Showing papers on "Solenoid published in 2020"
TL;DR: The CORC® cable insert solenoid was successfully tested in liquid helium in background magnetic fields of up to 14 T, resulting in a combined central magnetic field of 15.86 T and a peak magnetic field on the conductor of 16.77 T at a critical current of 4,404 A, a winding current density of 169 A/mm2, an engineering currentdensity of 282 A/MM2, and a JBr source stress of 275 MPa as mentioned in this paper.
Abstract: The results presented in this Letter describe the successful test of the first high-temperature superconducting multi-tesla insert solenoid tested at currents exceeding 4 kA while operating in a background magnetic field of a low-temperature superconducting outsert magnet. A 45-turn insert solenoid, wound from 19 meters of CORC® cable, was designed to operate at high current, high current density, and high hoop stress in high magnetic background field; a combination that is essential in the development of low-inductance, high-field magnets. The CORC® cable insert solenoid was successfully tested in liquid helium in background magnetic fields of up to 14 T, resulting in a combined central magnetic field of 15.86 T and a peak magnetic field on the conductor of 16.77 T at a critical current of 4,404 A, a winding current density of 169 A/mm2, an engineering current density of 282 A/mm2, and a JBr source stress of 275 MPa. Stable operation of the CORC® cable insert magnet in its superconducting transition was demonstrated, during charging at rates of 20 – 50 A/s, without inducing a quench. The results are a clear demonstration of the major benefits of this multi-tape CORC® magnet conductor in which current sharing between tapes is possible, thereby removing some of the stringent conductor requirements of single-tape magnets. The CORC® cable insert solenoid demonstrated operation at about 86 % of the expected CORC® cable performance and showed no significant degradation after 16 high-current test cycles in background fields ranging from 10 to 14 T. CORC® cables have matured into practical and reliable high-field magnet conductors, achieving important high current, high current density, stress tolerance, and quench protection milestones for high field magnet technology. They have established a straightforward path towards low-inductance magnets that operate at magnetic fields exceeding 20 T.
37 citations
TL;DR: It is shown that the AB phase is mediated locally by the entanglement between the charge and the photons, like all electromagnetic phases, and predicted a gauge-invariant value for the phase difference at each point along the charge's path.
Abstract: In the Aharonov-Bohm (AB) effect, a superposed charge acquires a detectable phase by enclosing an infinite solenoid, in a region where the solenoid's electric and magnetic fields are zero. Its generation seems therefore explainable only by the local action of gauge-dependent potentials, not of gauge-independent fields. This was recently challenged by Vaidman, who explained the phase by the solenoid's current interacting with the electron's field (at the solenoid). Still, his model has a residual nonlocality: it does not explain how the phase, generated at the solenoid, is detectable on the charge. In this Letter, we solve this nonlocality explicitly by quantizing the field. We show that the AB phase is mediated locally by the entanglement between the charge and the photons, like all electromagnetic phases. We also predict a gauge-invariant value for the phase difference at each point along the charge's path. We propose a realistic experiment to measure this phase difference locally, by partial quantum state tomography on the charge, without closing the interference loop.
33 citations
TL;DR: In this paper, the Gaussian process regression (GP regression) method was developed to simulate the central magnetic flux density in a Gaussian manifold with finite element methods that require a significant amount of inputs and computation resources.
Abstract: The central magnetic flux density is usually simulated via finite element methods that require a significant amount of inputs and computation resources. We develop the Gaussian process regression (...
28 citations
TL;DR: The derivation method on the coil impedance increment and inductive voltage and the signal processing method can be extended to design sensors measuring more complicated wear debris.
Abstract: The detection technology on wear debris in lubricating oil is critical to ensure the safe operation of the engines in the aerospace industry. In this article, a triple-coil reverse double-excitation solenoid sensor is discussed. Inside the sensor, electromagnetic field generated by two excitation coils is sensitive to the occurrence of wear debris, and its changes can be captured by the induction coil. Thus, the impedance and inductive voltage of the induction coil can be used to detect the wear debris. Assuming the debris is spherical, an electromagnetic model is established. Via time-harmonic electromagnetic field analysis method, the expressions of the induction coil’s impedance increment and inductive voltage are derived. The relationships between the impedance increment and the parameters of the debris and the coils are investigated. The theoretical results are validated by Maxwell from Ansys, Canonsburg, PA, USA, simulations and experiments. In order to get an accurate voltage output signal, a passband filter amplifier is designed to connect to the output of the induction coil and empirical mode decomposition is presented to process the digital voltage signal. The derivation method on the coil impedance increment and inductive voltage and the signal processing method can be extended to design sensors measuring more complicated wear debris.
