The present paper describes a mass spectrometer operating on the following principle The same impulse is imparted initially to all ions with different em, which are then separated on the basis of their different energies. A sensitivity of 0.1 Atorr was attained at a resolution R mdelta m sub 50 30. Author
Trans. of Zeitschrift fuer Angewandte Physik (West Germany) v19 n4 p347-8 1965, by William J. Grimes.