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Radio-Frequency Resistance and Inductance of Coils Used in Broadcast Reception

Description: Technical paper issued by the Bureau of Standards over radio-frequency resistance in radio reception. As stated in the introduction, "the purpose of this paper is to present data on the radio-frequency resistance and inductance of coils within the range of frequencies used in radiotelephone broadcasting" (p. 651). This paper includes tables, and illustrations.
Date: October 22, 1925
Creator: Hund, August & De Groot, H. B.
Partner: UNT Libraries Government Documents Department

The Resistance and Strength of Soft Solder Splices between Conductors in MICE Coils

Description: Two of the three types of MICE magnets will have splices within their coils. The MICE coupling coils may have as many as fifteen one-meter long splices within them. Each of the MICE focusing coils may have a couple of 0.25-meter long conductor splices. Equations for the calculation of resistance of soldered lap splices of various types are presented. This paper presents resistance measurements of soldered lap splices of various lengths. Measured splice resistance is shown for one-meter long splices as a function of the fabrication method. Another important consideration is the strength of the splices. The measured breaking stress of splices of various lengths is presented in this paper. Tin-lead solders and tin-silver solders were used for the splices that were tested. From the data given in this report, the authors recommend that the use of lead free solders be avoided for low temperature coils.
Date: August 3, 2010
Creator: Wu, Hong; Pan, Heng; Green, Michael A; Dietderich, Dan; Gartner, T. E.; Higley, Hugh C et al.
Partner: UNT Libraries Government Documents Department

The pulsed linear induction motor concept for high-speed trains

Description: The SERAPBIM (SEgmented RAil PHased Induction Motor) concept is a linear induction motor concept which uses rapidly-pulsed magnetic fields and a segmented reaction rail, as opposed to low-frequency fields and continuous reaction rails found in conventional linear induction motors. These improvements give a high-traction, compact, and efficient linear motor that has potential for advanced high speed rail propulsion. In the SERAPBIM concept, coils on the vehicle push against a segmented aluminum rail, which is mounted on the road bed. Current is pulsed as the coils cross an edge of the segmented rail, inducing surface currents which repel the coil. The coils must be pulsed in synchronization with the movement by reaction rail segments. This is provided by a sense-and-fire circuit that controls the pulsing of the power modulators. Experiments were conducted to demonstrate the feasibility of the pulsed induction motor and to collect data that could be used for scaling calculations. A 14.4 kg aluminum plate was accelerated down a 4 m track to speeds of over 15 m/sec with peak thrust up to 18 kN per coilset. For a trainset capable of 200 mph speed, the SERAPHIM concept design is based on coils which are each capable of producing up to 3.5 kN thrust, and 30 coil pairs are mounted on each power car. Two power cars, one at each end of the train, provide 6 MW from two gas turbine prime power units. The thrust is about 210.000 N and is essentially constant up to 200 km/hr since wheel slippage does not limit thrust as with conventional wheeled propulsion. A key component of the SERAPHIM concept is the use of passive wheel-on-rah support for the high speed vehicle. Standard steel wheels are capable of handling over 200 mph. The SERAPHIM cost is comparable to that for steel-wheel high-speed ...
Date: June 1995
Creator: Turman, B. N.; Marder, B. M.; Rohwein, G. J.; Aeschliman, D. P.; Kelley, J. B.; Cowan, M. et al.
Partner: UNT Libraries Government Documents Department

Tagential winding coil probes for dipole, quadrupole and sextupole magnet measurements

Description: The number of coils for a rotating coil probe of ``tangential winding geometry depends on the requirements of the magnet measurements. In order to measure the main field, multipole coefficients and the location of the magnetic center axis, two sets of coils are sufficient for a rotating coil probe of ``radial winding geometry.`` A probe of tangential winding geometry, on the other hand, requires more than two sets of coils to measure the above field parameters. This note describes probes of tangential winding geometry with a minimum number of coils for dipole, quadrupole and sextupole magnet measurements.
Date: July 1, 1995
Creator: Kim, S.H.
Partner: UNT Libraries Government Documents Department

