• Title/Summary/Keyword: magnetization system

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Precision Determination of Anisotropy Constant $K_1$from Magnetization Curve of Partially Aligned Unaxial Anisotropy System

  • Kim, Yoon-Bae;Kim, Hyoung-Tae
    • Journal of Magnetics
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    • v.6 no.4
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    • pp.142-144
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    • 2001
  • A method to deduce the rotational magnetization curve from experimental magnetization of partially aligned uniaxial anisotropy system has been investigated. The curve obtained by this process has been evaluated quire close to the theoretical magnetization curve compared to that obtained by linear extrapolation from high field data. This new approach offers better accuracy for the determination of magnetic anisotropy by fitting a calculated magnetization curve to the obversed one.

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Implementation of High Magnetization System for Performance Enhancement of Magnetic Flux Leakage Tool

  • Cho, Sung-Ho;Yoo, Hui-Ryong;Kim, Dong-Ku;Park, Dae-Jin;Rho, Yong-Woo;Seo, Kang;Park, Gwan-Soo;Choi, Doo-Hyun;Song, Sung-Jin
    • Journal of Magnetics
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    • v.15 no.4
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    • pp.199-203
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    • 2010
  • This paper discusses the effectiveness of high magnetization saturation in ILI (In-Line Inspection) using an MFL (Magnetic Flux Leakage) tool, and introduces a practical method for improving the magnetization level together with the piggability. Thin steel plates, replacing the conventional wire brushes were used as conductors to transfer the magnetic flux to the pipe wall. The newly designed MFL tool was compared with the conventional version by means of FEM (Finite Element Method) analysis and full-scale experiments. In the results, the newly developed magnetization system obtained a stronger MFL signal amplitude, specially 2.7 times stronger, than that obtained by the conventional magnetization system for the same defect dimensions.

Temperature Dependence of Magnetic State of Fe/Al Multilayered Films

  • Lee, S. J.;J. S. Baek;Kim, Y. Y.;W. Y. Lim;W. Abdul-Razzaq
    • Journal of Magnetics
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    • v.2 no.3
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    • pp.93-95
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    • 1997
  • We investigated the temperature dependence of magnetization of Fe/Al multilayers fabricated by dc magnetron sputtering system. As the temperature increased from 5 K in a low magnetic field (100G) the magnetization of the samples increased and made a broad peak at some critical temperature. Further increase of temperature decresed the magnetization as an ardinary ferromagnetic curve. Part of samples show rapid increase of magnetization at low temperature. A model developed in this study suggests that the biquadratic coupling yields such a rapidly increasing behavior of magnetization at low temperature.

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Characteristic Analysis of Permanent-Magnet Linear Eddy-Current Brake System According to Magnetization Pattern (자화패턴에 따른 영구자석 직선형 와전류 제동장치의 특성 해석)

  • 이성호;조한욱;장석명
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.52 no.9
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    • pp.427-433
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    • 2003
  • Permanent magnet movers with three different magnetization patterns were applied to a linear eddy current braking system. By using a two-dimensional analytical technique, this paper deals with the comparison of the design guidelines, magnetic field, required magnet volume, and force capability for three types of linear brakes. The analytical results are also verified by finite element analyses.

Experimental study on the correlation between measurement length and winding or twist pitch for magnetization loss occurring in CORC and TSTC

  • Ji-Kwang Lee;Jinwoo Han;Kyeongdal Choi;Woo-Seok Kim
    • Progress in Superconductivity and Cryogenics
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    • v.25 no.4
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    • pp.40-44
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    • 2023
  • For high-temperature superconducting power applications that need large current capacity, a large current conductor manufactured using multiple superconducting tape is required. Conductors being studied for large currents capacity such as CORC, TSTC, and RACC have advantages and disadvantages, and in order to use these conductors in coil form and apply them to AC power devices, research on magnetization loss occurring in superconductors due to external magnetic fields is essential. To accurately measure magnetization loss in a conductor that is twisted by stacking straight conductors like TSTC, the correlation between the measuring system and the shape of the sample must be clearly known to accurately measure the loss. In this paper, we will confirm the difference in magnetization loss measurement values according to the correlation between the length of the pickup coil and the twist pitch of the sample in CORC and TSTC shapes, and review considerations for accurate magnetization loss measurement from the results.

