a magnetic field that mainly radial in {TAIL ~ area} around gas distributing system, over anode and having a minimum value in anode area; {HEAD ~ a radial magnetic field} is increasing its value along a central magnetic pole in a form of a protrusion till end of a protrusion, and from this protrusion to a discharge channel end side having both components of magnetic field, radial and axial in area over a central magnetic pole to a discharge channel exit 
a magnetic field that mainly radial in { TAIL ~ area } around gas distributing system , over anode and having a minimum value in anode area ; { HEAD ~ a radial magnetic field } is increasing its value along a central magnetic pole in a form of a protrusion till end of a protrusion , and from this protrusion to a discharge channel end side having both components of magnetic field , radial and axial in area over a central magnetic pole to a discharge channel exit
OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH