Ion formation at the boundary between a fast flow glow discharge ion source and a quadrupole mass spectrometer

摘要: An ion source is described for use in low power glow discharge mass spectrometry, using fast flowing argon as the gas, and attached to a quadrupole analyser. The flow carries plasma downstream onto an exit sampling cone which can be variably biased relative anode, enabling physical chemical properties of studied independently main ionisation region, cathode fall. parts were characterised by fixed probe potential measurements. Cone bias effects are consistent with contains large quantities high n Rydberg atoms both gas sputtered cathode. ionisable atom flux passing through aperture was measured directly, giving densities inside 1010–1011 cm−3. lower Rydbergs expected very much higher. H2 shown quench these states promote excitation their states. Field-ionisation or Auger deexcitation cell gives intensity beam, relatively uncontaminated higher species, such formed from gas.