26 citations
TL;DR: In this article, the authors explore the dependency of harmonic ac losses of different coil configurations carrying nonsinusoidal current, and they find that AC loss in coils monotonically increases with the increase of the fifth harmonic, drastically.
Abstract: Application of high-temperature superconducting devices become promising in power networks, and transportation, including ship, train, and electric aircraft propulsion systems, with the advantages of light weight, compact size, and high efficiency, compared to conventional devices. In reality, electric networks—either in grid or transportation propulsion system—are polluted with harmonics due to the widespread use of power electronic devices and nonlinear loads. It is essential to explore the dependency of harmonic ac losses of different coil configurations carrying nonsinusoidal current. We modeled and compared harmonic ac loss behaviors in three coil configurations, single pancake coil (SPC), double pancake coil (DPC), and solenoid coil (SNC), where SPC and SNC are wound by identical wire length and DPC has twice conductor number compared to SPC. The research work has been carried out by means of H-formulation finite element method in a 2-D axisymmetric modeling environment of COMSOL Multiphysics. We explored and reported ac losses in these three coil structures carrying nonsinusoidal current with the third and the fifth harmonic orders, respectively, under different total harmonic distortion (THD) and fundamental current levels. It has been concluded that ac loss in these coils first decreases with the increase of the third harmonic content, when THD of the third harmonic 0.2. AC loss in coils monotonically increases with the increase of the fifth harmonic, drastically. We found that ac loss in SPC carrying the third harmonic and the fifth harmonic at different THD are more than 3.8 times of that in DPC; ac loss in SPC carrying either third or fifth harmonics at different THD are around 4.5 times of that in SNC.
25 citations
TL;DR: In this article, a hybrid central solenoid is proposed based on ten layer-wound sub-coils using HTS, Nb3Sn and Nb-Ti conductors respectively for the high, medium, and low field sections.
Abstract: State-of-the-art high field solenoids make use of hybrid designs exploiting the superior high field performance of High Temperature Superconductors (HTS) in the innermost region. The benefits of a hybrid Central Solenoid in a pulsed tokamak like the EU DEMO can be two-fold: either to reduce its outer radius (which would result in a reduced overall size and cost of the tokamak), or to increase the generated magnetic flux (which could extend the plasma burn time and possibly increase the power plant efficiency). In the framework of the pre-conceptual design studies for DEMO coordinated by EUROfusion, a hybrid Central Solenoid is proposed based on ten layer-wound sub-coils using HTS, Nb3Sn, and Nb-Ti conductors respectively for the high, medium, and low field sections. The design exploits the flexibility of layer winding by grading both the superconductor and the stainless steel cross sections in each sub-coil, which has the potential for space and cost savings. Mechanical analyses have identified fatigue as the main design driver for the EU DEMO Central Solenoid. Possible alternatives to reduce the sensitivity of the proposed design to fatigue are currently under investigation.
25 citations
22 citations
Posted Content•
TL;DR: In this paper, the authors present a view on EM space flight and Fermion Crushing based on kitchen table experiments and my Q-FFF Rigid Transformer String Theory.
Abstract: The electromagnetic field around a direct current in a wire and the so called Lorentz force, has always been questioned by me and others about the microscopic visualization of individual (string) particle physics. (figure 1). Now I present my view on EM space flight and Fermion Crushing based on kitchen table experiments and my Q-FFF Rigid Transformer String Theory. Also for Fermion crushing by focused B-fields at the end of solenoids we can use direct- or alternative currents, due to both opposite interference field symmetries at the end of the two coaxial solenoids. 1, for a two Coaxial Solenoid, (figure 2,3,4,5), 2, for a two equal diameter conductor Coaxial Tesla Pancake Coil with one lager tubular conductor pancake coil in the middle (Trifilar coil) for reaction less propulsion(figure 6, 30, 31)
20 citations
TL;DR: In this article, a multilayer 2D axisymmetric coil model based on H-formulation is proposed and validated by experimental results as the HTS film layer is inapplicable at such frequencies.
Abstract: Wireless power transfer (WPT) is an emerging technology with widespread applications, such as wireless charging for electric vehicles (EVs), which has become a major point of interest. Conventionally, it is used for stationary charging, but also dynamic systems emerge. Key drawbacks of standard WPT systems are the limited transfer distance between the copper coils and the transfer efficiency. By employing high-temperature superconductors (HTS) as coil material these limitations can be alleviated. However, HTS coils have highly nonlinear ac loss characteristics, which will be studied. This paper investigates the transport current loss and the magnetisation loss of HTS coils individually and when combined in the high frequency range relevant to WPT for EVs. A multilayer 2D axisymmetric coil model based on H-formulation is proposed and validated by experimental results as the HTS film layer is inapplicable at such frequencies. Three of the most commonly employed coil configurations, namely: double pancake, solenoid and circular spiral are examined. While spiral coils experience the highest transport current loss, solenoid coils are subject to the highest magnetisation loss due to the overall distribution of the turns. Furthermore, a transition frequency is defined for each coil when losses in the copper layer exceed the HTS losses. It is much lower for coils due to the interactions between the different turns compared to single HTS tapes. At higher frequencies, the range of magnetic field densities, causing a shift where the highest losses occur, decreases until losses in the copper stabilisers always dominate. In addition, case studies investigating the suitability of HTS-WPT are proposed.
19 citations
TL;DR: This paper presents the fabrication and characterization of a flexible, flat, miniaturized fluxgate sensor with a thin amorphous rectangular magnetic core fabricated by the pad/printing technique, which is the first to be printed with a conventional micro-printeding technique.
Abstract: This paper presents the fabrication and characterization of a flexible, flat, miniaturized fluxgate sensor with a thin amorphous rectangular magnetic core fabricated by the pad/printing technique. Both the design and the various printing steps of the sensor are presented. The fluxgate sensor comprises of solenoid coils, and to the best of our knowledge, is the first to be printed with a conventional micro-printing technique. The magnetic core is a non-printed component, placed between the printed layers. The sensor's linear measuring range is ±40 µT with 2% full-scale linearity error, at 100 kHz excitation frequency. The highest measured sensitivity reaches 14,620 V/T at 200 kHz, while the noise of the sensor was found to be 10 nT/ Hz at 1 Hz.
17 citations
TL;DR: In this paper, a superconducting solenoid for muon and pion capture at the China Spallation Neutron Source (CSNS) is proposed, which is composed of four windings and an iron yoke for flux returning and magnetic field shielding.
Abstract: The experimental muon source (EMuS) project foreseen for muon science and neutrino physics is utilizing a superconducting solenoid for muon and pion capture, and is proposed at the China Spallation Neutron Source (CSNS). For the optimal particles collection efficiencies, an adiabatic magnetic field from 5 to 2.2 T along the central axis of the solenoid is generated by the solenoid. The superconducting solenoid is composed of four windings and an iron yoke. The iron yoke is arranged for flux returning and magnetic field shielding. Two conductor options for the windings, the aluminum stabilized NbTi Rutherford cable and the NbTi monolith wire are compared from the mechanical structure and radiation performance. The results of the mechanical analysis from ANSYS show that the excitation stress is suitable. But the results of the radiation analysis from FLUKA Monte-Carlo show that the recovery of the Residual Resistivity Ratios (RRRs) is necessary for the stabilizers of the superconductor. The recovery cycle of the aluminum stabilizer and the monolith wire solenoids are three months and one year, respectively. However, the RRR of copper for the monolith wire solenoid will be less than 50, after 12 years continuous running, which is shorter than the EMuS lifetime of 30 years. Therefore, the aluminum stabilized NbTi Rutherford cables are chosen to fabricate the windings.
