Thle monopole-a new instrument for measuring partial pressures

Design parameters appropriate to the construction of a monopole type mass spectrometer suitable for use as an ultra-high vacuum partial pressure analyzer are developed and elaborated. Performance results of an instrument built to these parameters are presented. Results indicate a usable mass range of 300 amu, with unit resolution over the whole range. Ultimate sensitivity is in the 10^-14 Torr partial pressure range.