Computer aided design of solonoid magnets

Description: Computer programs utilizing Legendre functions and elliptic integral functions have been written to aid in the design of solenoid magnets. The field inside an axisymmetric magnet can be expanded in a converging power series of Legendre functions. The Legendre function approach is very useful for designing solenoid magnets with a high degree of field uniformity. This approach has been programed on the LBL CDC 7600 computer so that one can design an axisymmetric magnet which meets any desired field structure. Two examples of computer designed solenoids are presented. A computer program utilizing elliptic integral functions was also written for the LBL CDC 7600 computer. This method was used in a computer program to verify the results obtained from the Legendre approach and for field calculations within the conductor. The elliptic integral field calculations within the conductor showed that thin solenoids produce field peaking at the ends of the magnet. Computer data is generated for various magnet geometries and compared with theoretical predictions. Computer results and theoretical prediction both show that field peaking is reduced for longer coils, increased for thinner coils and field peaking is a logarithmic function of length, thickness and radius.
Date: June 1, 1978
Creator: DeOlivares, J.M.
Partner: UNT Libraries Government Documents Department

Coil winding development support for the Large Coil Program

Description: A coil winding facility at Oak Ridge National Laboratory has been utilized for the practice winding of the type of conductors used in the Large Coil Program (LCP) on a D shaped bobbin that is approximately 2.5 m x 3.0 m. Pancake and layer windings using copper conductors that simulate LCP-type superconductors have been wound both flat and on edge at tensions up to 8500 N. A method has been developed for winding a pancake coil without splicing the conductor. A small pulsed superconducting coil has been fabricated (63.5-mm bore, 7-T field) to illustrate this spliceless pancake method. This coil also demonstrates that by winding several different superconductors simultaneously, grading can be achieved and space and cost can be optimized. A concept is proposed for winding large Nb/sub 3/Sn superconducting coils before reacting, thus avoiding damage from winding stresses after the conductor is brittle. Also described is a method of insulating after winding and reacting.
Date: January 1, 1979
Creator: Brown, R.L.
Partner: UNT Libraries Government Documents Department

Soft commutated direct current motor [summary of proposed paper]

Description: A novel soft commutated direct current (DC) motor is introduced. The current of the commutated coil is intentionally drained before the brush disconnects the coil. This prevents the spark generation that normally occurs in conventional DC motors. A similar principle can be applied for DC generators.
Date: October 22, 1998
Creator: Hsu, John S.
Partner: UNT Libraries Government Documents Department

High current density, cryogenically cooled sliding electrical joint development

Description: In the past two years, conceptual designs for fusion energy research devices have focussed on compact, high magnetic field configurations. The concept of sliding electrical joints in the large magnets allows a number of technical advantages including enhanced mechanical integrity, remote maintainability, and reduced project cost. The rationale for sliding electrical joints is presented. The conceptual configuration for this generation of experimental devices is highlghted by an approx. 20 T toroidal field magnet with a flat top conductor current of approx. 300 kA and a sliding electrical joint with a gross current density of approx. 0.6 kA/cm/sup 2/. A numerical model was used to map the conductor current distribution as a function of time and position in the conductor. A series of electrical joint arrangements were produced against the system code envelope constraints for a specific version of the Ignition Studies Project (ISP) which is designated as 1025.
Date: September 1, 1986
Creator: Murray, H.
Partner: UNT Libraries Government Documents Department

Pulse voltage circuits

Description: The problems associated with very high voltages may be avoided in part by a variety of pulse-multiplication techniques. These methods are quite varied but share two features, the use of modest dc voltages and the use of switching techniques, to produce in some manner a vectorial transient addition of voltages. Many such methods exist, but only the Marx blank, spiral generator, inversion generator, and Blumlein will be addressed here in detail. Two other methods will be given a brief discussion as matters of interest.
Date: January 1, 1980
Creator: Willis, W.L.
Partner: UNT Libraries Government Documents Department

Analysis of equivalent capacitances between mutually coupled windings

Description: The interwinding capacitance between mutually coupled windings may play a significant role in the transient analysis of these windings. Neglecting this capacitance or dividing it equally among the interwinding node pairs would then result in considerable inaccuracy in the analysis. A method is proposed to calculate equivalent interwinding capacitances which will reduce this inaccuracy. It is illustrated by simple winding models.
Date: January 1, 1986
Creator: Chowdhuri, P.
Partner: UNT Libraries Government Documents Department