TL;DR: In this paper, an advanced commutation technology composed of a mechanical bypass switch, vacuum circuit breaker, and LC commutation circuit based on artificial current zero technology has been worked out to meet the current and voltage requirement (10 kV/100 kA).
Abstract: China fusion engineering test reactor is a new tokamak device, which is one design option under the consideration of the China National Integration Design Group employs superconducting magnets. The main target of this project is to build a self-sufficient fusion engineering tokamak reactor with its fusion power 50-200 MW. Toroidal field coils, center solenoid coils, and poloidal field (PF) coils, whose rated current range from 52.9 to 90 kA, produce the magnetic field for plasma generation and confinement. The core of quench protection unit is to divert the coil current into discharge resistor by using commutation technology, which should be determined by the rated current and voltage requirement of magnets. Different kinds of technologies for quench protection unit (QPU) are considered, and an advanced commutation technology composed of a mechanical bypass switch, vacuum circuit breaker (VCB), and LC commutation circuit based on artificial current zero technology has been worked out to meet the current and voltage requirement (10 kV/100 kA). To provide a faster and more reliable removal of the energy stored in those superconducting coils, this paper analyzes in detail the feasibility of a commutation scheme based on artificial current zero technology by analyzing and simulating each stage of the commutation process at such large rated current and voltage conditions. Both analysis and simulation results verified that the operating reliability of QPU can be guaranteed by this 100 kA dc commutation scheme.
TL;DR: Results show that the model-based detection method is able to detect the early signs of coil failure, and robust behavior and high detection probabilities are achieved for realistic fault sizes.
Abstract: This article describes the development and application of a model-based scheme for detecting the early signs of coil failure in solenoid valves. Contrary to other works, the proposed method simply isolates the fault-induced change in the coil resistance from thermal effects and provides a cost-effective solution with no comprehensive equipment demand. The model-based detection method employs a simple thermal model of the solenoid and an extended Kalman filter (EKF) for generating coil current residuals. The EKF utilizes measurements of coil voltage, coil current, ambient, and fluid temperature. The CUmulative SUM of the current residual is found to be sensitive to the early signs of coil failure. An experimental setup is utilized for evaluating the robustness of the detection method in the event of changing ambient temperature, convection, and fluid flow conditions. Results show that the method is able to detect the early signs of coil failure, and robust behavior and high detection probabilities are achieved for realistic fault sizes. The realistic fault sizes and the number of fault instances before failure are determined through extensive accelerated tests, where solenoids are operated at high temperature until failure.
15 Mar 2020
TL;DR: In this article, the authors reported the design, fabrication and characterization of on-chip solenoid inductors with novel magnetic thin-film core for high frequency DC-DC power conversion application.
Abstract: In this paper, we are reporting the design, fabrication and characterization of on-chip solenoid inductors with novel magnetic thin-film core for high frequency DC-DC power conversion application Our CMOS - BEOL process compatible micro-inductor fabricated shows a high L/Rdc up to 440 nH/Q due to a thick Cu winding, as well as a high inductance density of 440 nH/mm2 and high Q factor of 145 at 10 MHz which results from inclusion of laminated Co-based magnetic core which is amorphous and shows very good soft magnetic properties The on-chip magnetic-film inductor technology is targeted at applications that enable high frequency (>10 MHz) DC-DC power conversion
TL;DR: A novel hybrid hydraulic system which includes a unidirectional servo valve and a solenoid on-off valve is excogitated, and its energy saving control is studied in this paper.
Abstract: For the purpose of reducing power consumption of a leg exoskeleton for augmenting human performance, a novel hybrid hydraulic system (HHS) which includes a unidirectional servo valve and a solenoid on-off valve is excogitated, and its energy saving control is studied in this paper. Inspired by the varieties of contact force between human leg and ground during walking, the unidirectional servo valve and the solenoid on-off valve are only activated in the stance phase and the swing phase, respectively. In the stance phase, a robust repetitive learning scheme is presented by using the backstepping technique for the unidirectional servo valve, aiming to track the periodic human leg movement, and in the swing phase, an on-off control is proposed for the solenoid valve to release the pressure in the hydraulic cylinder so that the exoskeleton leg is bent by the human leg passively. The proposed control strategy is implemented in an ARM-based embedded microprocessor and the control performance is verified via experiment on the developed exoskeleton robot. The experimental results show that the power consumption of the proposed system is almost 30% less than that of systems with bidirectional hydraulic system.
