NDLI: Magnetic field inhomogeneity and torque in high temperature superconducting magnetic bearings

Content Provider	IEEE Xplore Digital Library
Author	Matsumura, T. Hanany, S. Hull, J.R. Johnson, B. Jones, T.
Copyright Year	2002
Abstract	We give experimental evidence for the connection between magnetic field inhomogeneity of a permanent magnet and torque on the rotor in a high temperature superconducting bearing. Spin-down measurements below 14 Hz are used to demonstrate a high degree of correlation between variations in the angular speed of the rotor within a single period of rotation with the measured spatial structure of the magnetic field of the rotor. At frequencies below /spl sim/1 Hz the fractional speed variation within a single period of rotation is inversely proportional to the square of the mean frequency of rotation. We propose that a dipole-dipole interaction gives rise to the torques that lead to speed variations and we show that this interaction explains the observed functional dependence on frequency. At frequencies above /spl sim/1 Hz the measured magnitude is about 1% of the mean frequency of rotation, consistent with the noise level in the experiment. The results imply that arcminute accuracy angular encoding of the rotor can be achieved with a single measurement of angle in each period.
Sponsorship	Council on Superconductivity Appl. Superconductivity Conference Inc MIT
Starting Page	2316
Ending Page	2319
Page Count	4
File Size	167923
File Format	PDF
ISSN	10518223
Volume Number	15
Issue Number	2
Language	English
Publisher	Institute of Electrical and Electronics Engineers, Inc. (IEEE)
Publisher Date	2005-06-01
Publisher Place	U.S.A.
Access Restriction	One Nation One Subscription (ONOS)
Rights Holder	Institute of Electrical and Electronics Engineers, Inc. (IEEE)
Subject Keyword	Magnetic fields Torque High temperature superconductors Magnetic levitation Magnetic field measurement Frequency Rotation measurement Superconducting magnets Velocity measurement Permanent magnets superconducting magnetic bearing Polarimeter for observational cosmology
Content Type	Text
Resource Type	Article
Subject	Condensed Matter Physics Electronic, Optical and Magnetic Materials Electrical and Electronic Engineering

Sl.	Authority	Responsibilities	Communication Details
1	Ministry of Education (GoI), Department of Higher Education	Sanctioning Authority	https://www.education.gov.in/ict-initiatives
2	Indian Institute of Technology Kharagpur	Host Institute of the Project: The host institute of the project is responsible for providing infrastructure support and hosting the project	https://www.iitkgp.ac.in
3	National Digital Library of India Office, Indian Institute of Technology Kharagpur	The administrative and infrastructural headquarters of the project	Dr. B. Sutradhar bsutra@ndl.gov.in
4	Project PI / Joint PI	Principal Investigator and Joint Principal Investigators of the project	Dr. B. Sutradhar bsutra@ndl.gov.in Prof. Saswat Chakrabarti will be added soon
5	Website/Portal (Helpdesk)	Queries regarding NDLI and its services	support@ndl.gov.in
6	Contents and Copyright Issues	Queries related to content curation and copyright issues	content@ndl.gov.in
7	National Digital Library of India Club (NDLI Club)	Queries related to NDLI Club formation, support, user awareness program, seminar/symposium, collaboration, social media, promotion, and outreach	clubsupport@ndl.gov.in
8	Digital Preservation Centre (DPC)	Assistance with digitizing and archiving copyright-free printed books	dpc@ndl.gov.in
9	IDR Setup or Support	Queries related to establishment and support of Institutional Digital Repository (IDR) and IDR workshops	idr@ndl.gov.in

Application of high temperature superconductors on levitation bearings, torque transmissions and vibration dampers

A measurement of rotation loss characteristics of high-Tc superconducting magnetic bearings and active magnetic bearings

Homogenization of the magnetic field in the air-gap of a permanent magnet superconductor bearing

Axial bearings using superconductors and permanent magnets

Gravimeter using high-temperature superconducting bearing

Lumped-Parameter Model to Describe Dynamic Translational Interaction for High-Temperature Superconducting Bearings

Levitation force of multi-block YBaCuO bulk high temperature superconductors

Studies on high temperature superconducting permanent magnet

Improvement and evaluation of bearing stiffness in high T/sub c/ superconducting magnetic bearing

Magnetic field inhomogeneity and torque in high temperature superconducting magnetic bearings

Similar Documents

Application of high temperature superconductors on levitation bearings, torque transmissions and vibration dampers

A measurement of rotation loss characteristics of high-Tc superconducting magnetic bearings and active magnetic bearings

Homogenization of the magnetic field in the air-gap of a permanent magnet superconductor bearing

Axial bearings using superconductors and permanent magnets

Gravimeter using high-temperature superconducting bearing

Lumped-Parameter Model to Describe Dynamic Translational Interaction for High-Temperature Superconducting Bearings

Levitation force of multi-block YBaCuO bulk high temperature superconductors

Studies on high temperature superconducting permanent magnet

Improvement and evaluation of bearing stiffness in high T/sub c/ superconducting magnetic bearing

Magnetic field inhomogeneity and torque in high temperature superconducting magnetic bearings