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  • Ekstremni visoki vakuum : novi pogledi
    Nemanič, Vincenc
    During the last forty years, a great progress was noticed on the whole field of vacuum technique. To reach and accurately measure a pressure in te UHV region became obvious in many branches, while ... the preparation of UHV is more or less just a routine. The situation was not the same in the range of extremely high vacuum (EHV). The lowest record from tthe early sixties was matched again few years ago. EHV is still interested and reserved for the surface science, particle physics and the vacuum meteorology. In the present paper, some results of the studies of hydrogen outgassing are presented. The recombination limited model was used to be comfirmed as a limiting phase of hydrogen outgassing. Ten equal cells were made from steinless steel of thickness of 0,15 mm, volume 0,16 l and the inner surface area of 450cm2. During a controlled heat treatment cycle, they were pumped to UHV region (typically 5.10[sup](-8) mbar), when the pumping tube was sealed-off. Even if the temperature and the duration of a bake out were relatively short the initial outgassing rate was typically below q[sub](out) = 2.10[sup](-14) mbar.l/cm2s. In seven cells, the presure and the pressure rise slope were measured again after some thousand hours. The total pressure was measured again and the composition of residual atmosphere was determined afterwards. Both results confirm the applied model. It is evident, that by applying the minimum thickness of the chamber wall, achieving and meintenance of UHV and EHV stainless steel chambers can be made cheaper and simplified.
    Vir: Vakuumist : glasilo Društva za vakuumsko tehniko Slovenije. - ISSN 0351-9716 (Letn. 19, št. 2, jun. 1999, str. 4-8)
    Vrsta gradiva - članek, sestavni del
    Leto - 1999
    Jezik - slovenski
    COBISS.SI-ID - 15263783

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