Patent ID: 7576481

Claim:
A cathode for use in an x-ray tube comprising: a cup structure comprising: a cup base portion; a cup emission surface portion including an emission aperture, said cup emission surface portion including: a first ear portion; a second ear portion; a first side bridge formed between said first ear portion and said second ear portion; and a second side bridge formed between said first ear portion and said second ear portion, said first ear portion, said second ear portion, said first side bridge and said second side bridge together forming an essentially contiguous emission surface perimeter surrounding said emission aperture; a transverse coil chamber positioned within said cup base portion and below said cup emission surface portion comprising: a large transverse coil slot; a small transverse coil slot; and a separation pillar positioned between said large transverse coil slot and said small transverse coil slot; and in electro-discharge machining slot formed in said cup structure, said electro-discharge machining slot being separate from said transverse coil chamber and providing access to said transverse coil chamber such that said transverse coil chamber can be formed within said cup base portion and below said cup emission surface portion while maintaining said essentially contiguous emission surface perimeter; wherein said first side bridge and said second side bridge both extend above and across a portion of said transverse coil chamber.