A Robust Cathode for Producing High-Power, High-Current Electron Beam
Abstract
Electron beams produced by the superemissive cathode of a back-lighted thyratron (BLT) or pseudospark are reported. The cathode is highly emissive, or superemissive during the conduction phase, producing a current density of > 10000 A/cm2 over an area of ~1 cm2. During this phase, electrons produced by the cathode are accelerated through the anode central hole, forming a beam that can be extracted. An electron beam of 120 A has been observed with an efficiency of 10%. The beam current increase with increasing applied voltages and decreasing gas pressure. A pulse forming network can transfer energy to an electron beam with a duration of the discharge pulse. The superemissive beam has energy of ~400 eV corresponding to the cathode sheath voltage. Beam extraction into a low pressure area ( <7 mTorr) was achieved by a differential pumping scheme with a guiding magnetic field. A uniform spatial profile of the beam current distribution is obtained after the beam propagation through a narrow dielectric tube.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1993
- Accession Number
- ADA638881
Entities
People
- G. Kirkman
- Martin A. Gundersen
- R. Liou
- Tian‐Jian Hsu
Organizations
- University of Southern California