Staggered Closed PCM for Stable Rectangular Sheet Electron Beam Transport

Sheet electron beam transport under the magnetic field of a novel staggered closed periodic cusped magnet (PCM) has been investigated. In a staggered closed PCM, the horizontal and side magnets are placed in axially staggered positions and magnetized in the axial and transverse directions, respectively. Soft iron pole pieces are placed between two adjacent horizontal magnets of opposite polarity. Numerical analysis shows that effective root-mean-square value of the axial component of the magnetic field for the initial half cycle is higher for the proposed PCM than the conventional one by keeping the pole piece close to the magnets at first position. The magnetic period required to obtain desired peak value of the axial component of the magnetic field is shorter for the proposed PCM than for the conventional PCM for similar other parameters. Aforementioned advantages of the staggered closed PCM reduce the vertical displacement of the beam edge and stable transport of the sheet beam is possible through it. For a wide magnetic tunnel, required horizontal component of the magnetic field can be provided by extending the pole pieces between the horizontal magnets toward the beam surface and in the axial direction after the beam edges.