| 摘要 |
PURPOSE: To provide an atmospheric pressure ionization mass spectrometer which is made compact so as to be used in purity control in each use point of gas for semiconductor equipment production, and capable of analyzing a small amount of a sample gas without decrease in detecting sensitivity. CONSTITUTION: A sample gas 1 introduced into an ion source 19 kept in almost atmospheric pressure is ionized by corona discharge conducted by applying high voltage to a needle electrode 3, ions produced are supplied to an analyzing part 20 made in high vacuum with a turbo-molecular pump 17 through a fine hole 6, focused with focusing lenses 8a, 8b, then introduced into a quadrupole mass spectrometer 9. The pore diameter of the fine hole 6 is made 10 micron or less, the amount of gas supplied is made 1.2cc/min. or less, and the exhaust speed of the vacuum pump is made 500 liter/sec. or less. Electrical field for accelerating ions is produced in the fine hole to increase the flowing amount of ions. |
