Evaluation of magnetic force distribution on a pair of superconducting bulk magnets

K. Yokoyama, T. Oka, K. Noto

Research output: Contribution to journalArticlepeer-review


We study the construction of superconducting permanent magnets by RE123 bulk materials and the investigation of these industrial applications such as a magnetic separation. A bulk magnet can generate strong magnetic fields exceeding 2 T, which is the limit of ordinary iron-cored electromagnets, in a compact device with a low running cost. A magnetic field distribution of the bulk magnet is a cone shape, and it contributes to an increase of magnetic force which is proportional to the product of a magnetic field and its gradient. It is important to evaluate magnetic force when the application of the bulk magnet is discussed. In this paper, two Gd123 bulk materials of 65 mm in diameter were magnetized using a pair of superconducting bulk magnet system and three-axis components of magnetic flux density (Bx, · By, and Bz) in an open space between the magnetic poles were scanned with pitch of 2 mm in each direction. From these measured data, the axial and radial components of magnetic force factor, Bz·dBz/dz and Br·dBr/dr, were calculated. At 10 mm gap, the Bz·dBz/dz value reached 180.6T2/m for a field of 2.33 T, which is comparable to Bz= 6.76T for a common 10T-100 mm ∅ superconducting magnet.

Original languageEnglish
Pages (from-to)1201-1206
Number of pages6
JournalPhysica C: Superconductivity and its applications
Issue number20
Publication statusPublished - 2010 Nov 1
Externally publishedYes


  • Magnetic field distribution
  • Magnetic force
  • Magnetic separation
  • Pulsed-field magnetization
  • Superconducting bulk magnet

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Energy Engineering and Power Technology
  • Electrical and Electronic Engineering


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