To everyone screaming "this would not work": it would work (with right kind of fluorine rubber) as long as the lamp is attached to the pump. Thermionics (but not CRTs) don't actually need UHV, HV is good enough, so no copper conflat necessary. If you want to seal the tube off - then yes, the tube needs a proper seal and a getter. Afaik, the getter is there to counter slow outgassing of tube internals (virtual leaks) rather than any external leaks.