- 标题
- 摘要
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- 实验方案
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Design and Operation of an Optically-Accessible Modular Reactor for Diagnostics of Thermal Thin Film Deposition Processes
摘要： The design and operation of a simple, optically-accessible modular reactor for probing thermal thin film deposition processes, such as atomic layer deposition processes (ALD) and chemical vapor deposition (CVD), is described. This reactor has a nominal footprint of 225 cm2 and a mass of approximately 6.6 kg, making it small enough to conveniently function as a modular component of an optical train. The design is simple, making fabrication straightforward and relatively inexpensive. Reactor operation is characterized using two infrared absorption measurements to determine exhaust times for tetrakis(dimethylamino)titanium and water, proto-typical ALD precursors, in a pressure and flow regime commonly used for ALD.
关键词： ALD,atomic layer deposition,in situ,reactor,diagnostics,chemical vapor deposition,CVD,optical cell
更新于2025-09-23 15:21:21
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Power Quality Management of PV Power Plant with Transformer Integrated Filtering Method
摘要： This paper presents a new solution of power quality management for the photovoltaic (PV) power plant with the transformer integrated filtering method. The innovation of the PV power plant is that it contains two-stage filtering station, which consists of a box-type transformer with filter and a 110 kV grid-connected transformer based on inductive filtering method. The filtering reactor can be integrated into the box-type transformer as a decoupled winding, so that the modular design of the box-type transformer and the passive filter are realized. Inductive filtering method applied transformer not only improves the power quality at the point of common coupling, but dampens the harmonic resonance between the passive filter and grid. The hierarchical structure of the PV power plant is introduced firstly. Then, the equivalent circuit model and the mathematical model of the primary filtering stations are established, and secondary respectively. Moreover, the influence of the weak coupling of integrated reactor on the filtering performance is analyzed. The antijamming capabilities of the inductive filtering method and the traditional filtering method are compared under the condition of parameter disturbance. At last, the site tests of the PV power plant with transformer integrated filtering method are made, which show that the PV grid-connected system comprised of the two-stage filtering station has the characteristics of low harmonic emission, high power factor and stable operation.
关键词： inductive filtering,Photovoltaic plant,integrated reactor,power quality
更新于2025-09-23 15:21:21
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Generation of ZnO nanoparticles for long-term exposure experiments
摘要： A method of continual ZnO nanoparticle generation was tested for use in follow-up long-term inhalation exposure experiments with small laboratory animals. Nanoparticles were synthesized in an externally heated tube reactor by the evaporation of metallic zinc into a stream of nitrogen carrier gas, followed by the oxidation of zinc vapor in a stream of air and the formation of nanoparticles by a chemical vapor condensation method. The nanoparticle production was studied at various evaporation temperatures, reactor flow rates and flow rates of mixing air. Particle generation for more than 100 h in two experimental runs with one batch of the zinc precursor was performed without a considerable decrease in the particle production rate. As a result, particle production with a number concentration much greater than 1.0 107 #/cm3, a mean particle/agglomerate size well below 50 nm and an emission rate greater than 5 μg/min was obtained under most of the investigated experimental conditions. A maximum emission rate of 16.3 μg/min was obtained at an evaporation temperature of 530 °C, a reactor flow rate of 800 cm3/min and a mixing flow rate of 2000 cm3/min and could be further increased by an increase in the evaporation temperature. The particle characteristics were studied, and estimates of the lung surface deposition area were calculated on the basis of the model developed by the International Commission of Radiological Protection.
关键词： ZnO nanoparticles,Nanoparticle generation,Evaporation/CVS method,LSDA,Hot-wall reactor
更新于2025-09-23 15:21:21
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Brazing, Laser, and Electron-Beam Welding of Additively Manufactured GRCop-84 Copper for Phased Array Lower Hybrid Launchers
摘要： Recent advances in selective laser melting 3-D printing technology allow additive manufacturing of lower hybrid current drive (LHCD) RF launchers from a new material, Glenn Research Copper 84 (GRCop-84), a Cr2Nb (8 at. % Cr, 4 at. % Nb) precipitation hardened alloy, in configurations unachievable by conventional machining. Cr2Nb crystals pin grain boundaries within the copper matrix resulting in high tensile strength and resistance to annealing at elevated temperatures. Brazing, laser, and electron-beam welding (EBW) techniques are explored for joining a thin-walled GRCop-84 waveguide with zero porosity and minimal internal surface roughness. GRCop-84 wets well with the silver solder, CuSil, and Cusil-ABA brazes, once the durable surface oxide is mechanically removed. GRCop-84 melt pool size and flow during EBW is reduced compared to oxygen-free copper (OFC). Pulsed laser and e-beam welding maintains the Cr2Nb precipitate size; precipitate coarsening occurs in conduction mode e-beam welding.
