Outward electron orbit extending to inward part of closed helical magnetic surfaces surrounded by shifted negative space potential

Outward electron orbits that extend to the inward part of a closed helical vacuum magnetic region are found in three-dimensional calculations, which take into account two experimental findings. The pitch angle of electrons in the stochastic magnetic region (SMR) is scattered considerably due to the presence of a shifted self-space potential φs. Eventually, the electron becomes a helically trapped particle, and starts an inward movement along one of the |Bmin| contours. Once penetrating into the helical magnetic region, the electron is never lost to the chamber wall, because the negative φs in the SMR acts as a potential barrier.