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The Core-Plasma CXRS Diagnostic for ITER: An Introduction to the Current Design
摘要： The development and design of the CXRS diagnostic for the core plasma of ITER is used as a pretext to elaborate on several of the main challenges of optical diagnostics on such a large fusion device. The idea was to confront the students of the 16th Ettore Majorana School on Diagnostics and Technology Developments with as many aspects of the design of optical diagnostics as possible. After an elementary review of the basics of charge-exchange, of typical spectra, of intended measurements and of the expected associated background, the DNB (diagnostic neutral beam) is briefly presented. The light collection and transport to the ex-vessel fibres and spectrometers constitutes the main part of this contribution: building on existing telescope and endoscope systems, the choice of a suitable optical layout for the core-plasma CXRS diagnostic at ITER is discussed. An account follows of the protective measures against the degradation of the first mirror, which will be exposed to high particle and heat fluxes: an appropriate duct, a shutter and, possibly, a cleaning discharge with ''End-of-Cleaning Indicator''.
关键词： ITER,Diagnostics,Charge-exchange,Tokamak
更新于2025-09-23 15:22:29
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Spatial heterodyne spectroscopy for high speed measurements of Stark split neutral beam emission in a high temperature plasma
摘要： Measurement of electrostatic potential, or local electric field, turbulence is a critical missing component in validating nonlinear turbulence and transport simulations of fusion plasmas. A novel diagnostic is being developed for measuring local electric field fluctuations, ?E(r, t), via high-speed measurements of the light emitted from a hydrogenic neutral beam. It exploits the proportionality of the spectral line splitting from the Motional Stark Effect to the total electric field experienced by the neutral atom at the excitation site. The measurement is localized by the usual cross-beam geometry of beam-spectroscopy measurements. The corner stone of the diagnostic is a high spectral resolution, high etendue spatial heterodyne spectrometer (SHS). A SHS design with high etendue (～5 mm2 sr) and resolution (～0.14 nm) meets the formidable spectrometer requirements. Field tests of the spectrometer at the DIII-D tokamak demonstrate that the beam emission spectrum produced by the SHS agrees with that of a traditional spectrometer and that the measured flux is adequate for turbulence studies.
关键词： Stark split neutral beam emission,electric field fluctuations,spatial heterodyne spectroscopy,turbulence diagnostics,high temperature plasma
更新于2025-09-23 15:21:21
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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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Method of Photoplethysmography Diagnostics of Domesticated Animals Cardiovascular Diseases
摘要： At present time the standard procedure to diagnose cardiovascular diseases (CVD) of domesticated animals (dogs) is electrocardiography (ECG) monitoring at animal clinic. Sadly, results, obtained that way, are often mistaken because of stressful state of the animal, caused by medical manipulations [1]. The usage of photoplethysmography (PPG) method can become a good substitute for CVD monitoring. Main advantages of PPG, in compare with ECG, are single probe placement (on the ear or tailset), no need of gel electrodes and capability of measuring actual CVS parameters without need of special medical training or laboratory conditions. It is one of non-invasive methods for measuring the amount of the blood volume changes inside the blood vessels, applicable for cardio activity estimation by calculating heart rate variability. In most cases, PPG monitoring devises are small, easy to place and can monitor different physiological parameters of the animal, such as heart rate, pulse wave characteristics, blood oxygen saturation, etc.
关键词： Photoplethysmography,Health monitoring systems,Cardiovascular diseases,Pulse wave,Remote diagnostics
更新于2025-09-23 15:21:21
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Picomolar Biosensing and Conformational Analysis Using Artificial Bidomain Proteins and Terbiuma??Toa??Quantum Dot F??rster Resonance Energy Transfer
摘要： Although antibodies remain a primary recognition element in all forms of biosensing, functional limitations arising from their size, stability, and structure have motivated the development and production of many different artificial scaffold proteins for biological recognition. However, implementing such artificial binders into functional high-performance biosensors remains a challenging task. Here, we present the design and application of F?rster resonance energy transfer (FRET) nanoprobes comprised of small artificial proteins (αRep bidomains) labeled with a Tb complex (Tb) donor on the C-terminus and a semiconductor quantum dot (QD) acceptor on the N-terminus. Specific binding of one or two protein targets to the αReps induced a conformational change that could be detected by time-resolved Tb-to-QD FRET. These single-probe FRET-switches were used in a separation-free solution-phase assay to quantify different protein targets at subnanomolar concentrations and measure the conformational changes with subnanometer resolution. Probing ligand-receptor binding under physiological conditions at very low concentrations in solution is a special feature of FRET that can be efficiently combined with other structural characterization methods to develop, understand, and optimize artificial biosensors. Our results suggest that the αRep FRET nanoprobes have a strong potential for their application in advanced diagnostics and intracellular live cell imaging of ligand-receptor interactions.
