Preventing contamination of specimens in spectroscopy vacuum vessel - by, pref. supersonic, gas curtain across potential contaminant path

摘要

Appts. for preventing contamination consists of a gas nozzle and gas extract aperture of an extract pipe. These are mounted inside the vauum vessel so that the gas curtain produced between the nozzle and extract aperture lies between the specimen and any possible sources of contamination. Pref., the gas jet from the nozzle is at supersonic speed. A series of nozzle-aperture systems, or an annular nozzle and annular aperture may be used to give all-around protection. Arrangement is used in electron spectroscopy for chemical analysis, for Auger electron spectroscopy, secondary ions mass spectroscopy, ions scattering spectroscopy etc. The vacuum around the specimen is not affected by the gas curtain.