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US 8,477,908 B2Granted
System and method for beam focusing and control in an indirectly heated cathode
AssigneeGeneral Electric Company
InventorsYun Zou, Vance Scott Robinson, Louis Paul Inzinna, Kenneth Roger Conway, Sergio Lemaitre, Mark Alan Frontera, Xi Zhang, Vasile Bogdan Neculaes
Life of this patent
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Abstract
An indirectly heated cathode assembly is presented. The indirectly heated cathode assembly includes at least one electron source for generating a first electron beam, an emitter for producing a second electron beam when heated by the first electron beam and a focusing electrode for controlling, and directing the first electron beam towards the emitter.
Claims22
An indirectly heated cathode assembly, comprising:
- at least one electron source comprising a single cylindrical coil filament for generating a first electron beam;
- an emitter for producing a second electron beam when heated by the first electron beam;
- and
- a focusing electrode comprising at least one side wall, a horizontal wall, and a central wall coupled to the horizontal wall, wherein the single cylindrical coil filament surrounds the central wall, and wherein the side wall, the central wall and the horizontal wall are selectively positioned with resect to the single cylindrical coil filament so as to control an intensity distribution of the first electron beam impinging upon the emitter.
1 more element
An X-ray tube, comprising:
- a tube casing;
- an indirectly heated cathode assembly, comprising:
- at least one electron source comprising a single cylindrical coil filament for generating a first electron beam;
- an emitter for producing a second electron beam when heated by the first electron beam;
- a focusing electrode comprising at least one side wall, a horizontal wall, and a central wall coupled to the horizontal wall, wherein the single cylindrical coil filament surrounds the central wall, and wherein the side wall, the central wall and the horizontal wall are selectively positioned with respect to the single cylindrical coil filament so as to control an intensity distribution of the first electron beam impinging upon the emitter;
- and
- an anode for producing X-rays when impinged upon by the second electron beam.
4 more elements
A computed tomography system, comprising:
- a gantry;
- an X-ray tube coupled to the gantry, comprising:
- a tube casing;
- an indirectly heated cathode assembly, comprising:
- at least one electron source comprising a single cylindrical coil filament for generating a first electron beam;
- an emitter for producing a second electron beam when heated by the first electron beam;
- a focusing electrode comprising at least one side wall, a horizontal wall, and a central wall coupled to the horizontal wall, wherein the single cylindrical coil filament surrounds the central wall, and wherein the side wall, the central wall and the horizontal wall are selectively positioned with resect to the single cylindrical coil filament so as to control an intensity distribution of the first electron beam impinging upon the emitter;
- an anode for producing X-rays when impinged upon by the second electron beam;
- and
- an X-ray controller for providing power and timing signals to the X-ray tube.
7 more elements
In an indirectly heated cathode assembly having at least one electron source and an emitter, a method of controlling an electron beam, comprising:
- applying a first voltage to heat the at least one electron source comprising a single cylindrical coil filament to generate a first electron beam;
- applying a potential difference between the at least one electron source and the emitter to enhance kinetic energy of the first electron beam;
- directing and controlling an intensity distribution of the first electron beam towards the emitter using a focusing electrode comprising at least one side wall, a horizontal wall, and a central wall coupled to the horizontal wall, wherein the single cylindrical coil filament surrounds the central wall, and wherein the side wall, the central wall and the horizontal wall are selectively positioned with respect to the single cylindrical coil filament so as to control an intensity distribution of the first electron beam impinging upon the emitter;
- and
- generating a second electron beam by impinging the first electron beam on the emitter.
2 more elements
Dependencies are inferred from the claim text.