Setup and Operating Characteristics of the Experimental Apparatus for Magnetization Measurements of Sperconductor (초전도체 자화특성 측정을 위한 실험장치의 구축 및 그 동작 특성)

  • 최세용;나완수;주진호
    • Progress in Superconductivity and Cryogenics
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    • v.1 no.2
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    • pp.30-36
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    • 1999
  • Superconductors are dissipative when exposed to time-varying magnetic fields. To analyze the AC characteristics of a superconductor, one usually needs to know magnetization curves of it. Good magnetization curves can be obtained only in homogeneous magnetic filed. In This paper, we report the setup and test results of a magnetization measurement system, which consists mainly of frequency-variable power supply and homeogenous magnet with 7-cm long air gap. Special emphasis are foused on the design and fabrication of the magnet, which aims to give background magnetic fields, and on the overall characteristics of the system.

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Design of the Magnetization System of the Permanent Magnet in Magnetic Sensors (마그네틱 위치 센서용 영구자석의 착자 시스템 설계)

  • Jeong, Seung-Ho;Lee, Chul-Kyu;Kwon, Byung-Il
    • Proceedings of the KIEE Conference
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    • 2005.07b
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    • pp.1029-1031
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    • 2005
  • A magnetic position sensor is a apparatus that detect the rotating position by measuring the value of the flux density of the rotating position. In this paper, the magnetization system of the permanent magnet in the magnetic position sensor which detects the rotating position was designed. The permanent magnet was magnetized for the flux density into the hole element to be sinusoidal distribution according to the rotating position. To make the sinusoidal distribution of flux density, the magnetization values according to the position in permanent magnet were varied by adjusting the air gap between the pole of the magnetization fixture and the surface of the permanent magnet.

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Study of the Magnetization Reversal Behavior of exchange-Biased System Using Polarized Neutron Reflectometry

  • Park, Sung-Kyun;Kim, Ki-Yeon;Kim, Ji-Wan;Choi, Hyeok-Cheol;Teichert, A.;You, Chun-Yeol;Shin, Sung-Cheol;Lee, Jeong-Soo;Fitzsimmons, M.R.
    • Proceedings of the Korean Magnestics Society Conference
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    • 2011.06a
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    • pp.3-3
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    • 2011
  • Since the first discovery of exchange anisotropy on Co/CoO system[1], there have been numerous studies to explore the physical origin of exchange-biased system[2,3]. In this presentation, we report that how the polarized neutron reflectomery can be applied to study the magnetization reversal behavior of the exchange biased system. As an example, the detailed magnetization reversal mechanism of the exchange-biased Py(30 nm)/FeMn (0, 15, 30 nm)/CoFe(30 nm) trilayers was studied and found that the 15 nm antiferromagnetic FeMn layer mediates the magnetization reversal behaviors of both Py and CoFe layers through interlayer exchange bias coupling. We also update the current activities in polarized neutron reflectometer in HANARO.

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A Study on the Microstructures and Electromagnetic Properties of Al-Co/AlN-Co Thin Films

  • Han, Chang-Suk;Han, Seung-Oh
    • Journal of the Korean Society for Heat Treatment
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    • v.24 no.1
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    • pp.16-22
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    • 2011
  • Al-Co/AlN-Co multilayer films with different layer thicknesses were prepared by using a two-facing target type D.C sputtering (TFTS) system. The deposited films were annealed isothermally at different temperatures and their microstructure, magnetic properties and resistivity were investigated. The magnetization of as-deposited films is very small irrespective of layer thickness. It was found that annealing conditions and layer thickness ratio (LTR) of Al-Co to AlN-Co can control the microstructure as well as the physical properties of the prepared films. The resistivity and magnetization increase and the coercivity decreases with decreasing LTR. High resistivity and sufficient magnetization were obtained for the films with LTR = 0.35. Films having such considerable magnetization and resistivity will be a potential candidate to be used for a high density recording material.

A study on the effect of cross magnetization to the generator parameters and simplified linear model (교차자화 포화효과에 의한 발전기 정수와 간략모델에 미치는 영향에 관한 연구)

  • Kim, Deok-Young;Kwon, Sae-Hyuk
    • Proceedings of the KIEE Conference
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    • 1999.07c
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    • pp.1236-1238
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    • 1999
  • This paper presents an effect of cross magnetization to the generator simplified linear model which is used for multi-machine power systems. The formulae of reactances and time constant with saturation effect are presented. The simulation results show that cross magnetization has an effect which can not be ignored, to the reactances, time constant and eigenvalues in one machine infinite bus system of simplified linear model.

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