Deuterium pumping and erosion behavior of selected graphite materials under high flux plasma bombardment in PISCES
Deuterium plasma recycling and chemical erosion behavior of selected graphite materials have been investigated using the PISCES-A facility. These materials include: Pyro-graphite; 2D-graphite weave; 4D-graphite weave; and POCO-graphite. Deuterium plasma bombardment conditions are: fluxes around 7 /times/ 10/sup 17/ ions s/sup /minus/1/cm/sup /minus/2/; exposure time in the range from 10 to 100 s; bombarding energy of 300 eV; and graphite temperatures between 20 and 120/degree/C. To reduce deuterium plasma recycling, several approaches have been investigated. Erosion due to high-fluence helium plasma conditioning significantly increases the surface porosity of POCO-graphite and 4D-graphite weave whereas little change for 2D-graphite weave and Pyro-graphite. The increased pore openings and refreshed in-pore surface sites are found to reduce the deuterium plasma recycling and chemical erosion rates at transient stages. The steady state recycling rates for these graphite materials can be also correlated to the surface porosity. Surface topographical modification by machined-grooves noticeably reduces the steady state deuterium recycling rate and the impurity emission from the surface. These surface topography effects are attributed to co-deposition of remitted deuterium, chemically sputtered hydrocarbon and physically sputtered carbon under deuterium plasma bombardment. The co-deposited film is found to have a characteristic surface morphology with dendritic microstructures. 18 ref., 4 figs., 1 tab.
- Research Organization:
- California Univ., Los Angeles (USA). Inst. for Plasma and Fusion Research
- DOE Contract Number:
- AS03-84ER52104
- OSTI ID:
- 6988008
- Report Number(s):
- UCLA/PPG-1159; CONF-880512-8; ON: DE88012408
- Resource Relation:
- Conference: 8. international conference on plasma surface interactions in controlled fusion devices, Julich, F.R. Germany, 2 May 1988; Other Information: Portions of this document are illegible in microfiche products
- Country of Publication:
- United States
- Language:
- English
Similar Records
Erosion and redeposition behavior of selected net-candidate materials under high-flux hydrogen, deuterium plasma bombardment in PISCES
In situ spectroscopic measurements of erosion behavior of Tokamak Fusion Test Reactor-redeposited carbon materials under high-flux plasma bombardment in PISCES-A (Plasma Interactive Surface Component Experimental Station-A)
Related Subjects
36 MATERIALS SCIENCE
DEUTERIUM
RECYCLING
GRAPHITE
EROSION
DIVERTORS
EXPERIMENTAL DATA
FIRST WALL
FUEL PARTICLES
HELIUM
JET TOKAMAK
PLASMA
PLASMA GUNS
PUMPING
SPUTTERING
SURFACE PROPERTIES
TEXTOR TOKAMAK
TFTR TOKAMAK
TOKAMAK DEVICES
TRITIUM
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CARBON
CLOSED PLASMA DEVICES
DATA
ELEMENTAL MINERALS
ELEMENTS
FLUIDS
GASES
HYDROGEN ISOTOPES
INFORMATION
ISOTOPES
LIGHT NUCLEI
MINERALS
NONMETALS
NUCLEI
NUMERICAL DATA
ODD-EVEN NUCLEI
ODD-ODD NUCLEI
RADIOISOTOPES
RARE GASES
STABLE ISOTOPES
THERMONUCLEAR DEVICES
THERMONUCLEAR REACTOR WALLS
THERMONUCLEAR REACTORS
TOKAMAK TYPE REACTORS
YEARS LIVING RADIOISOTOPES
700205* - Fusion Power Plant Technology- Fuel
Heating
& Injection Systems
700201 - Fusion Power Plant Technology- Blanket Engineering
360604 - Materials- Corrosion
Erosion
& Degradation