Field emitters for space application

We report on the development of a miniature ion trap mass spectrometer to b e deployed on European Space Agency's Rosetta Mission [Rosetta Comet Rendez vous Mission, ESA publication SC1(93)7 (1993)] to analyze the comet P46/Wir tanen. The mission is due to be launched in 2003 and following a long journ ey through space the comet rendezvous will take place in 2011 at a distance of approximately 465 million miles from earth. The instrument has been dev eloped on a stringent space budget of < 75 g in weight, 1 W maximum power c onsumption, and resolution down to <1 amu. Silicon field emitters have been successfully used as the electron source for producing ions by impact ioni zation. Mass spectra have been obtained for a number of,oases at pressures in the region of 10(-4) Torr. (C) 2001 American Vacuum Society.