Periodic permanent magnet structures

Claim 2

A periodic permanent magnet structure comprising a plurality of hollow substantially spherical magnetic flux sources each of which produces a uniform high-field in its spherical central cavity, each sphere having an axial bore hole through the magnetic poles of the sphere, the spheres being placed tangent to each other with the axial bore holes of the spheres coaxially aligned with each other so as to form a continuous channel through the plurality of spheres.

Claim 3

A periodic permanent magnet structure as defined in claim 1 wherein the magnetic field orientations in the central cavities of the series of spheres are the same.

Claim 4

A periodic permanent magnet structure as defined in claim 2 wherein the spheres are of the same dimensions, and the magnetic field orientation in each axial bore hole is the reverse of that in each central cavity.

Claim 5

A periodic permanent magnet structure as defined in claim 3 wherein the shell thickness of each hollow sphere is equal to the cavity radius of the same.

Claim 6

A periodic permanent magnet structure as defined in claim 4 wherein said plurality of spheres comprises at least ten in number.

Claim 7

A periodic permanent magnet structure as defined in claim 5 wherein said axial bore holes are of a diameter up to one-fourth the diameter of said central cavity.

Claim 8

A periodic permanent magnet structure as defined in claim 1 wherein the magnetic field orientation in the central cavities of he series of spheres alternates in direction from sphere to sphere.

Claim 9

A periodic permanent magnet structure as defined in claim 7 wherein the spheres are of the same dimensions, and the magnetic field orientation in each axial bore hole is the reverse of that in each central cavity of a given sphere.

Claim 10

A periodic permanent magnet structure as defined in claim 8 wherein the shell thickness of each hollow sphere is twice, the cavity radius of the same.

Claim 11

A periodic permanent magnet structure as defined in claim 9 wherein said plurality of spheres comprises at least ten in number.

Claim 12

A periodic permanent magnet structure as defined in claim 10 wherein said axial bore holes are of a diameter up to one-fourth the diameter of the central cavity.

Claim 13

A periodic permanent magnet structure that provides a focusing magnetic field o alternating direction for use in traveling wave tubes comprising a series of hollow substantially spherical magnetic flux sources each of which produces a uniform high-field in its central cavity, each central cavity being substantially spherical, each spherical flux source having an axial bore hole through the magnetic poles of the same, each spherical flux source being azimuthally symmetrical in magnetization, the magnetic orientation in each spherical magnetic shell being substantially equal to twice the polar angle, each spherical source being comprised of a multiplicity of segments which extend in a tapered manner from the central cavity to the outer surface of the sphere, the spherical sources being placed tangent to each other with their axial bore holes coaxially aligned with each other to form a continuous channel through which a beam of electron can travel, the magnetic field orientations in the central cavities of the series of spheres being in the same axial direction, and the magnetic field orientation in the axial bore holes being in the opposite axial direction.

Claim 14

A periodic permanent magnet structure that provides a focusing magnetic field o alternating direction for use in traveling wave tubes comprising a series of hollow substantially spherical magnetic flux sources each of which produces a uniform high-field in its central cavity, each central cavity being substantially spherical, each spherical flux source having an axial bore hole through the magnetic poles of the same, each spherical flux source being azimuthally symmetrical in magnetization, the magnetic orientation in each spherical magnetic shell being substantially equal to twice the polar angle, each spherical source being comprised of a multiplicity of segments which extend in a tapered manner from the central cavity to the outer surface of the sphere, the spherical sources being placed tangent to each other with their axial bore holes coaxially aligned with each other to form a continuous channel through which a beam of electron can travel, the magnetic field orientations in the central cavities of the series of spheres being in the same axial direction, and the magnetic field orientation in the axial bore holes being in the opposite axial direction.