Accession Number : ADA302403

Title :   A Novel Permanent Magnet Electron Beam Guide.

Descriptive Note : Technical rept.,

Corporate Author : ARMY RESEARCH LAB FORT MONMOUTH NJ

Personal Author(s) : Leupold, Herbert A. ; Potenziani, Ernest, II ; Myers, Dennis P. ; Furuno, David S.

PDF Url : ADA302403

Report Date : NOV 1995

Pagination or Media Count : 17

Abstract : A unique, lightweight, cladded permanent magnet structure which produces a constant, longitudinal magnetic field has been proposed previously. In this effort, a version of this structure appropriate for a conventional, linear beam electron tube was designed, constructed and evaluated. The permanent magnet system was designed to provide a 2.4 kOe axial guide field over a 23 cm distance. The design provides a volume of 3.5 cm diameter by 27 cm long for the microwave circuit, with radial penetrations for input rf, output rf and cooling. In order to minimize longitudinal flux at the position of the cathode, a shielded gun chamber is used.This chamber is clad with appropriate radially oriented magnets to prevent excessive flux leakage to the exterior and to insure field uniformity over the electron beam path. Figures depict the dependence of axial field magnitude on longitudinal position, and demonstrate excellent agreement between theory and measurement. The average field level measured is slightly higher than theoretical because of the switch to a higher remanence during construction. In addition, the field ripple near the collector end is due to penetrations in the magnet structure which were not modeled in the 2-D analyses.

Descriptors :   *ELECTRON TUBES, *MICROWAVE TUBES, *PERMANENT MAGNETS, LINEAR SYSTEMS, POSITION(LOCATION), MAGNETIC FIELDS, FLUX(RATE), MICROWAVE EQUIPMENT, COOLING, ELECTRON BEAMS, PENETRATION, RIPPLES, CIRCUITS, ELECTROMAGNETIC SHIELDING, RADIOFREQUENCY POWER.

Subject Categories : Electrical and Electronic Equipment
      Electricity and Magnetism

Distribution Statement : APPROVED FOR PUBLIC RELEASE