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Results for “ELECTRIC COILS”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 19 records

Study of the Heater-Coil Electrical Insulation for the HL-LHC Low Beta Quadrupoles

In the framework of the HL-LHC project, the present LHC low-β superconducting quadrupoles will be substituted with higher performance Nb 3 Sn magnets (MQXF) with 11.4 T coil peak field. MQXF coils are impregnated with epoxy resin to reduce risk of stress concentration on the brittle conductor. The magnet quench protection is provided by CLIQ and quench heaters to ensure a redundant system. Quench heaters are impregnated with the coils in order to have suitable thermal contact with them, and to prevent the hot spot temperature from exceeding 350K during normal operation in case of a quench. Quench heaters are insulated from the coil by S-2 Glass and polyimide. Here, the test of the first MQXF prototype (4 m long) MQXFAP1 was stopped by a coil-to-ground short circuit triggered by a heater-to-coil short. This issue triggered a root analysis of the causes of this short. Here we prove that the use of a non-conforming cloth in coil impregnation, further weakened by non-conforming high voltage test, has triggered the shorts. Moreover, we present an analysis of the heater-to-coil insulation strength, showing the role of blistering phenomena and how they are triggered by a combination of magnet powering and heater firing.

43 PARTICLE ACCELERATORS↗

Using fiberglass volumes for VPI of superconductive magnetic systems’ insulation

The paper describes the method of manufacturing fiberglass molds for vacuum pressure impregnation (VPI) of high-voltage insulation of superconductive magnetic systems (SMS) with epoxidian hot-setting compounds. The basic advantages of using such vacuum volumes are improved quality of insulation impregnation in complex-shaped areas, and considerable cost-saving of preparing VPI of large-sized components due to dispensing with the stage of fabricating a metal impregnating volume. Such fiberglass vacuum molds were used for VPI of high-voltage insulation samples of an ITER reactor’s PF1 poloidal coil. Electric insulation of these samples has successfully undergone a wide range of high-voltage and mechanical tests at room and cryogenic temperatures. Some results of the tests are also given in this paper.

36 MATERIALS SCIENCE↗

Multi-phase Wireless Power Transfer with High Power Density Inductive Coils for Electric Drone Charging

Wireless charging of unmanned ground vehi-cles and aircraft has been proposed to increase charging reliability and security, allow for autonomous functionality, and either reduce battery size or increase continuous flight time. This paper proposes a three-phase Litz wire primary and a two-phase PCB secondary for high secondary-side power density considering misalignment tolerances, surface and volumetric power density, and coil sizing. Elec-tromagnetic 3D finite element analysis (FEA) simulations are conducted to study variation in mutual inductance and coupling coefficient with different secondary coil sizes and number of turns, horizontal and vertical misalignment between the primary and secondary, and a combination of both for a set of designs with the same rated power. Results indicate that receiver coils of reduced size relative to the primary can deliver rated power for increased power density and higher tolerance to misalignment.

Gastineau, Lucas [University of Kentucky]↗

Wet Winding Improves Coil Encapsulation

Wet-winding process encapsulates electrical coils more uniformily than conventional processes. Process requires no vacuum pump and adapts easily to existing winding machines. Encapsulant applied to each layer of wire as soon as added to coil. Wet-winding process eliminates voids, giving more uniformly encapsulated coil.

Hill, A. J.↗

Magnetically Damped Furnace Bitter Magnet Coil 1

A magnet has been built by the National High Magnetic Field Laboratory for NASA on a cost reimbursement contract. The magnet is intended to demonstrate the technology and feasibility of building a magnet for space based crystal growth. A Bitter magnet (named after Francis Bitter, its inventor) was built consisting of four split coils electrically in series and hydraulically in parallel. The coils are housed in a steel vessel to reduce the fringe field and provide some on-axis field enhancement. The steel was nickel plated and Teflon coated to minimize interaction with the water cooling system. The magnet provides 0.14 T in a 184 mm bore with 3 kW of power.

Bird, M. D.↗

Irradiation imposed degradation of the mechanical and electrical properties of electrical insulation for future accelerator magnets

Future accelerators will make extensive use of superconductors made of Nb{sub 3}Sn, which allows higher magnetic fields than NbTi. However, the wind-and-react technology of Nb{sub 3}Sn superconducting magnet production makes polyimide Kapton® non applicable for the coils' electrical insulation. A Nb{sub 3}Sn technology compatible insulation material should be characterized by high radiation resistivity, good thermal conductivity, and excellent mechanical properties. Candidate materials for the electrical insulation of future accelerator's magnet coils have to be radiation certified with respect to potential degradation of their electrical, thermal, and mechanical properties. This contribution presents procedures and results of tests of the electrical and mechanical properties of DGEBA epoxy + D400 hardener, which is one of the candidates for the electrical insulation of future magnets. Two test sample types have been used to determine the material degradation due to irradiation: a untreated one (unirradiated) and irradiated at 77 K with 11 kGy/min intense, 4MeV energy electrons beam to a total dose of 50 MGy.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗

External split field generator

A generator includes a coil disposed about a core. A first stationary magnetic field source may be disposed on a first end portion of the core and a second stationary magnetic field source may be disposed on a second end portion of core. The first and second stationary magnetic field sources apply a stationary magnetic field to the coil. An external magnetic field source may be disposed outside the coil to apply a moving magnetic field to the coil. Electrical energy is generated in response to an interaction between the coil, the moving magnetic field, and the stationary magnetic field.

