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Showing papers in "IEEE Transactions on Magnetics in 1975"


Journal ArticleDOI
T. R. McGuire1, R. Potter1
TL;DR: In this paper, the anisotropic magnetoresistance effect in 3D transition metals and alloys is reviewed, which depends on the orientation of the magnetization with respect to the electric current direction in the material.
Abstract: The anisotropic magnetoresistance effect in 3d transition metals and alloys is reviewed. This effect, found in ferromagnets, depends on the orientation of the magnetization with respect to the electric current direction in the material. At room temperature, the anisotropic resistance in alloys of Ni-Fe and Ni-Co can be greater than 5%. The theoretical basis takes into account spin orbit coupling and d band splitting. Other properties such as permeability, magnetostriction, and Hall voltage have no simple relationship to magnetoresistance. Anisotropic magnetoresistance has an important use as a magnetic field detector for digital recording and magnetic bubbles. Such detectors because of their small size are fabricated using thin film technology. Film studies show that thickness, grain size, and deposition parameters play a significant role in determining the percentage change in magnetoresistance. In general, the change is smaller in films than bulk materials. Several tables and graphs that list bulk and film data are presented.

1,581 citations


Journal ArticleDOI
TL;DR: In this article, a review of ferromagnetic metal film magnetoresistors for applications such as read transducers in advanced computer memory and storage technology (mainly bubble domain memories and magnetic recording systems).
Abstract: This paper is a review of ferromagnetic metal film magnetoresistors for applications such as read transducers in advanced computer memory and storage technology (mainly bubble domain memories and magnetic recording systems). Uses of semiconductor Hall effect sensors in this environment are also reviewed, and wherever possible a comparison of the suitability of the two classes of sensors for a particular application is made. The paper includes a phenomenological treatment of galvanomagnetic effects, a brief discussion of materials, design considerations and applications, and a short section on device fabrication techniques.

202 citations


Journal ArticleDOI
W. Wynn, C. Frahm1, P. Carroll, R. Clark, J. Wellhoner, M. Wynn 
TL;DR: In this paper, the most recent gradiometer/magnetometer arrays simultaneously measure five independent spatial gradients of magnetic field and three vector components of the magnetic field, and the measured signals from this array are subjected to a novel signal processing technique which provides detailed information about the magnetic signal source.
Abstract: Recent developments in superconducting magnetic gradiometer technology have led to the construction of advanced ultrasensitive gradiometer/magnetometer arrays. Details of construction techniques and data showing operational capabilities are presented. The most recent of the gradiometer/magnetometer arrays simultaneously measures five independent spatial gradients of the magnetic field and three vector components of the magnetic field. The measured signals from this array are subjected to a novel signal processing technique which provides detailed information about the magnetic signal source.

198 citations


Journal ArticleDOI
TL;DR: In this paper, it was shown that Ni 40 Fe 40 P 14 B 6 (Ni 50 Fe 50 ) alloys with nominal composition of Ni 40Fe 40P 14B 6 are shown to respond to annealing in a magnetic field by reducing the strain-magnetostriction contribution to the anisotropy of straight ribbons.
Abstract: Amorphous alloys with nominal composition of Ni 40 Fe 40 P 14 B 6 are shown to respond to annealing in a magnetic field. Coercive forces are reduced by a factor of 10 to 50 during annealing of straight ribbons to values of 0.003 Oe, as low as ever reported for potentially useful materials. Concurrently the ratio of the magnetization in 1 Oe applied field, to saturation, increases from about 0.5 to 0.95. These changes during annealing correlate with measured stress relief changes. It thus appears that most of the strain-magnetostriction contribution to the anisotropy is removed during annealing. Magnetic annealing at temperatures as low as 100°C results in noticeable changes in properties. From measurements transverse to the magneticaliy induced anisotropy axis, the induced anisotropy is calculated to be about 800 ergs/cm3, considerably smaller than obtained in crystalline Ni 50 Fe 50 . This field-induced anisotropy is reversible in direction and magnitude by reheating the sample to its Curie temperature and then cooling in a field. Annealing of 1.5 cm diameter toroids, made from 50 μm thick tapes, increases the initial permeability by more than a factor of 10 and decreases losses by more than a factor of 10. Losses and permeabilities after heat treatment compare favorably to the Permalloys with similar saturation magnetizations.

