Erosion/redeposition modeling and calculations for carbon

Conference · Fri Apr 01 04:00:00 EST 1988

OSTI ID:5574757

Brooks, J N; Brice, D K; Dewald, A B; McGrath, R T

Several key aspects of carbon erosion/redeposition in fusion devices have been examined. These include the effects of an oblique magnetic field geometry plasma sheath on ion impingement and sputtering, and the effect of surface hydrogen buildup on sputtering. The calculations use a version of the MEASTRI hydrogen implantation code and a cloud-in-cell type sheath code. Time dependent erosion calculations have been made for the TFTR bumper limiter, using the REDEP erosion/redeposition code with updated sheath and sputtering modes. The computed plasma carbon content during a TFTR limiter deconditioning'' run and for a supershot'' beam heating case is similar to measured values. The calculations predict that depletion of the near surface graphite hydrogen concentration enhances the self and hydrogen sputtering coefficients. This mechanism provides an explanation for the larger Z-effective values observed on TFTR immediately after limiter conditioning. 21 refs., 6 figs.

• Research Organization: Argonne National Lab., IL (USA); Sandia National Labs., Albuquerque, NM (USA); Georgia Inst. of Tech., Atlanta (USA)
• DOE Contract Number: W-31109-ENG-38; AC04-76DP00789
• OSTI ID: 5574757
• Report Number(s): ANL/FPP/TM-220; SAND--87-2868C; CONF-880512--5; ON: DE88010382
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700209* -- Fusion Power Plant Technology-- Component Development & Materials Testing
CARBON
CHARGED PARTICLES
DEPOSITION
ELEMENTAL MINERALS
ELEMENTS
EROSION
GRAPHITE
HYDROGEN IONS
IONS
LIMITERS
MINERALS
NONMETALS
PLASMA SHEATH
SPUTTERING
TFTR TOKAMAK
THERMONUCLEAR REACTORS
TOKAMAK TYPE REACTORS