MONTE-CARLO STUDIES OF HELIUM PUMPING AND SPUTTERING IN THE INTOR DIVERTOR
Monte Carlo calculations have been carried out for comparatively wide radial decay lengths of temperature and power in the plasma scrape-off layer in INTOR and these have been used to determine the spatial distribution of sputtering and redeposition at the wall of the divertor chamber by energetic neutral particles. The maximum erosion rate of a stainless steel wall was estimated to be about 8.5 mm/year (100 % operation). The same Monte Carlo treatment has been employed to demonstrate the effects of pump duct geometry upon pumping requirements. Within the limitations of the parameter space employed, the results show that the best performance is achieved if the entrance to the duct is restricted to a height of about 0.3 m. The vacuum pump speed required to exhaust 2 x 10**2o helium atom/s at 300 K is then about 350 m**3/s when the pumps are coupled to a downpipe of conductance 500 m**3/s.
Bibliographic Reference: WRITE TO CEC, D.G. XII-FUSION PROGRAMME, BRUXELLES (BELGIUM), MENTIONING NET REPORT EUR-XII-324/26, (FREE OF CHARGE).
Record Number: 1989123045000 / Last updated on: 1987-01-01
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