Secondary electron yields of carbon-coated and polished stainless steel
To increase the power throughput to a plasma of an existing lower hybrid waveguide, secondary electron production on the walls and subsequent electron multiplication must be reduced. Since carbon has a low secondary electron coefficient (delta), measurements were performed for several UHV compatible carbon coatings (Aquadag/sup X/, vacuum pyrolyzed Glyptal/sup X/, and lamp black deposited by electrophoresis) as a function of primary beam voltage (35 eV to 10 keV), surface roughness (60 through 600 grit mechanical polishing and electropolishing), coating thickness, and angle of incidence (theta). Also measured were uncoated stainless steel, Mo, Cu, Ti, TiC, and ATJ graphite. The yields were obtained by varying the sample bias and measuring the collected current while the samples were in the electron beam of a scanning Auger microprobe. This technique allows delta measurements of Auger characterized surfaces with < or =0.3 mm spatial resolution. Results show delta to have a typical energy dependence, with a peak occurring at 200 to 300 eV for normal incidence, and at higher energy for larger theta. In general, delta increases with theta more for smooth surfaces than for rough ones. Ninety percent of the secondary electrons have energies less than 25 eV. Some carbonized coating and surface treatment combinations give delta/sub max/ = 0.88 +- 0.01 for normal electron beam incidence: a reduction of almost 40% compared to untreated stainless steel.
- Research Organization:
- Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
- OSTI ID:
- 5576530
- Journal Information:
- J. Vac. Sci. Technol.; (United States), Vol. 20:4
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
GENERAL PHYSICS
70 PLASMA PHYSICS AND FUSION TECHNOLOGY
CARBON
DIP COATING
ELECTRODEPOSITION
COPPER
AUGER ELECTRON SPECTROSCOPY
ELECTRON EMISSION
ELECTRON MICROSCOPY
SECONDARY EMISSION
GRAPHITE
MOLYBDENUM
STAINLESS STEEL-304
BAKING
DIPPED COATINGS
ELECTRODEPOSITED COATINGS
ELECTROPOLISHING
MECHANICAL POLISHING
ROUGHNESS
TITANIUM
TITANIUM CARBIDES
ANGULAR DISTRIBUTION
ARGON IONS
DESORPTION
ELECTRON BEAMS
ELECTRON DENSITY
ENERGY SPECTRA
EV RANGE 10-100
EV RANGE 100-1000
FILMS
HIGH VACUUM
ION BEAMS
KEV RANGE 01-10
MEDIUM TEMPERATURE
OXIDATION
PLASMA HEATING
PLT DEVICES
SPUTTERING
SURFACE CLEANING
SURFACE CONTAMINATION
THICKNESS
ULTRAHIGH VACUUM
WALLS
WAVEGUIDES
ALLOYS
BEAMS
CARBIDES
CARBON COMPOUNDS
CHARGED PARTICLES
CHEMICAL REACTIONS
CHROMIUM ALLOYS
CHROMIUM STEELS
CHROMIUM-NICKEL STEELS
CLEANING
COATINGS
CONTAMINATION
CORROSION RESISTANT ALLOYS
DEPOSITION
DIMENSIONS
DISTRIBUTION
ELECTROLYSIS
ELECTRON SPECTROSCOPY
ELEMENTAL MINERALS
ELEMENTS
EMISSION
ENERGY RANGE
EV RANGE
HEAT RESISTANT MATERIALS
HEAT RESISTING ALLOYS
HEATING
IONS
IRON ALLOYS
IRON BASE ALLOYS
KEV RANGE
LEPTON BEAMS
LYSIS
MATERIALS
METALS
MICROSCOPY
MINERALS
NICKEL ALLOYS
NONMETALS
PARTICLE BEAMS
POLISHING
SPECTRA
SPECTROSCOPY
STAINLESS STEELS
STEELS
SURFACE COATING
SURFACE FINISHING
SURFACE PROPERTIES
THERMONUCLEAR REACTORS
TITANIUM COMPOUNDS
TOKAMAK TYPE REACTORS
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS
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