A PROJECTION DIODE TECHNIQUE FOR THERMIONIC EMISSION FROM SINGLE CRYSTALS OF REFRACTORY METALS,
Abstract
An improved electron projection diode with an aluminum-backed fluorescent screen was developed to study thermionic emission from single crystal refractory metal filaments as a function of equilibration. Average thermionic constants phi R and A R may be obtained with the tube operating as a diode; point-by-point thermionic parameters may be obtained by photometric measurements. A modification of the projection diode allows the measurement of the elastically scattered primaries and high energy secondary electrons in a separate tube. Data for recrystallized molybdenum are given. These indicate (a) high work function is always associated with a terraced plateau, which develops on annealing. (b) The deviation of A R from 120 for Mo may be accounted for by patch effect, without recourse to a significant temperature coefficient of work function. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 08, 1964
- Accession Number
- AD0431332
Entities
People
- E. Coomes
- F. Gardner
- F. Girouard
- R. Anthony
Organizations
- University of Notre Dame