• Title/Summary/Keyword: magnetic probe

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Probe Recording in Magnetic Patterned Media

  • Abelmann, Leon;Siekman, Martin;Murillo, Rogelio;Groenland, J.P.J. (Hans)
    • Transactions of the Society of Information Storage Systems
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    • v.3 no.2
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    • pp.86-93
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    • 2007
  • In this paper we explain why future probe storage systems will use patterned media. As a model system, magnetic patterned media will be discussed, even though their data density is limited to about $7Tbit/in^2$. The first results on magnetic probe storage on patterned media are presented, and the problem of switching field distribution is discussed in detail. Finally we will present the first steps into two-dimensional coding for patterned media.

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Simulation of a Langmuir Probe in an ECR Reactor (ECR Reactor 내의 Langmuir Probe 시뮬레이션)

  • Kim, Hoon;Porteous, Robert K.;Boswell, Rod W.
    • Proceedings of the KIEE Conference
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    • 1994.07b
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    • pp.1609-1611
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    • 1994
  • In ECR and helicon reactors for plasma processing, a high density plasma is generated in a source region which is connected to a diffusion region where the processing takes place. Large density and potential gradients can develop at the orifice of the source which drive ion currents into the diffusion region. The average ion velocity may become the order of the sound velocity. Measurements of the ion saturation current to a Langmuir probe are used as a standard method of determining the plasma density in laboratory discharges. However, the analysis becomes difficult in a steaming plasma. We have used the HAMLET plasma simulator to simulate the ion flow to a large langmuir probe in an ECR plasma. The collection surface was aligned with the Held upstream, normal to the field, and downstream. ion trajectories through the electric and magnetic fields were calculated including ion-neutral collisions. We examines the ratio of ion current density to plasma density as a function of magnetic field and pressure.

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A Study on the Measurement of Magneto-Plasma Parameters by Probe Method (자화 플라즈마 파라메타 측정에 관한 연구)

  • Sung, Y.M.;Lee, C.Y.;Son, J.B.;Shin, J.H.;Kwak, Y.S.;Park, C.H.
    • Proceedings of the KIEE Conference
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    • 1993.07b
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    • pp.591-593
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    • 1993
  • Magneto plasma has been widely used for controlled fusion and material processings such as etchings, depositions, and sputterings in the various fields. For controlling and guaranting the equipment, precision plasma parameters must be gained. In this experiment, using single probe and double probes, we investigated the effect of magnetic field on magneto plasma. As a result of this experiment, we found the fact that single probe was largely affected by magnetic field for measuring magneto plasma parameters, while double probe was not.

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The simulator loop probe style magnetic stimulation design for a nervous system treatment (신경계 치료를 위한 루프 프로브형 자기자극기의 시뮬레이터)

  • Kim, Whi Young
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.5 no.3
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    • pp.29-37
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    • 2009
  • It is as result that study to apply mini magnet nerve curer in peripheral nervous system disease treatment. Simulator and embodied action power and Control Unit in cylinder form of magnet roof object firstly. Yielded service area about special quality of probe of loop object cylinder style and treatment area dimension and distance of treatment pulse secondly. Embody pulse forming course energy value by Probe's form by third, could embody treatment pulse by disease. Specially, through a special quality experiment, saved Damping pulse form and treatment digital forming etc. variously. Lately, embodied this to aid a little in disease treatment that follow that there is no invasion that there is no stimulation by medicine development. Neuralgia, muscular disease and Altzheimer, with stroke etc. is becoming the matter of concern and interest which disease of adult etc. it is same is important. And the melancholia in compliance with the modern direction of a ceremony which is complicated and garrulous, trillion it will cry and symptoms, it is a tendency where the emotional obstacle etc. nervous psychiatric disorder patient is increasing at class speed. But currently the applicator it will be able to treat like this disease almost it is a condition which is wholly lacking. Consequently like this disease it used magnetic stimulation and it diagnosed and the equipment it will be able to treat plan and it embodied.

