ELECTROMAGNETIC WAVE-CHARGE INTERACTION IN CROSSED FIELDS.
Abstract
The construction of a crossed-field amplifier which will incorporate the results of our noise studies is in progress. Efforts have recently been concentrated on the measurement of the omega-beta relation of a flattened-helix circuit. The paraxial crossed-field gun design method developed by R. A. Rao is being carried on to obtain designs for magnetically shielded guns. It has been found that in the case of a nonuniform magnetic field the paraxial ray equation as presented by R. A. Rao must be modified to include a term involving the first derivative of B with respect to distance normal to the beam trajectory. The possibility of obtaining photo emission from the cathode of a crossed-field microwave vacuum tube is studied. Photocurrents of 240 mA have been obtained using a SbCs coated photocathode with a 2.1 watt light beam focused to an area of 40 sq mm. An argon laser was used in the experiments. It appears that photoelectric emission, but not thermionic emission, can be stimulated in interesting amounts by sources having power levels of a few watts. An experimental and theoretical evaluation of the crossed-field acoustic-wave amplifier is being conducted. The useful frequency range is being determined for this device using InSb, the most suitable material available at present. Electromagnetic and space-charge waves in solid conductors are being studied in order to determine if there are microwave device applications. During this quarter an instability theorem was derived which states the necessary conditions for amplification in bulk conductors. It shows that transverse rf fields are necessary for amplification in an electron-hole plasma. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 1968
- Accession Number
- AD0668690
Entities
People
- C. W. Turner
- K. A. Fox
- Michael A. Meÿer
- S. Swierkowski
- T. Van Duzer
Organizations
- University of California, Berkeley