30 DIRECT ENERGY CONVERSION↗

Designing Dynamic Wireless Power Transfer Corridors for Heavy Duty Battery Electric Commercial Freight Vehicles

The use of wireless power transfer systems, consisting of inductive electrical coils on the vehicle and the power source may be designed for dynamic operations where the vehicle will absorb energy at highway speeds from transmitting coils in the road. This has the potential to reduce the onboard energy storage requirements for vehicles while enabling significantly longer missions. This paper presents an approach to architecting a dynamic wireless power transfer corridor for heavy duty battery electric commercial freight vehicles. By considering the interplay of roadway power capacity, roadway and vehicle coil coverage, seasonal road traffic loading, freight vehicle class and weight, vehicle mobility energy requirements, on-board battery chemistry, non-electrified roadway vehicle range requirements, grid capacity, substation locations, and variations in electricity costs, we minimize the vehicle TCO by architecting the electrified roadway and the vehicle battery simultaneously. The idea optimizes battery size and chemistry so that the depth of discharge between recharge events and expected life are balanced, thus fully utilizing the energy available throughout the course of the battery system's life. The approach is illustrated by applying it to the I-75 freight corridor, where the framework developed may be expanded and applied to a larger interstate system, expanded regional corridor, or other transportation network.

Sujan, Vivek↗

Characteristics of anomalous skin effect and evolution of power absorption regions in a cylindrical radio frequency inductively coupled plasma

In a low-pressure radio-frequency (13.56 MHz), inductively coupled argon plasma generated by a normal cylindrical rf coil, electric field, current density, and absorbed power density is calculated from magnetic field measured with a phase-resolved magnetic probe. The anomalous skin effect (ASE) for the cylindrical rf coil is compared to those previously reported for the planar and re-entrant cylindrical rf coils. Physical reasons for our observed characteristics of ASE are presented. With the increasing discharge power, the size and the number of negative and positive power absorption regions evolve into several distinct patterns. For the low discharge power (at 156.9 W), there is one area of positive and one area of negative power absorption in the radial direction. For the medium discharge power (279 W–683.5 W), there are two areas of negative and two areas of positive power absorption. For the even higher discharge power (above 803.5 W), the number of areas is the same as that of the medium discharge power, but the size of the inner positive and negative power absorption areas is approximately doubled and halved, respectively, while the outer positive and negative power absorption areas slightly shrinks. The evolution of positive and negative power absorption regions is explained as a result of electron thermal diffusion and the energy conversion between rf current and electric field. The spatial decays of electric field and current density are also elucidated by linking them with the positive and negative power absorption pattern.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗

Remote lightning monitor system

An apparatus for monitoring, analyzing and accurately determining the value of peak current, the peak rate of change in current with respect to time and the rise time of the electrical currents generated in an electrical conductive mast that is located in the vicinity where lightning is to be monitored is described. The apparatus includes an electrical coil for sensing the change in current flowing through the mast and generating a voltage responsive. An on-site recorder and a recorder control system records the voltages produced responsive to lightning strikes and converts the voltage to digital signals for being transmitted back to the remote command station responsive to command signals. The recorder and the recorder control system are carried within an RFI proof environmental housing into which the command signals are fed by means of a fiber optic cable so as to minimize electrical interference.

Lennon, C. L.↗

Gas and Propane Combustion from Stoves Emits Benzene and Increases Indoor Air Pollution

Exposure pathways to the carcinogen benzene are well-established from tobacco smoke, oil and gas development, refining, gasoline pumping, and gasoline and diesel combustion. Combustion has also been linked to the formation of nitrogen dioxide, carbon monoxide, and formaldehyde indoors from gas stoves. To our knowledge, however, no research has quantified the formation of benzene indoors from gas combustion by stoves. Across 87 homes in California and Colorado, natural gas and propane combustion emitted detectable and repeatable levels of benzene that in some homes raised indoor benzene concentrations above well-established health benchmarks. Mean benzene emissions from gas and propane burners on high and ovens set to 350 °F ranged from 2.8 to 6.5 μg min –1 , 10 to 25 times higher than emissions from electric coil and radiant alternatives; neither induction stoves nor the food being cooked emitted detectable benzene. Benzene produced by gas and propane stoves also migrated throughout homes, in some cases elevating bedroom benzene concentrations above chronic health benchmarks for hours after the stove was turned off. Combustion of gas and propane from stoves may be a substantial benzene exposure pathway and can reduce indoor air quality.

