Analytical and experimental determination of the multipole cusp magnetic field in the VISIONI plasmatron

The VISIONI plasmatron is a plasma simulator dedicated to thermonuclear fusion material studies. The plasma is confined by means of a strong multipole cusp magnetic field produced by rectangular permanent samarium–cobalt magnets positioned just outside of the plasma chamber. The magnitude of this field as a function of the location in the plasma chamber is an important input for the ongoing plasma and material migration computer simulations for VISIONI. In this work the magnetic field in the VISIONI plasma chamber was calculated analytically. The calculated results were benchmarked and verified experimentally by Hall probe measurements. The analytical formulas are very convenient for use in different simulation codes.

► The magnetic field of one rectangular homogeneously magnetized permanent magnet was calculated analytically from Biot–Savart's law.
► The resulting equations were used to calculate the magnetic field inside the plasma chamber of the VISIONI plasmatron.
► Hall probe measurements of the magnetic field inside the plasma chamber of the VISIONI plasmatron benchmarked and verified the calculations.
► The analytical formulas are directly useable in simulation codes like ERO.