181 citations


Journal ArticleDOI
TL;DR: In this article, it has been deduced from the analysis of recording demagnetization mechanism in magnetic recording that in short wavelengths the remanent magnetization exhibits a closed-loop structure in the recording medium.
Abstract: It has been deduced from the analysis of recording demagnetization mechanism in magnetic recording that in short wavelengths the remanent magnetization exhibits a closed-loop structure in the recording medium. In this paper a novel experimental method is presented to confirm the existence of such structure (a circular magnetization mode) and to investigate its mechanism for usual recording medium and heads. The transformation of magnetization from a circular mode to a perpendicular mode is also discussed.

126 citations


Journal ArticleDOI
TL;DR: In this article, the magnetomechanical coupling in highly magnetostrictive Tb x Dy 1-x Fe 2-δ as a function of bias field, x, and δ was measured and a peak coupling factor of 0.6 at x =.26 and bias field of 180 Oe was found.
Abstract: We have measured the magnetomechanical coupling in highly magnetostrictive Tb x Dy 1-x Fe 2-δ as a function of bias field, x, and δ. We find a peak coupling factor of 0.6 at x = .26 and bias field of 180 Oe; the largest reported for a magnetostrictive material. The corresponding material Q is 200. Because of the high magnetostriction, relative permeabilities are necessarily low; \mu_{\max} \simeq 5 . Young's modulus at constant field changes from 4.5 to ll (x1010n/m2) as the bias changes from zero to 4.5 kOe, corresponding to a change in sound velocity >50%. The magnetomechanical coupling factor was also evaluated for 0 \leq \delta \leq .3 . When δ is non-zero a eutectic second phase is present which acts as a toughening agent.

116 citations


Journal ArticleDOI
TL;DR: It is demonstrated that red blood cells may be separated from other blood components using a high gradient magnetic separator and Scanning electron microscopy and free haemoglobin tests show no evidence of serious damage or cell rupture.
Abstract: It is demonstrated that red blood cells may be separated from other blood components using a high gradient magnetic separator. The (SI) magnetic susceptibility of red blood cells is estimated to be 3.88×10-6when the haemoglobin is in the completely deoxygenated state. The magnetic separation effects have been studied using a filter of circular stainless steel wire with flow rates between 10-4ms-1and 6×10-4ms-1and magnetic fields in the range 0.6 to 2.4 T. The results indicate that the filter quickly saturates and the variation of filter performance with field and flowrate is discussed in terms of the force balance and the particle trajectory model. Scanning electron microscopy and free haemoglobin tests on the filtered red blood cells show no evidence of serious damage or cell rupture.

111 citations


Journal ArticleDOI
TL;DR: In this paper, the normal B-H curves of several types of steel are approximated by the equation H = (k 1} e^{k 2}B^{2}} + k 3}) B.
Abstract: The normal B-H curves of several types of steel are shown to be approximated by the equation H= (k_{1} e^{k_{2}B^{2}} + k_{3}) B . The reluctivity ( H/B ) and its derivative with respect to B are given by simple equations that are especially useful in the finite element method of analyzing steel magnetic circuits.

104 citations


Journal ArticleDOI
TL;DR: In this article, a review of the accomplishments and the prospects of forming A15 superconductors using electron beam evaporation is presented, and the techniques of monitoring and controlling the process are discussed.
Abstract: The accomplishments and the prospects of forming A15 superconductors using electron beam evaporation are reviewed. The techniques of monitoring and controlling the evaporation are discussed. The special advantages to the synthesis of A15 materials are pointed out, followed by a number of examples. The prospect of the large scale production of A15 superconductors using electron beam processing is also considered.

103 citations


Journal ArticleDOI
K. Kuijk1, W. van Gestel, F. Gorter1
TL;DR: A short review of bias methods for the magnetoresistive head (MRH), all based on the rotation of the magnetization, is given, and the properties of the various methods are discussed.
Abstract: A short review of bias methods for the magnetoresistive head (MRH), all based on the rotation of the magnetization, is given, and the properties of the various methods are discussed. A novel bias method is proposed which avoids many disadvantages of the former since it is based on the rotation of the current with the aid of slanted conductors, covering the MRH. Measured and calculated static curves are given for this new configuration, for which the name "Barber Pole" is proposed. The Barber Pole turns out to be more linear than a field-biassed MRH. The wavelength response of a Barber Pole is calculated and found to be very similar to that of a normal MRH; this is confirmed by measurements. A two terminal track sensing head, based on the new biassing principle is described.

