HIGH FREQUENCY TUNNEL DEVICE STUDY,
Abstract
The work reported here is aimed at investigating the feasibility of achieving low-noise microwave amplification by using tunneling. As a result of a previous contract it has been concluded that a promising approach to achieving these objectives is the use of a thin-film cathode operating in conjunction with a microwave structure. At present it is possible to build tunnel cathodes that exhibit sufficient current density to permit their use in a traveling wave tube. However, the life of the cathodes in either continuous or pulsed operation is unsatisfactory. The efforts during this quarter have been aimed at solving the life problem. Measurements of the lifetimes of Al-Al2O3-Au tunnel cathodes have been obtained with pulse durations varying from 200 microseconds to 100 milliseconds, with duty cycles ranging from 0.001 to 0.1 and with sandwich current densities ranging from 0.5 amperes/ssq cm to 5 amperes/sq cm. As the testing proceeded the devices usually showed increased efficiencies for a time, then a rapid deterioration. At constant sandwich voltages, the sandwich currents generally remained approximately constant during the early stages of life, then gradually increased. The data showed some consistency when the emission current at constant voltage was plotted against the total charge passing through the device. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1964
- Accession Number
- AD0608037
Entities
People
- A. Starr
- S. R. Steele
Organizations
- RTX