- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Nickel doped TiO <sub/>2</sub> films by a modified laser plasma source for photocatalytic applications
摘要： We reports a study on pure and Ni-doped TiO2 thin ?lms produced via laser ablation technique. The novelty of the work consists that both synthesis and doping were carried out in a single process, using a modi?ed laser ion source to simultaneously make pulsed laser deposition (PLD) and low-energy ion implantation (by post-acceleration method). In particular, two titania ?lms were synthesized via PLD starting from a rutile target. One of the two ?lms was doped with Ni ions, accelerated with a voltage of 20 kV. The total implanted dose, evaluated by a Faraday cup, resulted to be 1 × 1014 ions/cm2. The crystalline phase of the obtained TiO2 ?lms was analysed by Raman spectroscopy. A higher photocatalytic activity, measured under UV irradiation using methylene blue, was estimated for the Ni-doped titania ?lm with respect the pure one.
关键词： Plasma generation (laser-produced, RF, x ray-produced),Accelerator Applications,Plasma diagnostics - probes
更新于2025-09-23 15:21:01
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A Multiport Converter Interfacing Solar Photovoltaic Modules and Energy Storage with DC Microgrid
摘要： A novel real-time optical fibre X-Ray dosimeter for monitoring the radiation pulses delivered from a clinical linear accelerator (Linac) is presented. The primary focus of the sensor is to measure low doses of ionising X-ray radiation in real time (limited to 0.1-ms gate time of the detector). The sensor tip material scintillates upon exposure to X-ray energy and the resultant low-level visible light signal is coupled to a polymethyl methacrylate plastic optical fibre, which is used to guide it towards a distal avalanche photodiode-based detector. The detector measures the low-level scintillating light from the sensor, thereby converting the ionizing radiation energy to a measurable signal with a time resolution of 0.1 ms. Results show that the scintillating optical fibre X-ray dosimeter is capable of capturing the individual X-Ray pulses delivered by the Linac during normal operation. Further examination of the results demonstrates that the sensor is capable of measuring dose rate and, hence, dose with a linearity (R2 = 0.9995 ? 0.9999) and in a highly repeatable manner for dose rates in the range 100 to 600 monitor units/min.
关键词： optical fibre sensors,X-ray dosimetry,Clinical external beam radiotherapy,fluorescent and luminescent sensors,real time radiation dose measurement
更新于2025-09-23 15:21:01
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Characterisation of elemental analysis, carbon sulphur analysis and impact test of stent manufacturing using medical grade ASTM F75 cobalt chromium (CoCrMo) by selective laser melting (SLM) technology
摘要： This paper explains and demonstrates the capabilities of metal additive manufacturing (MAM) technology in producing intricate stent structure with a customise design by using ASTM F75 cobalt chromium powder. The elemental analysis (EDX-SEM), carbon sulphur analysis and Impact Test are being develop and tested and thus exploring the potential area of MAM process for future proof stent manufacturing. By alternatively switching to MAM, the step of production can be minimised and thus customisation of stent can be carried out according to the patient’s need. The suggested model of the stent was taken from the third-party vendor and fabrication was carried out using EOSINT M280 metal printer with the aid of Materialise Magics 19.0 software for support generation.
关键词： stent,scanning electron microscope (SEM),selective laser melting (SLM),cobalt chromium (CoCrMo),energy-dispersive X-ray spectroscopy (EDX),Metal additive manufacturing (MAM)
更新于2025-09-23 15:21:01
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Biocompatible nanoparticles production by pulsed laser ablation in liquids
摘要： The preparation of spherical metallic nanoparticles (NPs), in the range of 10–100 nm, using pulsed laser ablation in water has particular interest in many scienti?c ?elds. The fast released laser energy to the solid metal in water produces plasma at the solid-liquid interface generating NPs in solution. The size distribution and the solution concentration depend by many parameters concerning the laser source (wavelength, pulse energy, pulse duration), the irradiation conditions (target depth in water, focal spot, repetition rate, irradiation time), and the medium where the ablation occurs (water, solution concentration, presence of surfactants). Optimal conditions can be found to control the average particle size, the size distribution, and the coalescence e?ect. A study of the NPs dependence from the ns pulsed Nd:YAG laser, irradiating metals in water is presented, discussing also the physical characterization of the produced NPs employing microscopy and optical analyses.