54 ENVIRONMENTAL SCIENCES↗

Numerical investigation of closed-loop control for Hall accelerators

Low frequency discharge current oscillations in Hall accelerators are conventionally damped with external inductor-capacitor (LC) or resistor-inductor-capacitor (RLC) networks. The role of such network in the stabilization of the plasma discharge is investigated with a numerical model and the potential advantages of proportional-integral-derivative (PID) closed-loop control over RLC networks are subsequently assessed using either discharge voltage or magnetic field modulation. Simulations confirm the reduction of current oscillations in the presence of a RLC network, but suggest that PID control could ensure nearly oscillation-free operation with little sensitivity toward the PID settings.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗

CMS: First Results

A summary of the LHC and CMS detector performance is given and the first CMS results are presented. In particular, emphasis will be given to low-p{sub t} QCD Physics including charged hadron spectra, the measurement of Bose-Einstein (BEC) and angular Correlations, and of underlying event properties.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

Reconstruction and selection of Z{yields}{tau}{tau}{yields}{mu}+{tau}-jet+{nu}'s decays at the CMS experiment

At the LHC, tau leptons are expected in final states of many important physics processes including Supersymmetry and the production of Higgs boson(s) and other exotic particles. An efficient and accurate {tau} reconstruction and identification are therefore an important part of the CMS physics programme. Z{sup 0}{yields}{tau}{sup +}{tau}{sup -} decays are often considered the ''standard candle'' of tau reconstruction as they validate tau lepton identification and provide a test bench for Higgs searches (for which they constitute the main irreducible background). We describe techniques for selecting and reconstructing the Z{sup 0}{yields}{tau}{sup {+-}}{tau}{sup {-+}}{yields}{mu}{sup {+-}}{nu}{sub {mu}}{bar {nu}}{sub {tau}}({bar {nu}}{sub {mu}}{nu}{sub {tau}})+{tau}-jet{sup {-+}}{nu}{sub {tau}}({bar {nu}}{sub {tau}}) events that were developed for the measurement of the Z production cross-section by the CMS experiment using 200 pb{sup -1} of the LHC collision data at the center-of-mass energy {radical}(s) 10 TeV. We validate these techniques using simulated events and present a data-driven method for estimating background contributions to this measurement.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

Muons in minimum bias events from the first CMS data

Muon signatures are extremely important in the challenging environment of collisions at the LHC. Understanding the observed muon yield from Standard Model processes is the first task for all analyses involving muons. Basic muon kinematical observables are presented for the first CMS data at {radical}(s) = 7 TeV and compared with Monte Carlo expectations. The muon sample composition is studied by using the MC truth in terms of muons from heavy flavours, muons from light hadron decays and hadron punch-through is studied from MC truth.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

Hadron Physics with KLOE and KLOE-2 Experiments

The KLOE experiment has collected 2.5 fb{sup -1} at the peak of the {phi} resonance at the e{sup +}e{sup -} collider DA{Phi}NE in Frascati and KLOE-2 is expected to start data taking at the upgraded DA{Phi}NE {phi}-factory late 2010, with the aim to collect 25 fb{sup -1} at the {phi} peak and it is under discussion the collection of 5 fb{sup -1} between 1 and 2.5 GeV. KLOE data have been used to investigate the properties of the light scalar mesons f{sub 0}(980), a{sub 0}(980) and light pseudoscalar mesons {eta}, {eta}', using {phi} radiative decays. Gamma-gamma interactions allow to investigate also the f{sub 0}(600)/{sigma} meson, observing the reaction e{sup +}e{sup -} into e{sup +}e{sup -}{pi}{sup 0}{pi}{sup 0}; a direct search of the f{sub 0}(600)/{sigma} into {pi}{sup 0}{pi}{sup 0} decay is performed with data taken at a center of mass of 1 GeV, where {phi} decays are suppressed. We present ongoing analysis and final results already published with the full KLOE statistics and the scientific program of KLOE-2 collaboration on hadron physics.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

Fast electron accumulation and its mechanism in a harmonic trap under ultrahigh vacuum conditions

We present here a fast and efficient electron accumulation in a multiring trap (MRT) in a superconducting solenoid of 5 T. More than 10{sup 10} electrons were accumulated within a fraction of a second for an electron beam in the range of 10{sup -7} A. The MRT was installed in a cryogenic bore tube cooled down to {approx}10 K. Electron accumulation as a function of various parameters such as the beam intensity, the MRT depth, and the MRT length was studied. We succeeded in extracting a consistent picture of the electron accumulation mechanisms, which consist of interactions of the incoming electron beam with the reflected beam and with the electrons trapped in the MRT.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗

A self-consistent global model of solenoidal-type inductively coupled plasma discharges including the effects of radio-frequency bias power

We developed a self-consistent global simulator of solenoidal-type inductively coupled plasma discharges and observed the effect of the radio-frequency (rf) bias power on the plasma density and the electron temperature. We numerically solved a set of spatially averaged fluid equations for charged particles, neutrals, and radicals. Absorbed power by electrons is determined by using an analytic electron heating model including the anomalous skin effect. To analyze the effects of rf bias power on the plasma properties, our model also combines the electron heating and global transport modules with an rf sheath module in a self-consistent manner. The simulation results are compared with numerical results by using the commercial software package cfd-ace + (ESI group) and experimental measurements by using a wave cutoff probe and a single Langmuir probe.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