Title :
Surface studies and measurement of pumping characteristic of NEG coating (Ti-V-Zr)
Author :
Sharma, Ratnesh K. ; Sinha, Arun Kumar ; Jagannath ; Basak, D.C. ; Gadkari, S.C. ; Singh, M.R. ; Gupta, Suneet K.
Author_Institution :
Tech. Phys. Div., Bhabha Atomic Res. Centre, Mumbai, India
fDate :
Sept. 28 2014-Oct. 3 2014
Abstract :
NEGs (non evaporable getters) when coated as thin film on the inner wall of vacuum pipes or chamber play vital role in the evacuation of a sealed off system after heating it to activation temperature. It creates the uniformity of pressure between two long pipes where pumping is not possible at each and every part. Ternary coating of materials Ti, Zr and V has prepared on SS304L by DC-magnetron sputtering technique. These coatings was claimed to be very good in H2 adsorption which lead to achieve very low pressures of the order of 10-12-10-13 mbar, low SEY (Secondary Electron Yield) and Low photo desorption yield compared to bare SS surface. We have shown the morphology of surfaces of these coatings which play the principal role in adsorption of (H2, CO, CO2, H2O etc.) have been extensively studied by SEM/EDX technique. SEM showed the micron size thick film. Film thickness of micron level is useful for NEG to work for no. of atmospheric exposed cycles. Reduction of superficial surface oxide after heating it to different temperatures was main concern and studied by X-ray Photoelectron spectroscopic technique. It has also reported the pumping characteristic of the NEG coating.
Keywords :
X-ray chemical analysis; X-ray photoelectron spectra; adsorption; carbon compounds; getters; hydrogen; metallic thin films; photon stimulated desorption; reduction (chemical); scanning electron microscopy; secondary electron emission; sputter deposition; sputtered coatings; surface morphology; titanium alloys; vacuum pumps; vanadium alloys; water; zirconium alloys; CO; CO2; DC-magnetron sputtering; EDX; H2; H2O; NEG coating; SEM; SS304L; TiVZr; X-ray photoelectron spectroscopy; activation temperature; adsorption; atmospheric exposed cycles; chamber wall; film thickness; micron size thick film; nonevaporable getters; photodesorption yield; pressure uniformity; pumping characteristics; sealed off system evacuation; secondary electron yield; surface morphology; surface oxide reduction; ternary coating; thin film; vacuum pipes; Coatings; Films; Heating; Substrates; Surface treatment; Zirconium;
Conference_Titel :
Discharges and Electrical Insulation in Vacuum (ISDEIV), 2014 International Symposium on
Conference_Location :
Mumbai
Print_ISBN :
978-1-4799-6750-6
DOI :
10.1109/DEIV.2014.6961736