Accession Number : AD0680196

Title :   TECHNIQUE FOR LOCATING AND MAPPING THE SURFACE DENSITY OF MICRON-SIZED ASPERITIES USED AS COLD-CATHODE ELEMENTS.

Descriptive Note : Technical rept.,

Corporate Author : ARMY ELECTRONICS COMMAND FORT MONMOUTH N J

Personal Author(s) : Velasquez,Joseph

Report Date : DEC 1968

Pagination or Media Count : 12

Abstract : In order to understand the effects of field emission from asperities, it is necessary to make direct field-emission-current measurements of individual asperities. A procedural and evaluation technique has been refined using a modified Muller microscope with a motion resolution of 0.006 micrometers (60 A), which accurately determines the location and density of micron-sized asperities. The surface of a film of molybdenum metal containing asperities is scanned by means of a fine probe tip of positive potential with respect to the sample. The equipment is described and the technique used for locating individual asperities in order to give a field-emission contour of the metal surface is reviewed. Results on experimental samples are discussed; the criterion for the electric field strength of the asperities is discussed. (Author)

Descriptors :   (*CATHODES(ELECTRON TUBES), SURFACE ROUGHNESS), FIELD EMISSION, MEASUREMENT, DENSITY, METAL FILMS, MOLYBDENUM, SCANNING, ELECTRON MICROSCOPY

Subject Categories : Electrical and Electronic Equipment
      Test Facilities, Equipment and Methods

Distribution Statement : APPROVED FOR PUBLIC RELEASE