Periodic permanent magnet electron beam focusing arrangement for traveling-wave tubes having plural interaction cavities in bore of each annular magnet

Claim 1

A DEVICE FOR FOCUSING A STREAM OF ELECTRONS ALONG A PREDETERMINED PATH AND FOR PROMOTING INTERACTION BETWEEN SAID STREAM OF ELECTRONS AND AN ELECTROMAGNETIC WAVE COMPRISING: A PLURALITY OF AXIALLY ALIGNED ESSENTIALLY ANNULAR PERMANENT MAGNETS MAGNETIZED AXIALLY AND ARRANGED WITH LIKE POLES OF ADJACENT MAGNETS CONFRONTING ONE ANOTHER, A PLURALITY OF DISC-LIKE FERROGMAGNETIC POLE PIECES INTERPOSED BETWEEN AND ABUTTING ADJACENT MAGNETS, SAID POLE PIECES PROJECTING RADIALLY INWARDLY OF SAID MAGNETS AND DEFINING ALIGNED APERTURES IN THEIR CENTRAL REGIONS, EACH SAID POLE PIECE FURTHER DEFINING A COUPLING HOLE IN A REGION RADIALLY OUTWARDLY OF ITS CENTRAIL REGION, MEANS DISPOSED RADIALLY INWARDLY OF EACH OF SAID MAGNETS FOR PROVIDING IN THE SPACE DEFINED BY THE INNER CIRCUMFERENTIAL SURFACE OF SAID MAGNET A PLURALITY OF INTERACTION CAVITIES OF SUBSTANTIALLY EQUAL AXIAL EXTENT SUCCESSIVELY DISPOSED ALONG SAID PREDETERMINED PATH, SAID MEANS HAVING AN ANNULAR PORTION OF AN OUTER DIAMETER ESSENTIALLY EQUAL TO THE INNER DIAMETER OF SAID MAGNET AND AT LEAST ONE PLATE-LIKE PORTION PROJECTING RADIALLY INWARDLY OF SAID ANNULAR PORTION IN A PLANE SUBSTANTIALLY PERPENDICULAR TO SAID PREDETERMINED PATH, EACH SAID PLATELIKE PORTION DEFINING AN APERTURE IN ITS CENTRAL REGION WHICH IS ALIGNED WITH SAID ALIGNED APERTURES OF SAID POLE PIECES TO PROVIDE A PASSAGE FOR SAID STREAM OF ELECTRODES EACH SAID PLATE-LIKE PORTION FURTHER DEFINING A COUPLING HOLE IN A REGION RADIALLY OUTWARDLY OF ITS CENTRAL REGION FOR INTERCONNECTING ADJACENT INTERACTION CAVITIES WHEREBY SAID ELECTROMAGNETIC WAVE MAY PROPAGATE THROUGH SAID COUPLING HOLES IN SAID PLATE-LIKE PORTIONS AND IN SAID POLE PIECES, EACH OF SAID PLATE-LIKE PORTIONS AND EACH OF SAID POLE PIECES DEFINING ADJACENT ITS CENTRAL APERTURE A TUBULAR PORTION WHICH EXTENDS ALONG SAID PREDETERMINED PATH, AND AT LEAST SAID TUBULAR PORTION OF EACH SAID MEANS BEING OF FERROMAGNETIC MATERIAL WITH THE REMAINDER OF SAID MEANS BEING OF ELECTRICALLY CONDUCTIVE NONMAGNETIC MATERIAL.

Claim 2

A DEVICE FOR FOCUSING A STREAM OF ELECTRONS ALONG A PREDETERMINED PATH AND FOR PROMOTING INTERACTION BETWEEN SAID STREAM OF ELECTRONS AND AN ELECTROMAGNETIC WAVE COMPRISING: A PLURALITY OF AXIALLY ALIGNED ESSENTIALLY ANNULAR PERMANENT MAGNETS MAGNETIZED AXIALLY AND ARRANGED WITH LIKE POLES OF ADJACENT MAGNETS CONFRONTING ONE ANOTHER, A PLURALITY OF DISC-LIKE FERROGMAGNETIC POLE PIECES INTERPOSED BETWEEN AND ABUTTING ADJACENT MAGNETS, SAID POLE PIECES PROJECTING RADIALLY INWARDLY OF SAID MAGNETS AND DEFINING ALIGNED APERTURES IN THEIR CENTRAL REGIONS, EACH SAID POLE PIECE FURTHER DEFINING A COUPLING HOLE IN A REGION RADIALLY OUTWARDLY OF ITS CENTRAIL REGION, MEANS DISPOSED RADIALLY INWARDLY OF EACH OF SAID MAGNETS FOR PROVIDING IN THE SPACE DEFINED BY THE INNER CIRCUMFERENTIAL SURFACE OF SAID MAGNET A PLURALITY OF INTERACTION CAVITIES OF SUBSTANTIALLY EQUAL AXIAL EXTENT SUCCESSIVELY DISPOSED ALONG SAID PREDETERMINED PATH, SAID MEANS HAVING AN ANNULAR PORTION OF AN OUTER DIAMETER ESSENTIALLY EQUAL TO THE INNER DIAMETER OF SAID MAGNET AND AT LEAST ONE PLATE-LIKE PORTION PROJECTING RADIALLY INWARDLY OF SAID ANNULAR PORTION IN A PLANE SUBSTANTIALLY PERPENDICULAR TO SAID PREDETERMINED PATH, EACH SAID PLATELIKE PORTION DEFINING AN APERTURE IN ITS CENTRAL REGION WHICH IS ALIGNED WITH SAID ALIGNED APERTURES OF SAID POLE PIECES TO PROVIDE A PASSAGE FOR SAID STREAM OF ELECTRODES EACH SAID PLATE-LIKE PORTION FURTHER DEFINING A COUPLING HOLE IN A REGION RADIALLY OUTWARDLY OF ITS CENTRAL REGION FOR INTERCONNECTING ADJACENT INTERACTION CAVITIES WHEREBY SAID ELECTROMAGNETIC WAVE MAY PROPAGATE THROUGH SAID COUPLING HOLES IN SAID PLATE-LIKE PORTIONS AND IN SAID POLE PIECES, EACH OF SAID PLATE-LIKE PORTIONS AND EACH OF SAID POLE PIECES DEFINING ADJACENT ITS CENTRAL APERTURE A TUBULAR PORTION WHICH EXTENDS ALONG SAID PREDETERMINED PATH, AND AT LEAST SAID TUBULAR PORTION OF EACH SAID MEANS BEING OF FERROMAGNETIC MATERIAL WITH THE REMAINDER OF SAID MEANS BEING OF ELECTRICALLY CONDUCTIVE NONMAGNETIC MATERIAL.