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The internal surface of 50 cm long and 34 mm diameter Stainless Steel tubes were coated with TiV, TiVZr and TiVZrHf getter films using a cylindrical magnetron.
The NEG coated tubes were baked for 24 hours at various temperatures ranging from 150 C to 300 C. The TiVZr film had the lowest activation temperature which was found to be 180 C. The TiV film had the highest activation temperature of 250 C and the highest saturation coverage for CO of about 3 mono-layers. The evolution of surface chemical composition during the activation was determined by XPS and the functional properties were evaluated by pumping speed measurements. Film composition was determined by Rutherford back scattering and were found to be non homogenous in depth. Surface morphology was studied by SEM which revealed a columnar structure.
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