11 May 2020-Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment
TL;DR: In this paper, the authors describe the design, construction, installation, commissioning, and operation of two superconducting iron-free magnets, a torus and a solenoid.
Abstract: As part of the Jefferson Lab 12 GeV upgrade, the Hall B CLAS12 system requires two superconducting iron-free magnets — a torus and a solenoid. The physics requirements to maximize space for the detectors guided engineers toward particular coil designs for each of the magnets which, in turn, led to the choice of using conduction cooling. The torus consists of 6 trapezoidal NbTi coils connected in series with an operating current of 3770 A. The solenoid is an actively shielded 5 T magnet consisting of 5 NbTi coils connected in series operating at 2416 A. Within the hall, the two magnets are located in close proximity to each other and are completely covered both inside and outside by particle detectors. Stringent size limitations were imposed for both magnets and introduced particular design and fabrication challenges. This paper describes the design, construction, installation, commissioning, and operation of the two magnets.
TL;DR: In this paper, the state-of-the-art Common rail solenoid and direct acting piezoelectric injectors have been tested at a dynamometer cell.
TL;DR: In this article, a straight core solenoid was designed to develop a new demagnetization furnace with ultra-low magnetic field noise, which can yield low noise results even for weakly magnetic samples.
Abstract: Thermal demagnetization furnaces are widely used paleomagnetic facilities for progressive removal of naturally acquired magnetic remanence or the imparting of well-controlled laboratory magnetization. An ideal thermal demagnetizer should maintain “zero” magnetic field in the sample chamber during thermal treatments. However, magnetic field noises, including the residual magnetic fields of the construction material and the induced fields caused by the alternating current (AC) in the heating element are always present, which can contaminate the paleomagnetic results at the elevated temperatures or especially for the magnetically weak samples. Here, we designed a new structure of heating wire named “straight core solenoid” to develop a new demagnetization furnace with ultra-low magnetic field noise. Simulation and practical measurements show that the heating current magnetic field can be greatly reduced by using the new technology. Thermal demagnetization experiments demonstrate that the new demagnetizer can yield low noise results even for weakly magnetic samples.
TL;DR: A summary of closed-form expressions for the magnetic fields produced by rectangular-and circular-shaped finite-length solenoids and current loops is provided in this paper for easy reference.
Abstract: A summary of closed-form expressions for the magnetic fields produced by rectangular- and circular-shaped finite-length solenoids and current loops is provided altogether for easy reference. Each expression provides the magnetic field in all space, except locations where a current of infinitesimal thickness is considered to exist. The closed-form expression for the magnetic field of a rectangular-shaped finite-length solenoid is derived using the Biot–Savart law. Closed-form expressions for the magnetic fields of solenoids and current loops can be used to avoid approximations in analytical models and may reduce computation time in computer simulations.
TL;DR: In this article, the design, modeling, fabrication, and characterization of a system-in-package (SiP) power inductor using a NiZn ferrite composite magnetic core material is demonstrated.
Abstract: In this paper, the design, modeling, fabrication, and characterization of System-in-Package (SiP) solenoid power inductor using a NiZn ferrite composite magnetic core material is demonstrated. A novel fabrication process has been developed for integrating the inductor into the buck-type integrated voltage regulator (IVR) module. The process uses stencil printing to deposit and pattern the magnetic core material. Photolithography and copper electroplating are used to form the windings. The electrical parameters of the fabricated inductors were extracted from measurements. The inductors had an average dc resistance of 19 $\text{m}\Omega $ , average inductance of 28.3 nH, and average ac resistance of $2.28~\Omega $ at 100 MHz, which is the operating frequency of the IVR. The organic substrate parasitic effect led to an average shunt capacitance of 2.31 pF and an average parasitic conductance of 0.12 mS at 100 MHz. The 10% saturation current was 11.53 A. The electrical parameters of the fabricated inductors were modeled and showed good accuracy with measured data. The inductors showed an inductance to dc resistance ratio of 1613 nH/ $\Omega $ . The area and volume energy densities were 158.4 nJ/mm2 and 283.0 nJ/mm3, respectively. These are the highest reported values for a solenoid magnetic core power inductor at 100 MHz.
