Accession Number : AD0431332


Title :   A PROJECTION DIODE TECHNIQUE FOR THERMIONIC EMISSION FROM SINGLE CRYSTALS OF REFRACTORY METALS,


Corporate Author : NOTRE DAME UNIV IND


Personal Author(s) : Gardner,F ; Girouard,F ; Anthony,R ; Coomes,E


Report Date : 08 Jan 1964


Pagination or Media Count : 46


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)


Descriptors :   *DIODES , THERMIONIC EMISSION , SYMMETRY(CRYSTALLOGRAPHY) , FLUORESCENT SCREENS , ALUMINUM , MEASUREMENT , ELASTIC SCATTERING , MOLYBDENUM , WORK FUNCTIONS , TEMPERATURE , PHOTOMETERS , CRYSTAL STRUCTURE , TUNGSTEN , IMAGE TUBES , CRYSTAL GROWTH , MICROSCOPY


Distribution Statement : APPROVED FOR PUBLIC RELEASE