, the growth of pure CsI crystals, CsI:Br and CsI:Pb, using the Bridgman technique, is described. Ions of divalent lead (Pb2+) doped in the crystal structures are efficient emission centers and their application as scintillators is still the reason for intensive studies. Recently, promising results have been found for crystals of CsI doped by bromine (Br) for their use as radiation detectors. The concentration of the bromine doping element (Br) was studied in the range from 1.5 × 10–1 M to 10–2 M and the lead (Pb) in the range from 10–2 M to 5 × 10–4 M. To evaluate the scintillators developed, systematic measurements were carried out for luminescence emission and luminescence decay time for gamma radiation, Vickers microhardness assays, and analysis of crystals response to the gamma radiation, in the energy range from 350 keV to 1330 keV, and alpha particles from a 241Am source, with energy of 5.54 MeV. The obtained values for luminescence decay time for CsI:Br and CsI:Pb crystals, were from 13 to 19 ns.

9

Growth and scintillation propertiesof Ce-doped PrF₃ single crystals

Kamada K., Yoshikawa A., Satonaga T., Sato H., Beitlerova A., Nikl M., Solovieva N., Fukuda T.

Opto-Electronics Review

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2004

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Vol. 12, No. 4

365-368

EN

The scintillation characteristics of the Ce-doped PrF₃ single crystals have been studied to find out their potential as for heavy scintillators. Crystal growth was performed in a vacuum-tight micro-pulling down (µ-PD) system. PrF₃ crystal was prepared with various concentrations (0, 0.1, 0.5, 1, 3, 5, 10, 20, 60, 80, 100%) of Ce³⁺. The crystals were transparent (CeF₃) or of greenish colour, 3 mm in diameter and 15-50 mm in length. Neither visible inclusions nor cracks were observed. At room temperature, the radio- and photoluminescence spectra and the decay kinetics were measured for the sample set.