103 citations


Journal ArticleDOI
TL;DR: In this article, the authors give a chart mostly useful for heating and cooling Mn-Zn-ferrites with a constant oxidation degree, which has five different scales : a logarithmic one for PO 2 (arm), temperature (I/T), scales for Fe 2 O 3 and MnO contents (mole %), and another one for the oxidation degree.
Abstract: We give a chart mostly useful for heating and cooling Mn-Zn-ferrites with a constant oxidation degree. This chart has five different scales : a logarithmic one for PO 2 (arm), temperature (I/T), scales for Fe 2 O 3 and MnO contents (mole %) and another one for the oxidation degree. In the composition range given, with fixed values of PO 2 and T, the accuracy is better than an absolute error of ± 0.1 weight % Fe2+which corresponds to an absolute error of ± 0.002 for the parameter γ. We emphasize the care that must be taken to reach a real equilibrium due to the existence of a phase boundary and of metastable region. This chart has been calculated using two equilibrium constants derived from our experimental studies. Experimentally, the curves log PO 2 = f(1/T) are straight lines with the same slope whatever the composition. This slope corresponds to the enthalpy of transfer of one mole oxygen from the solid phase to the gas phase (ΔH= 66.5 Kcal.)

Journal ArticleDOI
TL;DR: Magnetic fields produced by organs of the human body are being measured in the M.I.T. shielded room, using both a SQUID magnetometer and second-derivative gradiometer, with two potential medical applications.
Abstract: Magnetic fields produced by organs of the human body are being measured in the M.I.T. shielded room, using both a SQUID magnetometer and second-derivative gradiometer. Measurements of the field around the human body can yield new information about the organs which generate current, not available to surface electrodes, and also about organs which contain foreign, ferromagnetic particles. Magnetocardiograms of normal and abnormal heart subjects are being analyzed and visually displayed in order to assess their information content. Magnetoencephalograms recorded from normal and abnormal brain subjects are also under analysis. Measurements have been made of magnetite dust in the lung, with two potential medical applications: the first is the use of pure magnetite dust as a deliberately inhaled tracer (harmless) for pulmonary diagnosis; the second is the assessment of the amount of asbestos accumulated in the lungs of heavily-exposed workers, since most asbestos (harmful) occurs with adhered magnetite.

Journal ArticleDOI
TL;DR: In this article, a particle trajectory model for the calculation of filter performance was extended to include the build-up of multiple layers of particles on the fibers, and good agreement was obtained between the calculated recoveries and purities for all of the particles and the experimentally reported values using a filter packing efficiency and a mechanical trapping term, derived from the CuO data, as adjustable parameters.
Abstract: The experimental performance of a high gradient magnetic separator has been previously reported by other workers in some detail for a CuO/Al 2 O 3 slurry. Less detailed results were also reported for slurries of Mn 2 O 3 , Al, and α-Fe 2 O 3 particles with Al 2 O 3 representing a 20:1 range in particle sizes and a 200:1 range in magnetic susceptibility. Examination of these results indicates that many layers of particles build up on each filter fiber. Accordingly, in this paper we extend the original particle trajectory model for the calculation of filter performance, to include the build-up of multiple layers of particles on the fibers. Good agreement is obtained between the calculated recoveries and purities for all of the particles and the experimentally reported values using a filter packing efficiency and a mechanical trapping term, derived from the CuO data, as adjustable parameters.

Journal ArticleDOI
TL;DR: A review of the magnetic and magneto-elastic behavior of both classical and novel materials having Invar characteristics is given in this article, which is reasonably consistent with the view that they are weak itinerant ferromagnets and allows consistent application of the Landau-Ginzburg theory in which all coefficients are given explicitly in terms of energy band and itinerant electron interaction parameters.
Abstract: A review is given of the magnetic and magnetoelastic behavior of both classical and novel materials having Invar characteristics. Contrary to earlier views many materials having such properties exist which contain no iron and have a fairly homogeneous magnetization. Since these materials may be prepared with different Curie temperatures depending on the alloying content, in principle it is possible to tailor-make Invars with any desired properties. The results of the various experimental investigations on these substances, both classical and novel, are described. They are shown to be reasonably consistent with the view that they are weak itinerant ferromagnets. This view allows the consistent application of the Landau-Ginzburg theory in which all coefficients are given explicitly in terms of energy band and itinerant electron interaction parameters. A very brief review is also given of the application of Invar and related substances to a variety of devices.

