Patent ID: 7297960
Filing Date: 2007-11-20
Classification: H01J

Abstract:
1. A mass filter comprising: one or more electrodes associated with an entrance region of said mass filter, wherein, in use, one or more first voltage pulses are applied to said one or more electrodes in order to orthogonally accelerate at least some ions away from said one or more electrodes of said entrance region; and one or more ion mirrors for reflecting at least some ions which have been orthogonally accelerated away from said entrance region such that said reflected ions move generally towards an exit region of said mass filter disposed at a distance from said entrance region; wherein, in use, first ions having a desired mass or mass to charge ratio or having masses or mass to charge ratios within a first desired range are orthogonally decelerated or otherwise orthogonally retarded by one or more electric fields as said first ions approach said exit region of said mass filter.