By Topic

Magnetics, IEEE Transactions on

Issue 6 • Date November 1978

Filter Results

Displaying Results 1 - 17 of 17
  • [Front cover and table of contents]

    Publication Year: 1978 , Page(s): 0
    Save to Project icon | Request Permissions | PDF file iconPDF (1498 KB)  
    Freely Available from IEEE
  • Eight-micron period bubble devices

    Publication Year: 1978 , Page(s): 1117 - 1122
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (680 KB)  

    Magnetic bubble shift register devices of 68 121- and 266 473-bit capacity have been fabricated and tested. The epitaxial garnet bubble films were nominally 1.7 μm thick, supported nominally 1.7-μm diameter bubbles, and had collapse fields of about 260 Oe. The storage area per bit was 64 μm2, which was realized with a minimum coded feature dimension of 1 μm and contact photolithography using EBES chrome masters. Initial yields obtained in two experimental batches each of the two chip capacities are discussed. Parametric test results are presented for generator current, transfer current and phase, and rotating field intensity. Nominal values have been established to be 130-mA generate current, 21-mA transfer current, and 60-Oe drive. The detector signals were about half as large as normally obtained from 3.3-μm bubble devices with comparable resistance and conventional design. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Major-minor loop chips adapted for associative search in relational data base

    Publication Year: 1978 , Page(s): 1123 - 1128
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (664 KB)  

    Unique features of bubble devices are exploited for data base applications. Columnized storage and retrieval ensure minimum input/output data traffic. Dynamic indexing loops in synchronization with data storage loops allow convenient indexing during data qualification and eliminate redundant traversing of disqualified data. Such hardware features are unavailable in disk files, but prove particularly advantageous for associative search. A bubble chip design based on slight modification of conventional major/minor loops is described, which is suitable for relational data base applications. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Distribution of magnetization in elements on chevron detector

    Publication Year: 1978 , Page(s): 1129 - 1132
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (456 KB)  

    The magnetization distribution in elements of bubble domain chevron detector is first investigated using the magnetooptical micromagnetometer technique. Distribution curves of in-plane magnetization components are obtained in all types of elements. It is found that the magnetization distribution in elements having interconnections is very different from those having none. It is shown that the magnetization distribution in a chevron which is in row, is not equivalent to the one beyond it. It is shown that the magnetization component on the chevron leg perpendicular to the field is more than zero and amounts to Msat the center of the chevron. Fields are determined in which there are remagnetization and redistribution of magnetization in bubble domain chevron detector. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Total magnetic fields and read characteristics of infinite length pole piece magnetic recording heads

    Publication Year: 1978 , Page(s): 1132 - 1140
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (792 KB)  

    Magnetic recording head fields generated by current distributions of zero total current flux are calculated considering the two topological possibilities for the current elements being either external to infinite permeability pole pieces or contained entirely within the pole pieces. The frequency response for each of these field configurations is determined by application of the fast Fourier transform. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Some problems concerning the accuracy and efficiency of self-consistent iterative calculations in magnetic recording

    Publication Year: 1978 , Page(s): 1141 - 1148
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (808 KB)  

    There is an increasing interest in the so-called dynamic self-consistent iterative calculations to predict flux reversal patterns in magnetic recording. In the literature one can observe a certain amount of incoherence in the choice of approximations and of numerical methods. The effect of some of the usual approximations are investigated in a systematic way and a new approach in the formulation of the problem is introduced which leads to a considerable gain in efficiency. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Magnetic traction force in an HGMS with an ordered array of wires: I

    Publication Year: 1978 , Page(s): 1148 - 1154
    Cited by:  Papers (5)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (656 KB)  

    The magnetic traction force, experienced by a paramagnetic sphere inside an infinite ordered array of wires that forms the matrix of an HGMS, is calculated. A comparison is made, for a particular case, with the forces (exact and approximate) due to a single wire and to two wires. It is found that the single wire forces are reasonably good approximations for high applied fields and small filling factors provided they are made to vanish midway between two adjacent wires. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Magnetic traction force in an HGMS with an ordered array of wires: II

    Publication Year: 1978 , Page(s): 1155 - 1157
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (264 KB)  

    An ordered HGMS is considered whose separating medium consists of an infinite face centered array of wires. The force experienced by a paramagnetic sphere inside the array is calculated and found to be larger than that in a simple array, or than the force due to a single wire. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Particle flow and collection process in single wire HGMS studies

    Publication Year: 1978 , Page(s): 1158 - 1164
    Cited by:  Papers (27)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1168 KB)  

    A television system for the observation of HGMS particle flow and buildup on a ferromagnetic wire or small array of wires is described for three geometries. Data for the collection process and a sequence of pictures of buildup are presented for Mn2P2O7, Mn2O3, and Cr2O3particles collected on 125 μm nickel wires. The wake, formed in some cases downstream from the particle collection, has been studied. Data on the wake is given and compared with published data on wake formation. New results on downstream and upstream collection on a wire as a function of slurry velocity is presented. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Laminar flow model of particle capture of axial magnetic filters