Journal ArticleDOI
TL;DR: In this paper, the authors considered the capture of paramagnetic particles, of radius R and susceptibility χ from a slurry, of viscosity η, by a ferromagnetic wire with radius a and saturation magnetization M s, in a uniform magnetic field H o, large enough to saturate the wire, applied perpendicular to the axis of the wire.
Abstract: This paper considers the capture of paramagnetic particles, of radius R and susceptibility χ from a slurry, of viscosity η, by a ferromagnetic wire, of radius a and saturation magnetization M s , in a uniform magnetic field H o , large enough to saturate the wire, applied perpendicular to the axis of the wire. When the slurry is far away from the wire it's velocity is V o . Capture is considered for various orientations of V o with respect to H o . In the calculations the fluid is treated in the inviscid, incompressible approximation. Calculation shows that when M s /2μ o H o is large, the capture radius R c increases with M s /2μ o H o . For values of M s /2μ o H o m /V o , where V m , is the magnetic velocity, V m = (2χM s H o R2/9ηa). The increased performance observed in magnetic filters when μ o H o m /V o , is consistent with the increase of R c with M s /2μ o H o . Effects observed in filters when various configurations of flow in relation to field are used could not be explained in terms of the differences in the bare wire values of R c . It is argued that these differences are due to different dependences of R c on the volume of material captured in the various configurations.

Journal ArticleDOI
TL;DR: In this paper, the authors developed an analytical model of a dense, supercritical helium-cooled superconductor, stabilized to withstand short-term instabilities, allowing for the absorption of energy from transient instabilities and Joule heating during current sharing.
Abstract: We have developed an analytical model of a dense, supercritical helium-cooled superconductor, stabilized to withstand short-term instabilities. The model allows for the absorption of energy from transient instabilities and Joule heating during current sharing. Coolant heat transfer parameters are optimized with respect to geometry and superconductor critical temperatures. Data is presented to demonstrate the advantages of a novel extended surface conductor bundle. This work has been directed at large, high-field magnets in the 5 to 9 Tesla range. Conceptual designs of a toroidal "Tokamak" coil of 6 meter minor diameter and a 10 m. long × 2.5 m. diameter saddle-wound "MHD" magnet are presented.

Journal ArticleDOI
TL;DR: In this paper, the vertical section of the Fe-Cr-Co system at 15 wt%, 1 wt%Nb, and 1 Wt%Al was constructed and the extention of the α phase region of the system was sufficient enough to allow for the solution treatment of the alloys at 25∼30 wtCr content at any temperature above the α 1 +α 2 miscibility gap.
Abstract: The vertical section of the Fe-Cr-Co system at 15 wt%Co, 1 wt%Nb and 1 wt%Al was constructed. The extention of the α phase region of the system was sufficient enough to allow for the solution treatment of the alloys at 25∼30 wt%Cr content at any temperature above the α 1 +α 2 miscibility gap. After step-tempering, their magnetic properties were given as Br = 11.5∼13 KG, Hc = 500∼600 Oe and (BH)max = 4∼5 MGOe. These values were also achieved by continuous cooling from α phase region. The addition of Nb and Al to Fe-Cr-Co system will facilitate a practical manufacturing for producing Fe-Cr-Co permanent magnets.

Journal ArticleDOI
TL;DR: The vector helium magnetometer, one of the Pioneer-Jupiter experiments, has measured the magnetic field of Jupiter and the interplanetary magnetic field in the outer solar system as mentioned in this paper.
Abstract: The vector helium magnetometer, one of the Pioneer-Jupiter experiments, has measured the magnetic field of Jupiter and the interplanetary magnetic field in the outer solar system. The comprehensive scientific objectives of the investigations are explained and are then translated into the major instrument requirements. The principles of operation of the magnetometer, which involve the optical pumping of metastable helium, are discussed and the Pioneer instrument is described. The in-flight performance of the magnetometer is discussed and principal scientific results obtained thus far by the Pioneer investigation are summarized.

Journal ArticleDOI
TL;DR: In this paper, the authors investigated the need for thermalization of the sputtered atoms as they are deposited on the substrate and found that thermalization is required to produce high T c metastable superconducting compounds.
Abstract: To understand the sputtering process as a means of producing high T c metastable superconducting compounds we have investigated the need for thermalization of the sputtered atoms as they are deposited on the substrate. We have used low pressure RF sputtering to produce Nb 3 Ge with T c of ∼ 22°K for pressures of 20 mtorr Kr and for 45 mtorr Ar. To test the hypothesis that a thermalization is required to effect a high T c in Nb 3 Ge we have been studying the sputtering process for systems such as Nb 3 Al where Kr is used to thermalize the Nb atoms with the minimum number of collisions and an admixture of Ne is used to optimally thermalize the Al atoms. A computer simulation of the sputtering process aids in the choice of optimum parameters. If the thermalization hypothesis is correct then co-evaporation should be able to produce high T c Nb 3 Ge.