Development of magnetic field measurement system for AMS cyclotron

  • Ho Namgoong;Hyojeong Choi;Mitra Ghergherehchi;Donghyup Ha;Mustafa Mumyapan;Jong-Seo Chai;Jongchul Lee;Hoseung Song
    • Nuclear Engineering and Technology
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    • v.55 no.8
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    • pp.3114-3120
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    • 2023
  • A high-accuracy magnetic field measurement device based on a cyclotron is being developed for accelerator mass spectrometry (AMS). In this study, a magnetic field measurement device consisting of a Hall probe sensor, piezo-motor, and step motor was developed to measure the magnetic field of the AMS cyclotron magnet. The Hall probe sensor was calibrated to achieve positional accuracy by using polar coordinates. The measurement results between the ratchet gear and piezo-motor, which are the instruments used for driving the measurement device, were analyzed. The measurement result of the device with a piezo-motor exhibits a difference of 5 Gauss (0.04%) as compared with the simulation result.

The Electrical Characterization of Magnetic Tunneling Junction Cells Using Conductive Atomic Force Microscopy with an External Magnetic Field Generator

  • Heo, Jin-Hee
    • Transactions on Electrical and Electronic Materials
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    • v.11 no.6
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    • pp.271-274
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    • 2010
  • We examined the tunneling current behaviors of magnetic tunneling junction (MTJ) cells utilizing conductive atomic force microscopy (AFM) interfaced with an external magnetic field generator. By introducing current through coils, a magnetic field was generated and then controlled by a current feedback circuit. This enabled the characterization of the tunneling current under various magnetic fields. The current-voltage (I-V) property was measured using a contact mode AFM with a metal coated conducting cantilever at a specific magnetic field intensity. The obtained magnetoresistance (MR) ratios of the MTJ cells were about 21% with no variation seen from the different sized MTJ cells; the value of resistance $\times$ area (RA) were 8.5 K-12.5 K $({\Omega}{\mu}m^2)$. Since scanning probe microscopy (SPM) performs an I-V behavior analysis of ultra small size without an extra electrode, we believe that this novel characterization method utilizing an SPM will give a great benefit in characterizing MTJ cells. This novel method gives us the possibility to measure the electrical properties of ultra small MTJ cells, namely below $0.1\;{\mu}m\;{\times}\;0.1\;{\mu}m$.

Residual magnetic field profiles and their current density profiles of coated conductors for fast and slow cut-off current operations

  • Sun, J.;Tallouli, M.;Shyshkin, O.;Hamabe, M.;Watanabe, H.;Chikumoto, N.;Yamaguchi, S.
    • Progress in Superconductivity and Cryogenics
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    • v.17 no.1
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    • pp.17-20
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    • 2015
  • Coated conductor is an important candidate for power cable applications due to its high current density. Even for DC power cable transmission, we must study the transport properties of HTS tapes after slow and fast discharge. In order to evaluate relation of the magnetic field with applied current we developed a scanning magnetic field measurements system by employing a Hall probe. This work presents the measurements of the magnetic fields above a coated conductor by varying applied current pattern. In the work, a transport current of 100 A, less than the critical current, is applied to YBCO coated conductor. We measured the residual magnetic field distributions after cut off the transport current with slow and fast operations. The results show differences of the magnetic field profiles and the corresponding current profiles by an inverse solution from the magnetic field measurement between these two operations because of the hysteresis of coated conductor excited by the transport current.

Measurement using Low-temperature Scanning Hall Probe Microscopy and Analysis of Local Current Distribution using Inversion Problem Technique (저온 주사 홀소자 현미경과 역변환 방법을 이용한 국소적 전류 분포 분석)

  • Cho, B.R.;Park, S.K.;Park, H.Y.;Ri, H.C.
    • Progress in Superconductivity
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    • v.13 no.1
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    • pp.34-39
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    • 2011
  • We have performed measurements of the local magnetic field distribution of YBCO coated conductors using Low-temperature Scanning Hall Probe Microscopy (LT-SHPM). Distribution of stray magnetic field of various types of YBCO coated conductors in the superconducting state was measured in presence of external magnetic fields. We analyzed one dimensional and two dimensional local current distribution using inversion technique from the magnetic field distribution.

Design of Current Probe Using Faraday Effect of Optical Fiber (광 파이버의 패러데이 효과를 이용한 전류측정용 프로브 설계)

  • Kang, Hang-Sik;Kim, Chul-Ju
    • Proceedings of the KIEE Conference
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    • 1995.07c
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    • pp.1278-1280
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    • 1995
  • A probe type fiber-optic sensing techique for electric current measurement is applied in this paper. The technique is based on the Faraday effect which meaning is that polarization state of light is rotated by magnetic field. In experiment, test wire is located at inside and outside of the probe to be measured. The experimental results prove not only linear property, but also polarization rotation property according to the distance from outside of probe.

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