关键词： protein structure,molecular ruler,lanthanides,molecular diagnostics,FRET,binding assay
更新于2025-09-23 15:21:01
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Laser-inscribed contact lens sensors for the detection of analytes in the tear fluid
摘要： Tears exhibit compositional variations as a response to ocular and systemic metabolic conditions, and they can therefore be used for the assessment of physiological health. Here, microfluidic contact lenses were developed as wearable platforms for in situ tear pH, glucose, protein, and nitrite ions sensing. The microfluidic system was inscribed in commercial contact lenses by CO2 laser ablation. The microchannel consisted on a central ring with four branches, and biosensors were embedded within microcavities located at the branches ends. The device was tested with artificial tears and colorimetric readouts were performed using a smartphone-MATLAB algorithm based on the nearest neighbor model. Sensors responded within a time range of 15 seconds, and yielded sensitivities of 12.23 nm/pH unit, 1.4 nm/mmolL-1 of glucose, 0.49 nm/gL-1 of proteins, and 0.03nm/μmolL-1 of nitrites. Contact lens sensing platforms may provide on-eye tears screening with applications in the monitoring of the ocular health both in clinics and at point-of-care settings.
关键词： biomarkers,biosensors,tear fluid,Contact Lenses,point-of-care diagnostics
更新于2025-09-23 15:21:01
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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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Experimental Study of Thermomechanical Processes: Laser Welding and Melting of a Powder Bed
摘要： In this study, an experimental approach was developed to analyze and better understand the laser welding and melting of a powder bed process. Different optical diagnostics tools (high-speed camera, infrared camera, pyrometer, etc.) were applied to measure different physical quantities (molten pool morphology, temperature ?eld, residual stresses, and distortions). As a result, measurements during the laser welding process facilitated the building of a database of experimental results (experimental benchmarks). The study of the melting of a powder bed enabled a better understanding of the physics related to the formation and behavior of the molten pool. These results can be used by researchers to improve and validate numerical simulations of these processes.
关键词： optical diagnostics,molten pool,melting of a powder bed,residual stresses,laser welding,temperature field
更新于2025-09-23 15:21:01
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Unimolecular FRET sensors: Simple linker designs and properties
摘要： Protein activation and deactivation is central to a variety of biological mechanisms, including cellular signaling and transport. Unimolecular fluorescent resonance energy transfer (FRET) probes are a class of fusion protein sensors that allow biologists to visualize using an optical microscope whether specific proteins are activated due to the presence nearby of small drug-like signaling molecules, ligands or analytes. Often such probes comprise a donor fluorescent protein attached to a ligand binding domain, a sensor or reporter domain attached to the acceptor fluorescent protein, with these ligand binding and sensor domains connected by a protein linker. Various choices of linker type are possible ranging from highly flexible proteins to hinge-like proteins. It is also possible to select donor and acceptor pairs according to their corresponding F¨oster radius, or even to mutate binding and sensor domains so as to change their binding energy in the activated or inactivated states. The focus of the present work is the exploration through simulation of the impact of such choices on sensor performance.
关键词： FRET Microscopy,Fusion Proteins,Diagnostics,Monte Carlo Simulation,Coarse Graining,Cellular Signaling
更新于2025-09-23 15:21:01
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Diagnostics of peak laser intensity by pair production from thin foil target
摘要： It is known that in the small quantum parameter regime the Breit-Wheeler electron-positron pair creation cross section is extremely sensitive on the photon energy and on the background field. We present the dependence of positron yield on laser intensity in laser-foil interactions with the help of analytical theory and particle-in-cell simulaitons. These particles are emitted in a relatively narrow range of cone angles close to perpendicular direction relative to the laser beam axis. This allows for establishing an in situ intensity diagnostic by measuring the positron current in experiments where peta-watt class lasers are used.
关键词： high power lasers,QED in plasmas,laser intensity diagnostics
更新于2025-09-23 15:21:01