Journal ArticleDOI
TL;DR: In this article, the dynamic domain configurations of bubbles in garnet materials have been studied using a sampling optical microscope capable of single exposure photographs with a 10 nsec exposure time, where a triggerable flowing nitrogen gas laser pumping a low Q Rodamine 6G Dye laser is used as an illumination source giving light pulses of ∼ 1.5 KW for 10 n sec.
Abstract: The dynamic domain configurations of bubbles in garnet materials have been studied using a sampling optical microscope capable of single exposure photographs with a 10 nsec exposure time. The microscope is an integral part of a sampling system so that the transient shape of the bubble is recorded at various times after a field pulse or, for bubbles in field access devices, during a clock cycle. A triggerable flowing nitrogen gas laser pumping a low Q Rodamine 6G Dye laser is used as an illumination source giving light pulses of ∼1.5 KW for 10 nsec. This light is sufficient to expose Kodak 4 × 16 mm movie film. Standard pulse generators (HP 214A) are used to make free bubble radial velocity measurements. A modified generator allows free bubble collapse measurement to be made. For bubbles propagating at operating frequency within field access devices, a standard bubble exerciser is used, synchronized to the sampling system. In this case, special samples with an internal mirror and epi-mode illumination are used. Illustrative results of bubble domain shapes in a chevron propagating structure and a 90° chevron expander detector are included.

Journal ArticleDOI
TL;DR: In this paper, the superconducting properties of bulk films (0.02-0.06 mm thick) of Nb 3 Ge deposited on Cu substrates by chemical vapor deposition have been studied along with physical parameters characterizing these deposits.
Abstract: The superconducting properties of bulk films(0.02- 0.06 mm thick) of Nb 3 Ge deposited on Cu substrates by chemical vapor deposition have been studied along with physical parameters characterizing these deposits. Results of susceptibility measurements showing superconducting onsets greater than 21 K and resistivity measurements showing onset greater than 22 K are presented along with heat capacity measurements. Data are also presented defining a relationship between superconducting transition temperature and lattice spacing throughout the range of 4 - 21 K. In addition, the effects of substrate temperature and substrate material, as well as mechanical properties such as substrate adherence are described.

Journal ArticleDOI
TL;DR: In this article, the superconducting compound Nb 3 Sn can be produced at the interface of Nb and a Cu-Sn alloy when the composite is heat treated at the proper reaction temperature.
Abstract: It has been demonstrated that the superconducting compound Nb 3 Sn can be produced at the interface of Nb and a Cu-Sn alloy when the composite is heat treated at the proper reaction temperature. This method of Nb 3 Sn preparation was also shown to be particularly suited to the fabrication of (a) Nb 3 Sn multifilamentary composite wires for dc and low frequency applications and (b) low ac loss Nb 3 Sn tapes for 60 Hz applications. The fabrication method and superconducting properties of Nb 3 Sn composite conductors made by this process are reviewed and the metallurgical aspects of the process are discussed. Since practical applications of these composites requires large, high current conductors, methods of producing compound conductors such as cables and braided ribbons which include strengthening and stabilizing components are also discussed and some preliminary results of high current conductors are presented.

Journal ArticleDOI
TL;DR: In this article, a permanent magnet d.c. machine is described, with an axial field and a disc-shaped armature, and the potential distribution is calculated in three-dimensions for high-coercivity magnets, for which a uniform intrinsic magnetisation can be assumed.
Abstract: A permanent magnet d.c. machine is described, with an axial field and a disc-shaped armature. The potential distribution is calculated in three-dimensions for high-coercivity magnets, for which a uniform intrinsic magnetisation can be assumed. This shows the importance of not assuming a constant potential over the pole surface, and of not reducing the system to two-dimensions. The field in the air-gap is found, and a comparison of magnet shapes shows that commonly used circular poles produce poor values of useful field. A compacted mixture of iron powder and epoxy resin has been found to be a good substitute for laminations in the magnetic circuit. It is shown that this material carries about the same flux in the machine as does mild steel. However, it offers a significant reduction in the eddy-current and hysteresis losses, compared with laminated nickel iron.