Lab 6 winding facility

Description: This note describes the winding machine installed by the facility support group at lab 6 in the Fermilab village. It is available for use by outside users and groups within the lab. The machine can wind wire planes whose longest dimension is less than 10 feet. The Wire spacing range has an upper practical limit of about 5mm. Spacing beyond this requires a very long index time and therefore slows down the winding speed prohibitively.
Date: February 2, 1983
Creator: Guerra, J.; Hansen, S. & Mangene, C.
Partner: UNT Libraries Government Documents Department

Comparative anatomy of dipole magnets or the magnet designer's coloring book

Description: A collection of dipole magnet cross sections is presented together with an indication of how they are related geometrically. The relationships indicated do not necessarily imply the actual path of evolutionary development. Brief consideration is given to magnets of higher multipole order, i.e., quadrupole magnets, etc.). The magnets under consideration have currents parallel to the axis except at the ends, and are long. The relationship between current distribution and magnetic field is essentially two-dimensional. The coils are usually surrounded by an iron yoke, but the emphasis is on conductor-dominated configurations capable of producing a rather uniform magnetic field in the aperture; the iron usually has a small effect.
Date: April 1, 1983
Creator: Meuser, R.B.
Partner: UNT Libraries Government Documents Department

Magnet innovations for linacs

Description: It is possible to produce large magnetic fields at the aperture of permanent magnet quadrupoles, even when the magnetic aperture is very small. That, combined with their compactness, makes permanent magnet quadrupoles very powerful components of small aperture linacs. Results will be presented about past and present work on both fixed and variable strength permanent magnets suitable for use in and around linacs.
Date: June 1, 1986
Creator: Halbach, K.
Partner: UNT Libraries Government Documents Department

Analysis of the multiphase inductor-converter bridge

Description: Analytical derivations are presented for inductor-converter bridge (ICB) circuits in which energy is transferred from a storage inductor to a load inductor with solid state bridges. These derivations provide complete analytical circuit solution in contrast to previously available numerical (non-analytical) procedures. The analysis is based on two parallel methods: (1) Fourier expansion of the inverter waveforms; and (2) a novel method based on the inherent waveforms of the ICB, labeled square functions. Our analytical values of power flow, inductor currents, and voltages compare favorably with the results of a three-phase ICB experiment at Argonne National Laboratory.
Date: January 1, 1979
Creator: Ehsani, M.; Kustom, R.L. & Fuja, R.E.
Partner: UNT Libraries Government Documents Department

Conceptual design for a short-pulse explosive-driven generator

Description: A design is described for a short-pulse explosive-driven generator. The initial flux is provided by a side-fed one-turn coil that is crow-barred at peak field. This field is then compressed by the axially uniform expansion of a cylindrical armature inside the coil. A multistrand helical coil is used to convert the changing flux to voltage at the coaxial output. The circuit is completed by the impact of the armsture against contact rings connected to the helical coil and output. An approximate circuit model is derived. The analysis indicates that several megajoules can be delivered to an inductive load in 0.5 to 5.0 ..mu..s.
Date: January 1, 1986
Creator: Caird, R.S. & Fowler, C.M.
Partner: UNT Libraries Government Documents Department

Transient voltage oscillations in coils

Description: Magnet coils may be excited into internal voltage oscillations by transient voltages. Such oscillations may electrically stress the magnet's dielectric components to many times its normal stress. This may precipitate a dielectric failure, and the attendant prolonged loss of service and costly repair work. Therefore, it is important to know the natural frequencies of oscillations of a magnet during the design stage, and to determine whether the expected switching transient voltages can excite the magnet into high-voltage internal oscillations. The series capacitance of a winding significantly affects its natural frequencies. However, the series capacitance is difficult to calculate, because it may comprise complex capacitance network, consisting of intra- and inter-coil turn-to-turn capacitances of the coil sections. A method of calculating the series capacitance of a winding is proposed. This method is rigorous but simple to execute. The time-varying transient voltages along the winding are also calculated.
Date: January 1, 1985
Creator: Chowdhuri, P.
Partner: UNT Libraries Government Documents Department

