Ion injection device for a time-of-flight mass spectrometer

A method to pulse ions into the flight tube of a time-of-flight mass spectrometer, comprising the steps of:

• providing a pusher cell with a pusher plate and a puller plate, both plates being slotted by slits into electrically insulated half plates;
• providing an RF voltage applied to the pusher half plates and, with reversed phase, to the puller half plates, the RF voltage generating a quadrupolar storage volume between the slits of the plates;
• providing a collision gas in the storage volume;
• filling the storage volume with ions;
• waiting to damp the ions into an elongate cloud;
• removing the RF voltage;
• inserting a delay period without any field;
• and
• applying a DC voltage between pusher plate and puller plate, thereby generating an accelerating field which accelerates the ions through the slit in the puller plate in the direction of the flight tube in a non-mass discriminating manner, wherein a correction voltage is applied to at least one correction electrode located outside the space between the pusher and puller plates in order to correct for distortions of the accelerating field near an adjacent one of the slits, the correction electrode comprising a lengthy protrusion running along the slit in the pusher plate.

A method to pulse ions into the flight tube of a time-of-flight mass spectrometer, comprising the steps of:

• providing a pusher cell with a pusher plate and a puller plate, both plates being slotted by slits into electrically insulated half plates;
• providing an RF voltage applied to the pusher half plates and, with reversed phase, to the puller half plates, the RF voltage generating a quadrupolar storage volume between the slits of the plates a center of which is located nearer to the slit in the pusher plate than to that in the puller plate;
• filling the storage volume with ions;
• removing the RF voltage;
• and
• applying a DC voltage between pusher plate and puller plate, thereby generating an accelerating field which accelerates the ions through the slit in the puller plate in the direction of the flight tube in a non-mass discriminating manner.

A method of hybridizing a time-of-flight analyzer to other ion optic devices, comprising the steps of:

• providing a pusher cell with a pusher plate and a puller plate, both plates being slotted by slits into electrically insulated half plates;
• providing an RF voltage applied to the pusher half plates and, with reversed phase, to the puller half plates, the RF voltage generating a quadrupolar storage volume between the slits of the plates;
• allowing a first group of ions to propagate from an upstream device, into an entrance end of the pusher cell, through the storage volume, and into a device at the exit end of the pusher cell;
• allowing a second group of ions to propagate into the storage volume,
• removing the RF voltage;
• and
• applying a DC voltage between pusher plate and puller plate, thereby generating an accelerating field which accelerates the ions through the slit in the puller plate in the direction of the flight tube in a non-mass discriminating manner, wherein a correction voltage is applied to at least one correction electrode located outside the space between the pusher and puller plates in order to correct for distortions of the accelerating field near an adjacent one of the slits, the correction electrode comprising a lengthy protrusion running along the slit in the pusher plate.