MANUFACTURING AND TESTING OF ACTIVELY COOLED TEST LIMITERS FOR TEXTORMADE OF THE BRAZED JOINT SEPCARB-N11 TZM/

To investigate the erosion and redepositon phenomena of fusion-related materials under stationary conditions, actively cooled test limiters were developed for TEXTOR (Tokamak Experiment for Technology Orientate d Research). They allow experiments under stationary conditions within the plasma pulse length of 10 s. Heat loads of typically 10 MW m(-2) are removed by pressurised water: volume flow is 10 m(3) h(-1), pressu re 15 bar and the minimum coefficient of heat transfer is about 75000 W m(-2) :K. Prototype limiters were built as brazed composites of a C/ C material (SEPCARB-N11) and a TZM substrate. The samples were success fully tested in screening tests in the ion beam facility MARION (Mater ial Research Ion Beam Test Facility) with hydrogen beams, Maximum hear loads of up to 22 MW m(-2) were applied without any failure of the co oling system. Steady slate of the surface temperature was measured wit hin 5 s. An advanced brazing technique enabled the joining of hemisphe rically shaped C/C: shells to a TZM heat sink without failure. An opti mised test limiter was tested in TEXTOR. Analytical and numerical mode ls describing the effects of the heal load distribution, spatial tempe ratures and stresses were experimentally verified. (C) 1998 Elsevier S cience S.A.