Journal ArticleDOI
P. Scholten1
TL;DR: In this paper, the average magnetic dipole moment of the particles and the width of the distribution, the magnetic anisotropy field, and the distribution of switching fields are analyzed.
Abstract: Acicular magnetic particles up to about 25 nm thick can be suspended permanently and individually in a liquid. Their orientation by dc and ac magnetic fields can be followed through the induced optical birefringence (Cotton-Mouton effect). Analysis of the field dependencies yields the average magnetic dipole moment of the particles and the width of the distribution, the magnetic anisotropy field, and the distribution of switching fields.

Journal ArticleDOI
TL;DR: In this article, the chemical, morphological, crystallographic, and magnetic properties of solid solutions between cubic iron sesquioxide γFe 2 O 3 and cobalt ferrite CoFe 2O 4 obtained as fine particles by a new preparation method were given.
Abstract: The authors give the chemical, morphological, crystallographic, and magnetic properties of solid solutions between cubic iron sesquioxide γFe 2 O 3 and cobalt ferrite CoFe 2 O 4 obtained as fine particles by a new preparation method. This method gives the whole range of compositions and allows shifting of the magnetic and morphological features in a direction suitable for magnetic recording applications.

Journal ArticleDOI
F. Shelledy1, G. Brock
TL;DR: Analysis of the distortion resulting from imperfect biasing of a magnetoresistive (MR) read head shows that it is unacceptable in wide band recording systems.
Abstract: Evaluation of the distortion resulting from imperfect biasing of a magnetoresistive (MR) read head shows that it is unacceptable in wide band recording systems. A general solution to the problem is presented which involves differentially sensed elements. A practical implementation and performance of a shielded head is discussed. Analytical techniques are shown for designing current-biased MR heads, which allow predictions of performance closely matching experimental results.

Journal ArticleDOI
TL;DR: In this article, the results of initial attempts to produce hard magnetic materials from certain of these materials are reported and analysed in order to identify the major problems still to be overcome, and the implications of these criteria to both alloy composition and production techniques are illustrated for Sm 2 (CO 1-x Fe x ) 17.
Abstract: Criteria governing the successful application of RE 2 T 17 compounds in permanent magnet production are suggested, based upon the experience gained with RECo5materials. The implications of these criteria to both alloy composition and production techniques are illustrated for Sm 2 (CO 1-x Fe x ) 17 . In this respect the primary magnetic properties of these compounds, derived from single crystal measurements, are presented. The results of initial attempts to produce hard magnetic materials from certain of these materials are reported and analysed in order to identify the major problems still to be overcome.

Journal ArticleDOI
TL;DR: In this paper, a study has been made of the possibility of making Nb 3 Al wires by interdiffusion between Al and Nb at relatively low temperatures (lower than 1000°C).
Abstract: A study has been made of the possibility of making Nb 3 Al wires by interdiffusion between Al and Nb at relatively low temperatures (lower than 1000°C). This method should allow the fabrication of a copper stabilized wire by coworking Nb and Al composites in a copper matrix before the diffusion treatment. Results concerning the diffusion temperature and time de pendence of J c and T c are presented. While J c (64kG) is quite high, of the order of 1.5×105A/cm2, T c is 15.56°K, lower than the usually reported value. X- -ray measurements of the lattice parameter are also reported and correlated with the measured value of T c .

Journal ArticleDOI
TL;DR: In this paper, a comparison of the various energy storage systems is presented in terms of performance on electric power systems, and cost, and a brief review of the Los Alamos Scientific Laboratory program on superconducting magnetic energy storage is included.
Abstract: As the cost of fossil fuel has increased and the load factors on electric utilities have decreased, the need for efficient, reliable energy storage systems has increased. Although pumped hydro storage is now used extensively on those utility systems having the appropriate resources nearby, it is only 65% efficient. Superconducting magnetic energy storage which promises to be more than 90% efficient and easily sited may become a competitive energy storage technology. A comparison of the various energy storage systems is presented in terms of performance on electric power systems, and cost. Emphasis is given to the various technologies involved in the development of large superconducting magnets. A brief review of the Los Alamos Scientific Laboratory program on superconducting magnetic energy storage is included.

Journal ArticleDOI
P. Gueret1
TL;DR: In this paper, it was shown both by computer simulations and experimentally that a single Josephson junction has memory and can therefore be used for information storage and means of reading-out the information content of such a memory element are demonstrated.
Abstract: It is shown both by computer simulations and experimentally that a single Josephson junction has memory and can therefore be used for information storage. Means of reading-out the information content of such a memory element are demonstrated. Finally, memory operation, writing and reading, is described as a direct application of these concepts.