关键词： joining processes,fusion reactor design,magnetic confinement,Annealing,tokamaks,copper alloys,melt processing,materials processing,phased arrays,waveguide
更新于2025-09-23 15:21:01
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A mm <sup>3</sup> Fiber-Coupled Scintillator for In-Core Thermal Neutron Detection in CROCUS
摘要： The article presents the development, characterization and in-core testing of a miniature neutron detector for the investigation of highly localized in-core neutronics effects in the zero-power reactor CROCUS, operated at école Polytechnique fédérale de Lausanne (EPFL), Switzerland. A ZnS:6LiF screen, mixing inorganic scintillator and neutron converter, with a surface of 1 mm2 and a thickness of 0.2 mm was coupled with a silicon photomultiplier (SiPM) via a 10-m optical fiber. Analog read-out electronics were adopted in this prototype version to process the SiPM output signal. A first campaign was carried out to assess the detection system capabilities in terms of neutron detection and counting in mixed neutron-gamma radiation fields. The miniature detector was thoroughly characterized with a Pu-Be source installed in the CARROUSEL facility, and subsequently tested inside a control rod guide tube of the CROCUS reactor in different reactor conditions, i.e. at shutdown, startup and critical. The detector shows a linear response with the reactor power increase up to 6.5 W (i.e. around 108 cm-2·s-1 total neutron flux) and excellent neutron counting capabilities when compared to other localized detection systems available in CROCUS, such as miniature fission chambers and sCVD diamond detectors. In addition, the exposure of the miniature detector to a 60Co source with an activity of ～250 GBq, combined with the computation of the gamma flux in CROCUS with the Serpent 2 Monte Carlo code, confirmed the gamma insensitivity of the system in a mixed neutron-gamma field.
关键词： miniature neutron detector,CROCUS zero-power reactor,optical fiber devices,in-core neutron detectors,miniature scintillator devices
更新于2025-09-23 15:21:01
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MeV photon imaging with robotic sample positioning at a research reactor
摘要： This paper summarizes the development and demonstration of an X-ray and gamma-ray radiography capability using a TRIGA MARK-II reactor. Photons are a combination of Bremsstrahlung X-rays and gamma rays from fission and radioactive decay. The energy spectrum of the facility was analyzed with a NaI(Tl) scintillator detector. A digital X-ray camera for use with MeV-range photons images a duplex wire-type penetrameter to analyze unsharpness and spatial resolution. An industrial manipulator precisely positions the sample, which allows objects to have larger dimensions than the detector’s field-of-view. Future work includes performing computed tomography to create 3-dimensional representations of objects.
关键词： Nuclear research reactor,Gamma,X-ray,Non-destructive testing,Radiation imaging,Robotics
更新于2025-09-23 15:21:01
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Metal Vapor Lasers
摘要： The milestones in the development of researches connected with metal vapor lasers, which have been carried out at V.E. Zuev Institute of Atmospheric Optics, Siberian Branch, Russian Academy of Sciences, since its first days are considered. Some of the most interesting fundamental and applied results are presented. A fairly extensive list of related works, published mainly in the past twenty years, is given.