    Publication Year: 1978 , Page(s): 1165 - 1169
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (424 KB)  

    Existing theories of particle capture in high gradient magnetic separation are limited by the widespread use of the model of ideal frictionless potential flow. The high symmetry associated with the axial capture configuration enables the elements of Newtonian fluid flow to be incorporated into a new theory of particle capture. In this, expressions both for filter impedance and for extraction efficiency are obtained. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • ΔE effect and magnetomechanical coupling factor in Fe80B20and Fe78Si10B12glassy ribbons

    Publication Year: 1978 , Page(s): 1169 - 1171
    Cited by:  Papers (2)  |  Patents (7)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (288 KB)  

    Field annealing experiments on amorphous Fe80B20ribbon (Metglas 2605) and amorphous Fe78Si10B12ribbon (Tsuya, Tohoku University) are reported. The maximum magnetomechanical coupling constant, k , and change in Young's modulus, ΔE/E0found in Fe80B20were 0.64 and 0.87, respectively, for an anneal of 376° for 6 min in a field of 2.0T. The maximum k for Fe78Si10B12was found to be 0.82, following a similar anneal at 373°C. This is higher than 0.75 reported by Tsuya and Arai for Fe78Si10B12, previously the highest known for any material. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Inductive measurement of metallic cylindrical shells

    Publication Year: 1978 , Page(s): 1171 - 1174
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (368 KB)  

    The thickness of thin cylindrical copper shells of radius a and thickness D(D/a < 0.15) were measured by means of an inductive measurement. The samples were obtained by chemical reduction of thick copper pipes. The conductivity of the cylinders was measured by a standard four-terminal technique. The agreement between the value of thickness measured mechanically and the value obtained from inductive measurement is of the order of ±2 percent. Thicker brass shells were measured and these results compared with theory. The extension of the inductive measurement to cylindrical shells covering cylinders with a finite conductivity is also discussed. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • On the magnetic field of a finite array of cylindrical ferromagnetic bars--Part I

    Publication Year: 1978 , Page(s): 1175 - 1179
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (384 KB)  

    A new approach is suggested for calculating and measuring the two-dimensional magnetic field of an array of cylindrical ferromagnetic bars in a uniform magnetic field. The field is determined with allowance for mutual magnetization of the bars in a finite array. It is shown that the array can amplify the external uniform field and its gradient to different degrees, thereby increasing the magnetic forces. The method is reasonably accurate and convenient in use; theory and experimental results are in good agreement. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Interactive computer program for coil geometry data base generation and manipulation

    Publication Year: 1978 , Page(s): 1180 - 1185
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (536 KB)  

    An interactive computer program GMAN has been developed to facilitate the generation and manipulation of coil geometry data bases required for three-dimensional magnetic field analyses. GMAN was designed specifically to be used in conjunction with the three-dimensional field analysis program EFFI developed at the Lawrence Livermore Laboratory. GMAN generates the coil geometry data elements from curves representing centerlines of windings. It can also be used to perform geometrical (symmetry) manipulations on the data elements. The design goal of the program is that it be versatile and easy to use so that the generation and modification of coil geometry data bases can be accomplished with a minimum amount of effort. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • On the validity of characterizing eddy current phenomena by parabolic partial differential equations

    Publication Year: 1978 , Page(s): 1185 - 1186
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (256 KB)  

    Eddy current problems are commonly solved by neglecting displacement current. This assumption reduces Maxwell's equations to a parabolic partial differential equation [1]. It is shown that neglecting displacement currents entirely may reduce the space dimension of the problem and yields the magnetic and electric fields in the conducting regions accurately. However, the electric fields in the air regions are very inaccurate, and the charge distribution resulting on the conducting surfaces is absent in the standard solution, which neglects displacement currents and longitudinal field variations. The standard solution is found to yield the proper value of skin depth over a very wide range of conductivity, permeability, and frequency. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Correction to "Magnet measurements for digital magnetic recording"

    Publication Year: 1978 , Page(s): 1187
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (131 KB)  

    First Page of the Article
    View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • [Back cover]

    Publication Year: 1978 , Page(s): 0
    Save to Project icon | Request Permissions | PDF file iconPDF (3402 KB)  
    Freely Available from IEEE

Aims & Scope

IEEE Transactions on Magnetics publishes research in science and technology related to the basic physics and engineering of magnetism, magnetic materials, applied magnetics, magnetic devices, and magnetic data storage.

Full Aims & Scope

Meet Our Editors

Editor-in-Chief
Pavel Kabos
National Institute of Standards and Technology