LIMITER FOR THE STELLARATOR W-VII-AS
In a first stage the Stellarator W VII-AS will work with two rail-type primary limiters placed horizontally at the top and bottom of the plasma at one toroidal position of the largest vertical plasma extension. The limiter front will be made from TiC coated graphite tiles inertially cooled during the pulse but actively between pulses (coolant water). The permissible surface thermal load is limited by the allowable TiC sublimation rate at pulse durations above approximately equal l s. For shorter pulses the thermal shock strength of the graphite becomes decisive. Assuming peak loads of 10 MW/m**2 integral loads of about 600-700 kW per limiter are permissible for e-folding lengths about 2 cm and external rotational transforms to <or= 0.5. These values are reduced drastically for larger and smaller of greater lambda values. For thermal loads exceeding the above limits the maximum surface temperature will become limited effectively only above 3000 K by sublimation cooling. For diagnostics an infrared thermography, thermopairs (tile backs) and a coolant calorimetry will be used. For a later stage two modular pump limiters are planned.
Bibliographic Reference: WRITE TO MAX-PLANCK-INSTITUT FUER PLASMAPHYSIK, 8046 GARCHING BEI MUENCHEN (GERMANY) MENTIONING REPORT IPP 2/276, 1985
Record Number: 1989125019200 / Last updated on: 1987-02-01
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