| 摘要 |
A field emission cathode comprises a metal holder provided by a wire pin 2 having a bend to define an apex, and an emitter in the form of a whisker 1 of metal carbide or metal boride fixed in a notch in the holder to project from the apex. Examples, with dimensions, are given in which the emitter whisker 1 is tantalum carbide or lanthanum hexaboride. The wire pin 2 may comprise tungsten and 20% rhenium. <IMAGE> |
