| 摘要 |
PURPOSE:To make it possible to obtain an accurate analysis value by a mass spectrometer, by generating a magnetic field around the tip of a skimmer, and making the electrons ionized in the plasma exercise a spiral movement to get a longer travel distance. CONSTITUTION:When a plasma 6 is drawn out in a nozzle 4, electrons ionized in the plasma are given a spiral movement at the top end of a skimmer 5 by the action of a magnetic field. Therefore, the travelling distance is extended at the top end of the skimmer 5, the probability of striking of the plasma to the skimmer 5 is actually increased intensively. Consequently, ionization in the plasma is increased, the discharge current between the plasma and the skimmer 5 is increased, and the discharge voltage is decreased finally. For such a reason, the discharge voltage in the nozzle 4 is reduced, and as a result, the ion mass can be detected accurately by a tetrode mass spectrometer.
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