An analysis of the use of magnetic source tomography to measure the spatial distribution of electric current during vacuum arc remelting

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Magnetic source tomography is explored to analyse the distribution of electric current during vacuum arc remelting (VAR). The goal is to use sensors outside the process to deduce the behaviour within. VAR systems having non-axisymmetric distributions of arc current were modelled using a commercial finite element electromagnetic code (Opera 3d), and a database was created from the resulting patterns of magnetic flux predicted to occur outside the crucible. A reconstruction algorithm was developed using constrained nonlinear optimization to estimate the arc current distribution within the process from the magnetic field data outside. The capabilities of this algorithm were studied, and it was found that given sufficiently low noise in the measurement data it was possible to accurately deduce important features of the spatial distribution of the arc current.


Original languageEnglish
Article number045701
Number of pages1
JournalMeasurement Science and Technology
Issue number4
Early online date10 Feb 2009
Publication statusPublished - 1 Apr 2009


  • optimization methods, electromagnetic tomography, discharge in vacuum