Double focusing mass spectrometer

Claim 2

A double focusing mass spectrometer comprising: an ion source for producing an ion beam; first inner and outer electrodes for producing a diverging electrostatic field so as to diverge the ions emitted from said source; second inner and outer electrodes for producing a converging electrostatic field so as to converge the ions delivered from said diverging electrostatic field at an intermediate focus point; means for producing a converging magnetic field so as to re-converge the ions once converged at said intermediate focus point by said converging electrostatic field; and means for detecting the ions converged by the magnetic field; such that said two electrostatic fields are connected with each other without substantial free space therebetween, and that said intermediate focus point of the ion beam is formed at a position adjacent to the ion exit boundary of said converging electrostatic field.

Claim 3

The double focusing mass spectrometer of claim 1 wherein the first and second inner electrodes are electrically connected with each other, and the first and second outer electrodes are electrically connected with each other.

Claim 4

The double focusing mass spectrometer of claim 1 wherein the radii of curvature of the central orbits of the ions in said two electrostatic fields are equal.

Claim 5

The double focusing mass spectrometer of claim 1, 2 or 3 further comprising a quadrupole lens means disposed between said intermediate focus point and said converging magnetic field for converging the ion beam in the Z direction.

Claim 6

A mass spectrometer comprising: an ion source for producing an ion beam; means for producing a diverging electrostatic field so as to diverge the ions emitted from said source; means for producing a converging electrostatic field so as to converge the ions delivered from said diverging electrostatic field at an intermediate focus point; means for producing a converging magnetic field so as to re-converge the ions once converged at said intermediate focus point and to satisfy the double focusing condition in combination with said means for producing electrostatic fields; and means for detecting the ions converged by the magnetic field; such that said two electrostatic fields are connected with each other without substantial free space therebetween, and that said intermediate focus point of the ion beam is formed at a position adjacent to the ion exit boundary of said converging electrostatic field.

Claim 7

A mass spectrometer comprising: an ion source for producing an ion beam; means for producing a diverging electrostatic field so as to diverge the ions emitted from said source; means for producing a converging electrostatic field so as to converge the ions delivered from said diverging electrostatic field at an intermediate focus point; means for producing a converging magnetic field so as to re-converge the ions once converged at said intermediate focus point and to satisfy the double focusing condition in combination with said means for producing electrostatic fields; and means for detecting the ions converged by the magnetic field; such that said two electrostatic fields are connected with each other without substantial free space therebetween, and that said intermediate focus point of the ion beam is formed at a position adjacent to the ion exit boundary of said converging electrostatic field.

Claim 8

The double focusing mass spectrometer of claim 5 wherein the radii of curvature of the central orbits of the ions in said two electrostatic fields are equal.

Claim 9

The double focusing mass spectrometer of claim 5 or 6 further comprising a quadrupole lens means disposed between said intermediate focus point and said converging magnetic field.