Travelling wave tubes
AssigneeEnglish Electric Valve Company Limited
InventorPeter Robert Davis
Life of this patent
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Abstract
A travelling wave tube having a periodic permanent magnetic focusing structure is provided with ferromagnetic plates having copper inserts which conduct heat away from the electron beam path and reduce the formation of hot spots.
Claims9
A fundamental coupled cavity travelling wave tube including a stack of apertured plates defining an electron beam path and assembled to provide a plurality of successive coupled cavities for the fundamental mode of operation in which a ferromagnetic plate is located at each end of each cavity and a plurality of non-magnetic plates are disposed therebetween, and a ferromagnetic pole piece is sandwiched between and contacted by each pair of ferromagnetic plates defining adjacent ends of adjacent cavities, and a periodic permanent magnetic focusing structure surrounding said cavities and consisting of a plurality of ring shaped magnets each of which is in magnetic contact with the pole pieces of an associated cavity, each pair of ferromagnetic plates projecting radially inwardly from the pole piece sandwiched therebetween to provide permanent fields extending into and surrounding the electron beam path of the tube, said ferromagnetic plates being provided with copper portions extending radially outwardly from adjacent said beam path to conduct heat away therefrom which is caused by electron beam impingement on such ferromagnetic plates.
In a fundamental coupled cavity travelling wave tube which defines an evacuated, axially extending electron beam path, a stack of centrally apertured plates whose central apertures are centered on said electron beam path and are defined at least by portions closely spaced from and cumulatively surrounding said electron beam path, certain spaced ones of said plates defining pole pieces and having peripheral margins projecting radially beyond the remaining plates, a series of ring shaped magnets surrounding said remaining plates and sandwiching the peripheral margins of said pole pieces therebetween, said plates defining successive cavities therebetween which are coupled for the fundamental mode of operation, said pole pieces and those particular plates immediately adjacent thereto being formed of ferromagnetic material while all other plates are formed of copper and said particular plates immediately adjacent said pole pieces having circular central apertures whereby said particular plates may be subjected to electron beam impingement tending to create hot spots, and copper insert means in said particular plates extending from said central apertures thereof into partial overlapping relation to said pole pieces.
Dependencies are inferred from the claim text.