Extraction system for charged secondary particles for use in a mass spectrometer or other charged particle device
AssigneeLuxembourg Institute of Science and Technology (List)
InventorDavid Dowsett
Life of this patent
Estimating the term…
Abstract
The invention is directed to mass spectrometer comprising an extraction system for secondary ions. The system comprises: an inner spherical deflecting sector; an outer spherical deflecting sector; a deflecting gap formed between the sectors; a housing in which the sectors are arranged. The deflecting sectors (42; 44) are biased at retarding gap (46). The system further comprises an exit disc electrode with an exit through hole centered about the exit axis, the intermediate electrode being biased at an intermediate voltage between the voltage of the housing and the average voltage of the sectors. The trajectories of the secondary ions become more parallel to the exit axis and become closer to the axis.
Claims30
A charged particle beam deflecting system, the charged particle beam deflecting system comprising:
- an inner spherical sector;
- an outer spherical sector;
- an entry for the charged particle beam;
- an exit passageway with an exit axis through which a deflected charged particle beam leaves the system;
- a deflecting gap which is formed between the spherical sectors and which communicates with the entry and with the exit passageway;
- an exit wall electrode with an exit opening facing the deflecting gap, the exit wall electrode comprising an exit wall potential;
- wherein the spherical sectors are biased at deflecting potentials in order to deflect the charged particle beam entering the deflecting gap by a given angle;
- an intermediate electrode with a plate shape and with an exit through hole centred about the exit axis,
- wherein the intermediate electrode is downstream the spherical sectors, and the intermediate electrode is biased at an intermediate potential between the exit wall potential and the average potential of the spherical sectors;
- and
- a housing in which the sectors are arranged, the housing forming the exit wall electrode.
A charged particle beam device comprising a charged particle deflecting system, the charged particle beam deflecting system comprising:
- an inner spherical sector;
- an outer spherical sector;
- an entry for the charged particle beam;
- an exit passageway with an exit axis through which a deflected charged particle beam leaves the system;
- a deflecting gap which is formed between the spherical sectors and which communicates with the entry and with the exit passageway;
- an exit wall electrode with an exit opening facing the deflecting gap, the exit wall electrode comprising an exit wall potential;
- wherein the spherical sectors are biased at deflecting potentials in order to deflect the charged particle beam entering the deflecting gap by a given angle;
- an intermediate electrode with a plate shape and with an exit through hole centred about the exit axis,
- wherein the intermediate electrode is downstream the spherical sectors, and the intermediate electrode is biased at an intermediate potential between the exit wall potential and the average potential of the spherical sectors;
- and
- a housing in which the sectors are arranged, the housing forming the exit wall electrode.
A gas flooding system comprising a charged particle beam deflecting system, the charged particle beam deflecting system comprising:
- an inner spherical sector;
- an outer spherical sector;
- an entry for the charged particle beam;
- an exit passageway with an exit axis through which a deflected charged particle beam leaves the system;
- a deflecting gap which is formed between the spherical sectors and which communicates with the entry and with the exit passageway;
- an exit wall electrode with an exit opening facing the deflecting gap, the exit wall electrode comprising an exit wall potential;
- wherein the spherical sectors are biased at deflecting potentials in order to deflect the charged particle beam entering the deflecting gap by a given angle;
- an intermediate electrode with a plate shape and with an exit through hole centred about the exit axis,
- wherein the intermediate electrode is downstream the spherical sectors, and the intermediate electrode is biased at an intermediate potential between the exit wall potential and the average potential of the spherical sectors;
- and
- a housing in which the sectors are arranged, the housing forming the exit wall electrode.
Dependencies are inferred from the claim text.