CHARACTERIZATION OF HYPERVELOCITY IMPACT CRATERS ON CHEMICAL-VAPOR-DEPOSITED DIAMOND AND DIAMOND-LIKE CARBON-FILMS

Microwave plasma chemical vapour-deposited (CVD) process has been used to grow polycrystalline diamond films over silicon substrates. Diamon d-like carbon (DLC) thin films were grown over silicon substrates usin g a microwave plasma disc reactor. Reactant gases of CH4 and H-2 were used in both CVD processes. Some preliminary feasibility tests were pe rformed on the possible applicability of diamond and diamond-like carb on thin films for space-protective applications against artificially s imulated electrically actuated plasma drag hypervelocity impact of oli vine particles. As-deposited films were analysed by Raman for their ch emical nature. The morphology and dimensions of hypervelocity impact c raters in diamond and DLC films was also studied by scanning electron microscopy (SEM) and optical microscopy. The velocity of debris partic les was determined by high-speed photography using a streak camera. Th e size of the impact particles was determined by measuring the size of the holes formed in the mylar sheet mounted just above the target dia mond and DLC film;silicon and coordinates of the impact sites were det ermined using the same apparatus.