Investigation of magnetic field errors in the supported spherator

The effect of slight asymmetry of the magnetic field in an azimuthally symmetric toroidal machine is investigated in the spherator by applying an additional uniform horizontal magnetic field. The azimuthal distribution of plasma loss across the magnetic field is varied by changing the direction and the strength of the additional horizontal magnetic field. Numerical calculations are carried out and possible initial field error is discussed by comparing the experimental results and an analytical calculation. By canceling the initial field error with the additional magnetic field, the particle loss becomes uniform in the azimuthal direction, but no significant change is observed in the confinement time in the argon afterglow plasma.