| 摘要 |
<p>An arrangement in mass spectrometers with a modulated molecular beam. The mass spectrometer comprises a modulation chamber (15) with a gas inlet (16) and with a connection (18) to a vacuum pump to produce a molecular beam (23). An ionization chamber (19), which contains the ion source (21) of the mass spectrometer and has a connection (20) to a vacuum pump, communicates with the modulation chamber through front and back openings (24, 25) in the path of the molecular beam (23). A chopper (28) to modulate the molecular beam is disposed in the modulation chamber in front of the front opening for the entry of the molecular beam into the ionization chamber. </p> |
