NI93O2 mass spectrometer for analysis of microquantity of inert and chemically active gases

To provide isotope analysis of inert gases at small isotopic ratios (to 10-9) and analysis of microquantities of inert and active gases a mass spectrometer has been developed which is characterized by increased values of the three main parameters: resolution, sensitivity and discrimination of adjacent lines. The design and the ion-optical system are described of a double-beam mass spectrometer with two successive separation stages for ions of the low-concentration component of the gas mixture under analysis (1st beam) and one separation stage for ions of the basic component (2nd beam). The first separation stage is a static magnetic analyzer with a deflection angle of 180 deg; it is common to the first and second beams. The second stage is the magnetic resonance analyzer in which ions are separated in accordance with the flight time. The mass analyzer chamber is evacuated to 5x10-10 mm Hg. The measuring range of the instrument is from 1 to 160 amu. The maximum resolution at a 50% level of the peak intensity is equal to 60,000. At the resolution of 10,000 the threshold of sensitivity for Ar constitutes 8x10-15 cm3