초록 ▼

In accordance with the invention, a microwave vacuum tube device, such as a traveling wave tube, is provided with an electron source comprising activated ultrafine diamonds. Applicants have discovered that ultrafine diamonds (5-1,000 nm diameter), when activated by heat treatment in a hydrogen plasm

In accordance with the invention, a microwave vacuum tube device, such as a traveling wave tube, is provided with an electron source comprising activated ultrafine diamonds. Applicants have discovered that ultrafine diamonds (5-1,000 nm diameter), when activated by heat treatment in a hydrogen plasma, become excellent room-temperature electron emitters capable of producing electron emission current density of at least 10 mA/cm.sup.2 at low electric fields of 10 V/micrometer. Sources using these diamonds provide electrons for microwave vacuum tubes at low voltage, low operating temperature and with fast turn-on characteristics. A multiple grid structure is described for providing high quality electron beams particularly useful for traveling wave tubes.

대표청구항 ▼

[ What is claimed:] [1.] In a microwave vacuum tube device comprising an evacuated tube having an input window for the introduction of a microwave input signal, a source of electrons, an interaction structure for enhancing interaction between said input signal and electrons from said source, and an

[ What is claimed:] [1.] In a microwave vacuum tube device comprising an evacuated tube having an input window for the introduction of a microwave input signal, a source of electrons, an interaction structure for enhancing interaction between said input signal and electrons from said source, and an output window for permitting the output of a microwave signal derived from said electrons, the improvement wherein: