Angled Flat Emitter For High Power Cathode With Electrostatic Emission Control

An X-ray tube comprising:

• a cathode assembly comprising at least two emitters disposed at an angle relative to one another, each emitter configured to generate an electron beam;
• a focusing electrode adjacent the cathode assembly for focusing the electron beams;
• an extraction electrode spaced from the focusing electrode opposite the cathode assembly for controlling the intensity of the electron beams;
• a magnetic assembly spaced from the extraction electrode opposite the focusing electrode;
• and
• a target spaced from the magnetic assembly opposite the extraction electrode.

A method for focusing an electron beam emitted from an X-ray tube, the method comprising the steps of:

• providing an X-ray tube including a cathode assembly in which is disposed at least two emitters disposed at an angle relative to one another, each emitter configured to generate an electron beam therefrom, a focusing electrode adjacent the cathode assembly, an extraction electrode spaced from the focusing electrode opposite the cathode assembly, a magnetic assembly spaced from the extraction electrode opposite the focusing electrode and a target spaced from the magnetic assembly opposite the extraction electrode capable of generating X-rays when impinged upon by the electron beams;
• passing an emission current through at least one of the emitters to generate an electron beam;
• and
• passing a focusing current through the magnetic assembly to focus the electron beam onto the target.

A computed tomography system, comprising;

• a gantry;
• an X-ray tube coupled to the gantry, the X-ray tube including a cathode assembly comprising at least two emitters for generating an electron beam, the emitters disposed therein at an angle with respect to one another, a focusing electrode for focusing the electron beam;
• an extraction electrode which controls the intensity of the electron beam;
• a target for generating X-rays when impinged upon by the electron beam;
• a magnetic assembly located between the cathode assembly and the target for focusing the electron beam towards the target;
• an X-ray controller for providing power and timing signals to the X-ray tube;
• and one or more detector elements for detecting attenuated X-ray beam from an imaging object.