The Researchers discovered that a localized glow appeared close to the cathode surface when exposed to the magnetic dipole field generated by a bar magnet. As described in their paper, this localization is the result of enhanced degree of ionization due to confinement of electrons in the magnetic field close to the surface of negatively charged cathode. The Researchers also observed that the glow region’s intensity increased when they increased the strength of the magnetic field.  

Work in this field is traditionally performed by keeping a permanent magnet within a plasma chamber which means there is no other means to change the field line structure or field strength. The Authors of this paper could change the magnet’s position and alter the strength of the magnetic field by placing the bar magnet on the outside of the plasma chamber.