Ejection of ions from ion traps by combined electrical dipole and quadrupole fields

摘要: The invention relates to an improved method and apparatus for the mass-sequential ejection of ions from RF quadrupole ion trap by electrical alternating fields which are generated in addition quadrupolar storage field with different frequencies it. In contrast already known a pure dipole field, here essentially ejected field. leave through perforated end cap can be detected outside it conventional means. A weak undertakes only excitation secular oscillation at center, amplitude increasing linear manner stationary case. more intense further widening oscillations exponential growth amplitudes. is voltage between two caps, while caps on one hand ring electrode other. particular use very high masses ranging approximately 5,000 u 50,000 u. With same mass resolution, permits spectra recorded considerably quicker than hitherto fields.