TL;DR: In this paper, the authors formulate the Busch theorem in quantum mechanical form and discuss the generation of quantized vortex beams, i.e., beams carrying a quantized orbital angular momentum.
Abstract: Due to the conservation of the canonical angular momentum, charged particle beams which are generated inside a solenoid field acquire a kinetic angular momentum outside of the solenoid field. The relation of kinetic orbital angular momentum to the field strength and the beam size on the cathode is called the Busch theorem. We formulate the Busch theorem in quantum mechanical form and discuss the generation of quantized vortex beams, i.e., beams carrying a quantized orbital angular momentum. Immersing a cathode in a solenoid field presents an efficient and flexible method for the generation of electron vortex beams, while, e.g., vortex ions can be generated by immersing a charge stripping foil in a solenoid field. Both techniques are utilized at accelerators for the production of nonquantized vortex beams. As a highly relevant use case we discuss in detail the conditions for the generation of quantized vortex beams from an immersed cathode in an electron microscope. General possibilities of this technique for the production of vortex beams of other charged particles are pointed out.
TL;DR: A model is described that accurately predicts the deflection of an electron beam trajectory in the vicinity of the fringing field of a solenoid and is shown to be more accurate than the other models relative to the experimental results obtained.
Abstract: Computer modelling is widely used in the design of scientific instrumentation for manipulating charged particles, for instance: to evaluate the behaviour of proposed designs, to determine the effects of manufacturing imperfections and to optimise the performance of apparatus. For solenoids, to predict charged particle trajectories, accurate values for the magnetic field through which charged species traverse are required, particularly at the end regions where fringe fields are most prevalent. In this paper, we describe a model that accurately predicts the deflection of an electron beam trajectory in the vicinity of the fringing field of a solenoid. The approach produces accurate beam deflection predictions in the fringe field region as well as in the centre of the solenoid. The model is based on a direct-line-of-action force between charges and is compared against field-based approaches including a commercially available package, with experimental verification (for three distinct cases). The direct-action model is shown to be more accurate than the other models relative to the experimental results obtained.
ENEA1
TL;DR: The Divertor Tokamak Test facility (DTT) is a project of an experimental tokamak reactor developed in Italy, in the framework of the European Fusion Roadmap as discussed by the authors.
Abstract: The Divertor Tokamak Test facility (DTT) is a project of an experimental tokamak reactor developed in Italy, in the framework of the European Fusion Roadmap. This work presents the magnetic and the structural assessment of the performance of the DTT central solenoid. The CS is the core magnet of the poloidal system and generates the magnetic flux needed to induce the plasma current. This magnet is composed of a stack of six layer-wound independently energized modules, comprised of Nb3Sn Cable-in-Conduit Conductors. To optimize the amount of superconductive material, each module is divided into two submodules. The inner- most submodule operates in a range of about 8/13.5 T, while the outer one at 6/8.5 T. The objective of the design process is to obtain a coil that is capable of providing the required magnetic performance while being structurally compliant. To address this problem, an analytical assessment has been carried out and a thoroughly parametric Finite Element Model (FEM) has been implemented.
TL;DR: In this paper, a relativistic spin-half particle in the background of a long-thin magnetic-flux-carried solenoid was investigated and it was shown that, up to the first order of the noncommutative parameter, there are no non-commutable corrections on the AB effects for both cases.
11 May 2020-Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment
TL;DR: The Central Drift Chamber as discussed by the authors is a straw-tube wire chamber of cylindrical structure located surrounding the target inside the bore of the GlueX spectrometer solenoid, whose purpose is to detect and track charged particles with momenta as low as 0.25 ǫ/c and to identify low-momentum protons via energy loss.
Abstract: The Central Drift Chamber is a straw-tube wire chamber of cylindrical structure located surrounding the target inside the bore of the GlueX spectrometer solenoid. Its purpose is to detect and track charged particles with momenta as low as 0.25 GeV/c and to identify low-momentum protons via energy loss. The construction of the detector is described and its operation and calibration are discussed in detail. The design goal of 150 μ m in position resolution has been reached.