Prospects for improved fusion reactors

Description: Ideally, a new energy source must be capable of displacing old energy sources while providing both economic opportunities and enhanced environmental benefits. The attraction of an essentially unlimited fuel supply has generated a strong impetus to develop advanced fission breeders and, even more strongly, the exploitation of nuclear fusion. Both fission and fusion systems trade a reduced fuel charge for a more capital-intensive plant needed to utilize a cheaper and more abundant fuel. Results from early conceptual designs of fusion power plants, however, indicated a capital intensiveness that could override cost savings promised by an inexpensive fuel cycle. Early warnings of these problems appeared, and generalized routes to more economically attractive systems have been suggested; specific examples have also recently been given. Although a direct reduction in the cost (and mass) of the fusion power core (FPC, i.e., plasma chamber, first wall, blanket, shield, coils, and primary structure) most directly reduces the overall cost of fusion power, with the mass power density (MPD, ratio of net electric power to FPC mass, kWe/tonne) being suggested as a figure-of-merit in this respect, other technical, safety/environmental, and institutional issues also enter into the definition of and direction for improved fusion concepts. These latter issues and related tradeoffs are discussed.
Date: January 1, 1986
Creator: Krakowski, R.A.; Miller, R.L. & Hagenson, R.L.
Partner: UNT Libraries Government Documents Department

A comparison of the conductor requirements for energy storage devices made with ideal coil geometries

Description: Superconducting Magnetic Energy Storage (SMES) plants have been proposed in both solenoidal and toroidal geometries. The former is efficient in terms of the quantity of superconductor required per unit of stored energy. For applications where a fringe field could be a problem, the toroidal geometry, which requires at least a factor of two more material, has been proposed. In addition to the solenoid and toroid, other geometries are possible, such as linear multipoles and spherical coils. These geometries have been considered for use in applications other than energy storage. In this report, the effectiveness (quantity of superconductor/stored energy) is calculated for various coil geometries. 7 refs., 4 tabs.
Date: August 1, 1988
Creator: Hassenzahl, W.
Partner: UNT Libraries Government Documents Department

Improved Bundle Divertor Design for ISX-B

Description: The application of Westinghouse's improved bundle divertor design for the ISX-B tokamak at ORNL has been evaluated in detail. The divertor consists of distributed coils with radii increasing outwardly from the plasma plus two auxiliary coils in the vertical plane passing through the center of the divertor and null point of the separatrix. The DITE design that employs nondistributed divertor coils has also been evaluated and compared with the Westinghouse design. There are three major advantages for the Westinghouse design. First, the diverted fluxes are led further away from the plasma and expanded to a larger area; the expansion has been found to be dependent on the divertor coil orientation. Second, the current carried by the divertor coils is reduced and distributed over a larger area; the current density can be reduced by more than a factor of 2. Third, the null points of the separatrices lie approximately on a vertical line instead of on a curve which is convex with respect to the divertor coil. Therefore, more flux can be diverted and uniform shielding could be provided to protect the divertor coil in future reactor applications.
Date: February 1978
Creator: Yang, T. F.
Partner: UNT Libraries Government Documents Department

Performance of R and D sextupole trim coils for SSC (Superconducting Super Collider) dipoles

Description: For the proposed Superconducting Super Collider (SSC), trim coils placed inside the main coils of the dipoles are needed to correct for field nonuniformities due to superconducting magnetization, iron saturation, and systematic construction errors. Four 4.5 m superconducting sextupole trim coils have been made using methods adapted from printed circuit technology and suitable for mass production. This paper presents measurements of the multipoles and quench currents and compares them with SSC requirements. Based on these results, this type of trim coil (''Multiwire'') looks quite promising for use in the SSC.
Date: January 1, 1987
Creator: Wanderer, P.; Herrera, J.; Thompson, P. & Willen, E.
Partner: UNT Libraries Government Documents Department

Plasma engineering for MARS

Description: The two-year Mirror Advanced Reactor Study (MARS) has resulted in the conceptual design of a commercial, electricity-producing fusion reactor based on tandem mirror confinement. The physics basis for the MARS reactor was developed through work in two highly coupled areas of plasma engineering: magnetics and plasma performance.
Date: March 24, 1983
Creator: Carlson, G.A.; Baldwin, D.E. & Barr, W.L.
Partner: UNT Libraries Government Documents Department

Concepts and processes for alternate solenoid coils. Final report. [Fire resistance]

Description: A solenoid coil concept with fire environment potential was proposed, fabricated, and evaluated with favorable results. A polyphenylmethylsiloxane polymer was used as a high temperature insulation coating for the bobbin coil assembly. Alternate concepts utilizing foil conductors and additional insulating materials were examined for follow-on development potential.
Date: February 1, 1979
Creator: Jordan, H.F.
Partner: UNT Libraries Government Documents Department