Patent ID: 8680463

Claim:
A mass spectrometer for radial amplitude assisted transfer (RAAT), said mass spectrometer comprising: an ion source; a first axial acceleration region for axially accelerating at least a portion of said ions from said ion source along a longitudinal axis of said mass spectrometer; at least one linear ion trap arranged to receive said ions from said ion source, said at least one linear ion trap comprising: an entrance region for receiving said ions therein; an exit region for transferring radially exited ions out of said at least one linear ion trap; at least one DC (direct current) electrode for applying a DC potential barrier to prevent unexcited ions from exiting said at least one linear ion trap; a radial excitation region between said entrance region and said exit region for selective radial excitation of said ions trapped in said at least one linear ion trap thereby producing said radially excited ions; a second axial acceleration region for further accelerating said radially excited ions along said longitudinal axis towards said exit region due to a pseudo-potential produced by a reduction in RF field strength, such that said a combined effect of forces on said radially excited ions due to said first axial acceleration region and said second axial acceleration region causes said radially excited ions to overcome said DC potential barrier while said unexcited ions which are not radially excited remain in said at least one linear ion trap; and a detection device for receiving and analyzing at least a portion of said radially excited ions that exit said at least one linear ion trap.