关键词： Plasma generation (laser-produced, RF, x ray-produced),Lasers
更新于2025-09-23 15:21:01
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Laguerre-Gaussian Mode Laser Heater for Microbunching Instability Suppression in Free-Electron Lasers
摘要： Microbunching instability (MBI) driven by beam collective effects is known to be detrimental to high-brightness storage rings, linacs, and free-electron lasers (FELs). One known way to suppress this instability is to induce a small amount of energy spread to an electron beam by a laser heater. The distribution of the induced energy spread greatly affects MBI suppression and can be controlled by shaping the transverse profile of the heater laser. Here, we present the first experimental demonstration of effective MBI suppression using a LG01 transverse laser mode and compare the improved results with respect to traditional Gaussian transverse laser mode at the Linac Coherent Light Source. The effects on MBI suppression are characterized by multiple downstream measurements, including longitudinal phase space analysis and coherent radiation spectroscopy. We also discuss the role of LG01 shaping in soft x-ray self-seeded FEL emission, one of the most advanced operation modes of a FEL for which controlled suppression of MBI is critical.
关键词： Free-electron lasers,Microbunching instability,LG01 mode,Laser heater,Soft x-ray self-seeded FEL,Gaussian mode,MBI suppression
更新于2025-09-23 15:21:01
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Combined temperature and radiation effects on radiation sensitive single-mode optical fibers
摘要： A novel real-time optical fibre X-Ray dosimeter for monitoring the radiation pulses delivered from a clinical linear accelerator (Linac) is presented. The primary focus of the sensor is to measure low doses of ionising X-ray radiation in real time (limited to 0.1-ms gate time of the detector). The sensor tip material scintillates upon exposure to X-ray energy and the resultant low-level visible light signal is coupled to a polymethyl methacrylate plastic optical fibre, which is used to guide it towards a distal avalanche photodiode-based detector. The detector measures the low-level scintillating light from the sensor, thereby converting the ionizing radiation energy to a measurable signal with a time resolution of 0.1 ms. Results show that the scintillating optical fibre X-ray dosimeter is capable of capturing the individual X-Ray pulses delivered by the Linac during normal operation. Further examination of the results demonstrates that the sensor is capable of measuring dose rate and, hence, dose with a linearity (R2 = 0.9995 ? 0.9999) and in a highly repeatable manner for dose rates in the range 100 to 600 monitor units/min.
关键词： optical fibre sensors,X-ray dosimetry,Clinical external beam radiotherapy,fluorescent and luminescent sensors,real time radiation dose measurement
更新于2025-09-23 15:21:01
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Dependence of macro-bending loss on bending configuration of multimode optical fibers studied by ray-tracing simulation
摘要： The macro-bending loss of multimode step-index helical, s-shaped, and figure-of-eight-shaped optical fibers is investigated by ray-tracing simulation. In particular, fibers with the same radius of curvature having the three different configurations are compared. It is found that macro-bending loss strongly depends on the configuration as well as the bending curvature of the fibers. For the same curvature, the macro-bending loss of fibers in different configurations differs markedly. Thus, when comparing or reporting the macro-bending loss of multimode optical fibers, it is necessary to specify the bending radius as well as the fiber configuration.
关键词： Ray-tracing simulation,Macro-bending loss,Optical fiber
更新于2025-09-23 15:21:01
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Development of a predictive capability of short-pulse laser-driven broadband x-ray radiography
摘要： High intensity, short-pulse laser interaction with a solid metal target produces broadband hard x rays potentially for various applications of x-ray radiography. Here experimental benchmarking of numerical modelling for short-pulse laser-driven broadband x-ray radiography is presented. Angular dependent x-ray spectra are first calculated with a hybrid particle-in-cell code, Large Scale Plasma (LSP), using fast electron parameters inferred from an analysis of measured bremsstrahlung signals. Subsequently, a calculated x-ray spectrum in the direction of radiography is used in photon transport calculations using a Monte Carlo code, Particle and Heavy Ion Transport code System (PHITS), to simulate a radiographic image including a modelled 3D test object, an x-ray attenuation filter and an image plate detector. Simulated radiographic images are compared with measurements obtained in an experiment using a 50-TW Leopard short-pulse laser at the University of Nevada Reno. Results show that simulations reproduce the experimental images well for three different attenuation filters (plastic, aluminium, and brass), while one-dimensional transmission profiles for the plastic and aluminium filters are quantitatively in good agreement. The modelling approach established in this work could be used as a predictive tool to simulate radiographic images of complex 3D solid objects at any arbitrary angular position or to optimize experimental components such as the source spectrum, x-ray attenuation filters and a detector type depending on a radiographic object without carrying out radiographic experiments.
