HERMETIC SEALING OFF THE STAINLESS-STEEL PUMPING TUBE

Manufacturing special ampoules for investigations of alkali metal vapo urs we came across some technologically very demanding operations as a re shaping of approx. 0,008 mm thick stainless steel (SS) membrane, fi xing it on the massive ring, hermetic sealing-off by pinching the SS t hick-wall tube during evacuation, ii? such a way that in the removed a mpoule vacuum remains unspoiled etc. The last procedure, which is an o rdinary technique for Cu- and Al-tubes, was adapted and successfully p erformed on SS-connection. instead of cold welding we used the combina tion of cold and hot technique. We have studied the geometry of squeez ed tube, the weld formation from melted steel at different dimension a nd pressure conditions, also tightness and degassing have been measure d. The article discusses technology and some testing results that, acc ording to our knowledge, has not been described yet.