关键词： brightness amplifier,active thermal insulation,active impurity generator,optical pumping,metal vapor lasers,laser efficiency,metal halides,active optical systems,inner reactor
更新于2025-09-23 15:19:57
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Heat transfer model of a 50 kW solar receiver-reactor for thermochemical redox cycling using cerium dioxide
摘要： This work reports on the development of a transient heat transfer model of a solar receiver-reactor designed for thermochemical redox cycling by temperature and pressure swing of pure cerium dioxide in the form of a reticulated porous ceramic (RPC). In the first, endothermal, step the cerium dioxide RPC is directly heated with concentrated solar radiation to 1500 °C while under vacuum pressure of less than 10 mbar, thereby releasing oxygen from its crystal lattice. In the subsequent, exothermic, step the reactor is re-pressurized with carbon dioxide as it cools, and at temperatures below 1000 °C the partially reduced cerium dioxide is re-oxidized with a flow of carbon dioxide. To analyze the performance of the solar reactor and to gain insight into improved design and operational conditions, a transient heat transfer model of the solar reactor for a solar radiative input power of 50 kW during the reduction step was developed and implemented in ANSYS CFX. The numerical model couples the incoming concentrated solar radiation using Monte-Carlo ray tracing, incorporates the reduction chemistry by assuming thermodynamic equilibrium, and accounts for internal radiation heat transfer inside the porous ceria by applying effective heat transfer properties. The model was experimentally validated using data acquired in a high-flux solar simulator, where temperature evolution and oxygen production results from model and experiment agreed well. The numerical results indicate the prominent influence of solar radiative input power, where increasing it substantially reduces reduction time of the cerium dioxide structure. Consequently, the model predicts a solar-to-fuel energy conversion efficiency of > 6% at a solar radiative power input of 50 kW; efficiency > 10% can be obtained provided the RPC macro porosity is substantially increased and better volumetric absorption and uniform heating is achieved. Managing the ceria surface temperature during reduction to avoid sublimation is a critical design consideration for direct absorption solar receiver-reactors.
关键词： design optimization,reactor modelling,ceria,thermochemical cycles,solar energy,reticulated porous ceramic
更新于2025-09-23 15:19:57
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Manufacturing Graphene-Encapsulated Copper Particles by Chemical Vapor Deposition in a Cold Wall Reactor
摘要： Functional fillers, such as Ag, are commonly employed for effectively improving the thermal or electrical conductivity in polymer composites. However, a disadvantage of such a strategy is that the cost and performance cannot be balanced simultaneously. Therefore, the drive to find a material with both a cost efficient fabrication process and excellent performance attracts intense research interest. In this work, inspired by the core–shell structure, we developed a facile manufacturing method to prepare graphene-encapsulated Cu nanoparticles (GCPs) through utilizing an improved chemical vapor deposition (CVD) system with a cold wall reactor. The obtained GCPs could retain their spherical shape and exhibited an outstanding thermal stability up to 179 °C. Owing to the superior thermal conductivity of graphene and excellent oxidation resistance of GCPs, the produced GCPs are practically used in a thermally conductive adhesive (TCA), which commonly consists of Ag as the functional filler. Measurement shows a substantial 74.6 % improvement by partial replacement of Ag with GCPs.
关键词： graphene,copper particles,cold wall reactor,thermal conductivity,oxidation resistance
更新于2025-09-19 17:15:36
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Hydrogen and Oxygen Evolution in a Membrane Photoreactor Using Suspended Nanosized Au/TiO2 and Au/CeO2
摘要： Photocatalysis combined with membrane technology could offer an enormous potential for power generation in a renewable and sustainable way. Herein, we describe the one-step hydrogen and oxygen evolution through a photocatalytic membrane reactor. Experimental tests were carried out by means of a two-compartment cell in which a modified Nafion membrane separated the oxygen and hydrogen evolution semi-cells, while iron ions permeating through the membrane acted as a redox mediator. Nanosized Au/TiO2 and Au/CeO2 were employed as suspended photocatalysts for hydrogen and oxygen generation, respectively. The influence of initial Fe3+ ion concentration, ranging from 5 to 20 mM, was investigated, and the best results in terms of hydrogen and oxygen evolution were registered by working with 5 mM Fe3+. The positive effect of gold on the overall water splitting was confirmed by comparing the photocatalytic results obtained with the modified/unmodified titania and ceria. Au-loading played a key role for controlling the photocatalytic activity, and the optimal percentage for hydrogen and oxygen generation was 0.25 wt%. Under irradiation with visible light, hydrogen and oxygen were produced in stoichiometric amounts. The crucial role of the couple Fe3+/Fe2+ and of the membrane on the performance of the overall photocatalytic system was found.
关键词： water splitting,photocatalytic membrane reactor,photocatalysis,Z-scheme
更新于2025-09-19 17:15:36