A method for slowing and controlling a beam of charged particles includes the steps of superimposing at least one magnetic field on a mass and passing the beam through the mass and at least one magnetic field such that the beam and the mass slows but does not stop the particles. It also enables the home and foreign service providers to constrain and account for actual services provided based on a combination of the foreign and home operator policy. The pair of electrodes clamp the spots being welded while centering by acting a reaction force exerted when the electrodes clamp the spots to the resistance welding head.