Patent ID: 6037586
Filing Date: 2000-03-14
Classification: H01J

Abstract:
An apparatus for separating ions of a pulse by mass as said ions are guided along a course, each of the ions having a mass m within a range m.sub.min to m.sub.max, a same energy E, and a speed v given by v=(2E/m).sup.1/2, the ions passing a point P at a time T0, said apparatus comprising:guiding means for energy-isochronally guiding ions of a same mass along a closed circuit path having a course length L;insertion means having an insertion input for receiving the ions, an insertion output for inserting the ions deflected from the insertion input into the closed circuit path and a first control gate for either activating or deactivating the insertion means, the insertion input being located at a distance L1 from the point P;extraction means having an extraction input for receiving the ions guided along the closed circuit path, an extraction output for extracting the ions out of the closed circuit path and a first control gate for either activating or deactivating the extraction means, the extraction input being located at a course distance L2 from the insertion input; andcontrolling means having:a first output for sending a first control signal to the first control gate of the insertion means at a time T1, to activate the insertion means and consequently insert the ions present at the input thereof, T1 being chosen within limits defined by the following equation:T0.ltoreq.T1<T0+L1/v.sub.max, where v.sub.max =(2E/m.sub.min).sup.1/2 ;a second output for sending a second control signal to the first control gate of the insertion means to deactivate the insertion means at a time T2, T2 being chosen within limits defined by the following equation:T0+L1/v.sub.min <T2<T0+(L+L1)/v.sub.max, where v.sub.min =(2E/m.sub.max).sup.1/2 ;a third output for sending a third control signal to the first control gate of the extraction means at a time T3 to activate the extraction means and consequently extract the ions present at the input thereof, T3 being chosen within limits defined by the following equation:T0+L1/v.sub.min +(((n-1)L+L2)/v.sub.min)<T3<T0+L1/v.sub.max +(nL+L2)/v.sub.max,where n is a number of turns the pulsed ions travel within the closed circuit path; anda fourth output for sending a fourth control signal to the first control gate of the extraction means at a time T4 to deactivate the extraction means, T4 being chosen within limits defined by the following equation:T0+L1/v.sub.min +((nL+L2)/v.sub.min)<T4.