TL;DR: A wind-and-react MgB2 solenoid magnet for klystrons has been developed in this paper, which consumes less than 3kW in refrigerator power.
Abstract: A wind-and-react MgB2 solenoid magnet for klystrons has been developed. While the current normal-conducting (Cu) magnet consumes 20 kW per magnet, this MgB2 magnet consumes less than 3 kW in refrigerator power. The conduction-cooled half coil of the magnet is 337 mm in inner diameter; the winding pack, 19.4 mm wide × 136.6 mm high, uses 2.7 km of 10 filament circular conductor, which is insulated with glass 0.83 mm in diameter, and is reacted after being wound onto a stainless steel bobbin. The coil has Cu plates of 0.2 mm in thickness between each coil layer and on the inner and outer sides. The magnet has two coils and produces 0.8 T in the center and its stored energy is 11.8 kJ. Together with the above-mentioned coil structure, these coils can consume stored energy in itself at quench without a special quench protection system. A performance test of the magnet was successful.
TL;DR: A high speed, high pressure solenoid actuated valve has been developed for use as a driver section for automated shock tubes and retains the performance of prior versions of the valve and creates very reproducible reaction conditions in the shock tube.
Abstract: A high speed, high pressure solenoid actuated valve has been developed for use as a driver section for automated shock tubes. The valve is based on a prior design, and significant improvements in the design of the valve are described. The new design retains the performance of prior versions of the valve and creates very reproducible reaction conditions in the shock tube, which are illustrated by several thousand experiments. In addition, the longevity of the valve is improved, failures are reduced, and the maintenance and manufacture of the valve are simplified.
TL;DR: In this article, it was shown that the stable-algebra is the stationary inductive limit of a stable Fell algebra that has a compact spectrum and trivial Dixmier-Douady invariance.
Abstract: Wieler has shown that every irreducible Smale space with totally disconnected stable sets is a solenoid (i.e., obtained via a stationary inverse limit construction). Using her construction, we show that the associated stable -algebra is the stationary inductive limit of a -stable Fell algebra that has a compact spectrum and trivial Dixmier–Douady invariant. This result applies in particular to Williams solenoids along with other examples. Beyond the structural implications of this inductive limit, one can use this result to, in principle, compute the -theory of the stable -algebra. A specific one-dimensional Smale space (the -solenoid) is considered as an illustrative running example throughout.
TL;DR: It is anticipated that the proposed fault detection method can be widely applicable to diagnose any electromagnetic actuator of engineered systems as well as solenoid valves in various industrial applications.
Abstract: Solenoid valves are widely used to control fluid flow in various mechanical systems. If the valves do not function properly, the mechanical systems can lose their ability to control the fluid flow. This paper describes a fault detection method that can monitor coil burnout under dynamic thermal loading. The method consists of three steps. First, an equivalent current model of the solenoid valves is derived from Kirchhoff's voltage law. Then, a predictive regression model is developed to describe the relationship between the electric current and the dynamic change of operating temperature of the valves. Finally, a health indicator of solenoid coil burnout is devised in conjunction with the derived model. To demonstrate the validity of the proposed fault detection method, a case study is presented with solenoid valves taken from real braking systems of urban railway vehicles. The case study confirms that the proposed method can detect the coil burnout independent of the operating temperature. We anticipate that the proposed method can be widely applicable to diagnose any electromagnetic actuator of engineered systems as well as solenoid valves in various industrial applications.
TL;DR: A DC current sensor based on an optically pumped atomic magnetometer is proposed in this paper, which exhibits a high accuracy with a non-moment solenoid and magnetic shielding to suppress the influence from the environment.
Abstract: A DC current sensor based on an optically pumped atomic magnetometer is proposed. It has a high linearity in a wide operation range, since the magnetometer measures the absolute magnitude of the magnetic field produced by the current to be measured. The current sensor exhibits a high accuracy with a non-moment solenoid and magnetic shielding to suppress the influence from the environment. The absolute error of the measured current is below 0.08 mA when the range is from 7.5 mA to 750 mA. The relative error is 5.54 × 10−5 at 750 mA.