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 are biased at retarding potentials in order to reduce the energy of the ion beam entering the deflecting gap. The system further comprises an exit disc electrode which is biased at the midvoltage of the average voltage of the sectors, and two side plates both facing the spherical sectors, the side plates being biased in order to create an electrostatic field perpendicular to the exit axis.
Claims32
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;
- the spherical sectors being biased at deflecting potentials in order to deflect the charged particle beam entering the deflecting gap by a given angle;
- wherein the system further comprises:
- an intermediate electrode with a plate shape and with an exit through hole, the intermediate electrode being arranged between the deflecting gap and the exit wall electrode;
- and
- two side plates both facing the spherical sectors, the side plates being biased in order to create an electrostatic field perpendicular to the exit axis.
A charged particle beam device 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;
- the spherical sectors being biased at deflecting potentials in order to deflect the charged particle beam entering the deflecting gap by a given angle;
- wherein the system further comprises:
- an intermediate electrode with a plate shape and with an exit through hole, the intermediate electrode being arranged between the deflecting gap and the exit wall electrode;
- and two side plates both facing the spherical sectors, the side plates being biased in order to create an electrostatic field perpendicular to the exit axis.
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;
- the spherical sectors being biased at deflecting potentials in order to deflect the charged particle beam entering the deflecting gap by a given angle;
- wherein the system further comprises:
- an intermediate electrode with a plate shape and with an exit through hole, the intermediate electrode being arranged between the deflecting gap and the exit wall electrode;
- and
- two side plates both facing the spherical sectors, the side plates being biased in order to create an electrostatic field perpendicular to the exit axis.
Dependencies are inferred from the claim text.