关键词： Monte Carlo simulations,hybrid particle-in-cell,broadband x-ray radiography,short-pulse laser-produced x rays
更新于2025-09-23 15:21:01
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[IEEE 2019 8th International Congress on Advanced Applied Informatics (IIAI-AAI) - Toyama, Japan (2019.7.7-2019.7.11)] 2019 8th International Congress on Advanced Applied Informatics (IIAI-AAI) - Phase Type Special-Purpose Computer for Electroholography in Embedded Systems
摘要： This paper is the fifth in a series of articles on the basic physics of light yield nonproportionality in scintillators. Here, we compare and contrast the nonproportionality as registered by gamma rays and high-energy electrons. As has been noted in the past, these two types of data have different curve shapes (for plots of the light yield against electron or gamma energy). Herein, we show how the experimental gamma nonproportionality curve can be calculated from the electron response by accounting for the distribution of high energy electrons created by the gamma photon via the photoelectric interaction. Similarly, we measure and model the gamma-induced resolution as a function of energy and compare this data to predictions from our model. The utility of the model is explored using data acquired with the scintillators (Eu), GYGAG(Ce) and CsI(Na).
关键词： Gamma ray detectors,solid scintillation detectors,luminescence
更新于2025-09-23 15:21:01
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Spectroscopic Studies of M??ssbauer, Infrared, and Laser-Induced Luminescence for Classifying Rare-Earth Minerals Enriched in Iron-Rich Deposits
摘要： Rare-earth (RE) phosphates often appear as an accessory phase in igneous or metamorphic rocks; however, these rocks are composed of myriad chemical elements and nuclides that interfere with the qualitative or quantitative analyses of the RE phosphates over a range of concentrations in the absence of a pretreatment. In addition, the limit of each analytical methodology constrains the approach as well as the usefulness of the results in geoscience applications. Here, we report the specific mineral characterization of RE-containing ores from Yen Phu mine, Vietnam, using a range of state-of-the-art spectroscopic techniques in conjunction with microscopy: M?ssbauer spectroscopy, infrared microspectroscopy, time-resolved laser-induced fluorescence spectroscopy (TRLFS), and scanning electron microscopy with energy-dispersive X-ray spectroscopy. Because the distribution of each element in the deposit differs, such combinatorial works are necessary and could lead to more plausible answers to questions surrounding the point of origin of RE elements. The results of our M?ssbauer spectroscopic analysis indicate that the three ores sampled at different locations all contain magnetite-like, hematite-like, and iron(III) salts other than hematite. In addition, we confirmed the presence of phosphate around the grain boundary in the magnetite-like mineral phase by infrared microspectroscopic analysis. The present analytical findings of trace amounts of europium(III) using TRLFS suggest that the europium ions generate identical luminescence spectra despite being embedded in three different matrices of iron minerals. This demonstration highlights the benefits of combinatorial spectroscopic analyses to gain insights into the effects of the environment of REs on their solid-state chemistry and shows the potential utility of TRLFS as a resource mining tool. Further applications of this approach in the analytical screening of rocks and minerals are feasible.
关键词： energy-dispersive X-ray spectroscopy,spectroscopic techniques,rare-earth phosphates,Yen Phu mine,infrared microspectroscopy,scanning electron microscopy,time-resolved laser-induced fluorescence spectroscopy,M?ssbauer spectroscopy,Vietnam
更新于2025-09-23 15:21:01