X-z geometry periodic permanent magnet focusing system

An X-Z focusing system for focusing an electron beam, comprising:

• a tube having a plurality of magnetic polepieces interposed by non-magnetic spacers, an axially disposed beam tunnel permitting projection of said electron beam therethrough, and a thermal surface disposed on at least one side of said tube;
• and
• means for inducing a magnetic field in said tube having lines of flux which flow through said polepieces in a first general direction and which jumps through said beam tunnel to focus said beam, said including means comprising permanent magnets disposed externally of said circuit and mechanically coupled to said polepieces, said magnets providing said magnetic field;
• wherein, heat formed within said tube flows through said spacers to said thermal surface in a second general direction which is non-coincident with said first direction, and at least three of said polepieces are coupled by individual ones of said permanent magnets, and polarity of said permanent magnets alternates with each of said coupled polepieces.

A focusing system for a plurality of electron beams, the system comprising:

• at least two tubes formed from a plurality of magnetic polepieces interposed by non-magnetic spacers, said tubes having axially disposed beam tunnels permitting projection of said electron beams therethrough and surfaces disposed on two sides of each of said tubes;
• and
• a means for inducing a magnetic field in said tubes having lines of flux which flow through said polepieces in a first general direction and which jumps through said beam tunnel to focus said beam, heat formed within said tubes flowing through said spacers to said planar surfaces in a second general direction which is non-coincident with said first direction;
• wherein, said tubes are mechanically joined together with each adjacent pair of said tubes sharing a common heat sink therebetween, each of said tubes providing focusing for an associated one of said electron beams.

An electron beam focusing system, comprising:

• a tube comprising a plurality of magnetic polepieces interposed by non-magnetic spacers, said tube having an axially disposed beam tunnel permitting projection of an electron beam therethrough;
• and
• means for inducing a magnetic field in said tube to focus said beam, said magnetic field having lines of flux through said polepieces along a magnetic axis, and heat generated within said tube having lines of flux through said spacers along a thermal axis;
• wherein said magnetic axis is substantially perpendicular to said thermal axis.

An electron beam focusing system, comprising:

• a tube formed from a plurality of magnetic polepieces interposed by non-magnetic spacers, said tube having an axially disposed beam tunnel offset within said tube permitting projection of an electron beam therethrough;
• thermal surfaces disposed on a plurality of sides of said tube, said surfaces permitting the attachment of heat sinks thereto, heat generated within said tube flowing through said spacers to said thermal surfaces;
• and
• a means for inducing a magnetic field in said tube to focus said beam, said magnetic field having lines of flux through said polepieces which are non-coincident with the direction of said heat flow.