Cross-Field Propagation of Intense Neutralized Proton Beam near a Metal Plate

An intense neutralized proton beam (70 keV, 18 A/cm 2 , 200–300 ns) is injected into a magnetic field of 2 kG across the magnetic lines of force where a thin metal plate is placed with its surface parallel to the beam axis and perpendicular to the magnetic lines of force. It is found that the polarization electric field in the beam is shorted out by the plate only when the beam is in contact with the plate, and then the beam is deflected according to gyro-motions of the beam protons; otherwise, the polarization electric field is retained and the beam penetrates into the magnetic field without deflection by polarization drift.