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Performance characterisation of a real-time fiber dosimetry system using radiophotoluminescent glasses
摘要： We report the first demonstration of a real-time fiber-optic-coupled dosimetry system using Ag-activated phosphate glasses based on radiophotoluminescent (RPL) phenomena. The performance characterisation using real-time fiber RPL glass dosimetry is compared with that of real-time fiber plastic scintillation dosimetry. The inevitable build-up phenomena occurring in Ag-activated RPL glasses both during and after X-ray exposure were measured. The real-time RPL curves for the X-ray exposure region and the build-up region are analytically evaluated and fitted to the second-order polynomial functions and the sum of three exponentials, respectively. In addition, some resolved problems of real-time fiber RPL glass dosimetry are discussed.
关键词： X-ray exposure,real-time fiber dosimetry,build-up phenomena,radiophotoluminescent glasses,Ag-activated phosphate glasses
更新于2025-09-09 09:28:46
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DESIGN OF NONUNIFORM METALLIC ANECHOIC CHAMBER FOR RADIATION PATTERN MEASUREMENT
摘要： Antenna pattern measurement is an essential step in antenna quali?cation which should be done in anechoic chambers. The common method for construction of the anechoic chamber is to cover all inside walls by the electromagnetic absorbers. In this paper, a new method is presented to design a fully metallic chamber by controlling the electromagnetic wave propagation inside the chamber and guiding them to a piece of absorber. Therefore, a desirable quiet zone is formed inside the chamber while a great reduction of absorber usage is achieved. The proposed chamber is analyzed using ray tracing method, and its performance is evaluated by simulation which shows the practicality of the proposed chamber.
关键词： anechoic chamber,ray tracing method,antenna pattern measurement,electromagnetic absorbers,quiet zone
更新于2025-09-09 09:28:46
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Location of water in fresh sugarcane bagasse observed by synchrotron X-ray microtomography
摘要： Sugarcane bagasse is a vast lignocellulosic byproduct generated in the industry with ~50% humidity (1 kg dry matter associated with 1 kg water). Although the presence of water brings deleterious consequences for combustion, storage and sugar extraction, the location of water in fresh bagasse remains unknown. In this work, we use synchrotron X-ray microtomography for non-invasive 3D imaging of fresh bagasse particles, which allows the visualization of intraparticle water. The sclerified fiber cells in the sheaths surrounding xylem vessels are often found full of water. We suggest this can be juice preserved from the native stalks as many sclerified fibers seem to keep their structural integrity despite the mechanical action during sugarcane crushing. The microtomograms of fresh bagasse also shows mineral particles adhered to biomass surfaces, with adhesion presumably favored by the presence of water. In summary, this work unveils the location of water in fresh bagasse, solving an old mystery of sugarcane technology.
关键词： synchrotron X-ray microtomography,juice preservation,sugarcane bagasse,lignocellulosic byproduct,water location
更新于2025-09-09 09:28:46
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Studies on zinc oxide thin films by chemical spray pyrolysis technique
摘要： Zinc oxide (ZnO) thin films were deposited by chemical spray pyrolysis (CSP) technique using zinc acetate dihydrate solutions on microscopic glass substrates by varying the precursor concentration. The prepared films were characterized structurally and optically, using the powder X-ray diffraction (XRD) and UV analysis and Photoluminescence analysis. Crystallographic properties were analyzed through powder XRD. The XRD patterns shows a hexagonal structure with c-axis orientation (0 0 2) on self texturing phenomenon. Optical transmittance properties of the optimized ZnO thin films were investigated by using UV-Vis spectroscopy. The optical studies predicated a maximum transmittance in the range of above 70% with direct band gap values in the range of 2.9 to 3.2eV for the zinc oxide thin films. Under excitation of 300 nm radiations, sharp deep level emission peak at 2.506 eV dominates the photoluminescence spectra with weak deep level and near band edge emission peak at 3.026 and 3.427 eV respectively.
关键词： Photoluminescence,Transparent conducting oxide (TCO),UV-Vis,Zinc Oxide thin film,CSP technique,X-ray diffraction (XRD)
更新于2025-09-09 09:28:46
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Boosting Direct X-Ray Detection in Organic Thin Films by Small Molecules Tailoring
摘要： The attention focused on the application of organic electronics for the detection of ionizing radiation is rapidly growing among the international scientific community, due to the great potential of organic technology to enable large-area conformable sensor panels. However, high-energy photon absorption is challenging as organic materials are constituted of atoms with low atomic numbers. Here it is reported how, by synthesizing new solution-processable organic molecules derived from 6,13-bis(triisopropylsilylethynyl)pentacene (TIPS-pentacene) and 2,8-difluoro-5,11-bis(triethylsilylethynyl)anthradithiophene, with Ge-substitution in place of the Si atoms to increase the material atomic number, it is possible to boost the X-ray detection performance of organic thin films on flexible plastic substrates. Bis(triisopropylgermylethynyl)-pentacene based flexible organic thin film transistors show high electrical performance with higher mobility (0.4 cm2 V?1 s?1) and enhanced X-ray sensitivity, up to 9.0 × 105 μC Gy?1 cm?3, with respect to TIPS-pentacene-based detectors. Moreover, similar results are obtained for 5,11-bis(triethylgermylethynyl)anthradithiophene devices, confirming that the proposed strategy, that is, increasing the atomic number of organic molecules by chemical tailoring to improve X-ray sensitivity, can be generalized to organic thin film detectors, combining high X-ray absorption, mechanical flexibility, and large-area processing.
关键词： organic X-ray detectors,thin film transistors,TIPS-pentacene,TIPGe-pentacene
更新于2025-09-09 09:28:46
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Experimental Investigations of Phase Equilibria in Ternary Ag-Cu-Ga System
摘要： Experimental study of phase equilibria in the ternary Ag-Cu-Ga system was carried out by using DTA/DSC, isothermal equilibration and microscopic as well as x-ray analyses. DTA experiments were conducted for alloys, whose concentrations varied along two cross-sections determined by the ratio of mole fractions xAg/xCu = 1:1 and xAg/xGa = 1:1. Equilibration of samples was carried out at 200, 450 and 650 (cid:3)C. The obtained information about phases in equilibrium was compared with the results of calculations of the phase diagram for conditions identical to our experiments. It was demonstrated that the results of calculations are compatible with the experimental data.
关键词： CALPHAD method,x-ray diffraction,DTA measurements,Ag-Cu-Ga system,phase equilibria,scanning electron microscopy
更新于2025-09-09 09:28:46
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Influencing Optical and Magnetic Properties of NiCr2O4 by the Incorporation of Fe(III) for Cr(III) Following Epoxide Gel Synthesis
摘要： With the objective of modifying the optical and magnetic properties of the spinel NiCr2O4, incorporation of 50 mol.% of Fe3+ for Cr3+ has been attempted following an epoxide-mediated gel synthesis. From the Le Bail re?nement of powder x-ray diffraction patterns of xerogels after calcination at 1000°C for 2 h in Fd-3 m space group, the lattice parameter of resultant spinels showed a marginal increase from 8.3117 (21) for NiCr2O4 to 8.3177 (26) A? for NiCrFeO4. The square morphology of the crystallites was observed in scanning electron microscopic images, and the energy-dispersive spectroscopy results con?rmed the uniform presence of Ni, Cr and Fe in these samples. Lattice fringes in high-resolution transmission electron microscopic images could be related to the cubic spinel structure. The optical band gap was found to decrease from 1.68 for NiCr2O4 to 1.41 eV for NiCrFeO4. Substitution of iron for chromium was found to reduce its catalytic ef?ciency for photo-degradation of aqueous rhodamine-6G (Rh-6G) dye solution under UV–visible radiation.
关键词： x-ray methods,Spinels,magnetic properties,calcination,sol–gel processes
更新于2025-09-09 09:28:46
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Optical performance analysis of an innovative linear focus secondary trough solar concentrating system
摘要： The parabolic trough solar concentrating system has been well developed and widely used in commercial solar thermal power plants. However, the conventional system has its drawbacks when connecting receiver tube parts and enhancing the concentration ratio. To overcome those inherent disadvantages, in this paper, an innovative concept of linear focus secondary trough concentrating system was proposed, which consists of a fixed parabolic trough concentrator, one or more heliostats, and a fixed tube receiver. The proposed system not only avoids the end loss and connection problem on the receiver during the tracking process but also opens up the possibility to increase the concentration ratio by enlarging aperture. The design scheme of the proposed system was elaborated in detail in this paper. Besides, the optical performance of the semi and the whole secondary solar trough concentrator was evaluated by using the ray tracing method. This innovative solar concentrating system shows a high application value as a solar energy experimental device.
关键词： secondary parabolic trough solar concentrator,optical performance,concentration ratio,linear focus,ray tracing method
更新于2025-09-09 09:28:46
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Superlattice-enhanced silicon soft X-ray and charged particle detectors with nanosecond time response
摘要： Silicon detectors are an essential measurement tool for Inertial Confinement Fusion and High-Energy-Density Physics Applications, where temporal response of the order of nanoseconds is essential. Soft X-rays (<1 keV), Ultraviolet light, and low-energy electrons (<10 keV) can provide essential information in diagnosing rapidly changing plasma conditions, but reducing the detector dead layer is essential to improving detector response for these shallowly absorbed particles. This paper details a study of silicon detector surface preparation methods such as ion implant parameters, and the addition of a quantum 2D superlattice, to produce fast detectors that are highly sensitive to shallowly absorbed radiation. Measurements of visible light quantum efficiency, electron responsivity, and pulsed x-ray response indicate that detectors with a 2-layer superlattice enjoy a significant benefit over equivalent detectors using an ion implant at the illuminated surface.
关键词： Pulsed power,ICF,HED physics,Silicon detectors,Electron detectors,Soft X-ray detectors
更新于2025-09-09 09:28:46
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Application of confocal X-ray fluorescence based on capillary X-ray optics in nondestructively measuring the inner diameter of monocapillary optics
摘要： The inner diameter is an important parameter in the design and fabrication of monocapillary X-ray optics which is widely used in X-ray technology. The confocal X-ray fluorescence(CXRF) based on X-ray capillary optics was proposed to nondestructively measure the inner diameter of the monocapillary. The zinc chlorine solutions were filled into monocapillary in order to measure its inner diameter with the CXRF. With a scan of the edge of zinc solutions in a monocapillary optic through the confocal volume of the CXRF, the inner diameter could be obtained directly and nondestructively. The mean of relative errors of this method for measuring the inner diameter were approximately 4.1%. This proposed method of determining the inner diameter of monocapillary optics plays a significant role in design, fabrication and application of the monocapillary X-ray optics.
关键词： Confocal X-ray fluorescence,Nondestructive,Measurement of inner diameter of monocapillary
更新于2025-09-09 09:28:46