Tandem time-of-flight mass spectrometer
A tandem mass spectrometer includes a linear time-of-flight mass analyzer and curved field reflectron mass analyzer. The curved-field reflectron mass analyzer is disposed at an end of the linear time-of-flight mass analyzer such that ions having a plurality of ion masses formed in the linear time-of-flight analyzer such that ions having a plurality of ion masses formed in the linear time-of-flight analyzer enter the curved-field reflectron mass analyzer. The tandem mass spectrometer also includes a mass selection gate disposed between the time-of-flight mass analyzer and the curved-field reflectron mass analyzer. The mass selection gate selects an ion mass from the plurality of ion masses. Furthermore, the tandem mass spectrometer also includes a dissociating component located in a path of the ions formed in the linear time-of-flight analyzer. The dissociating component causes dissociation of the ions into a plurality of ion fragments.
1. A tandem mass spectrometer, comprising:
a linear time-of-flight mass analyzer having a field-free drift region;
a curved-field reflectron mass analyzer disposed at an end of the linear time-of-flight mass analyzer such that ions having a plurality of ion masses when formed in the linear time-of-flight analyzer enter the curved-field reflectron mass analyzer,
wherein the curved-field reflectron comprises a drift region and a non-linear field region defined by a series of lens elements;
a mass selection gate disposed between the linear time-of-flight mass analyzer and the curved-field reflectron mass analyzer, the mass selection gate being located in the field-free drift region, upstream of the non-linear field region, said mass selection gate operable to select an ion mass from said plurality of ion masses; and
a dissociating component located in a path of the ions formed in the linear time-of-flight analyzer,
wherein said dissociating component causes dissociation of said ions into a plurality of ion fragments.
2. The tandem mass spectrometer according to claim 1 ,
wherein the linear time-of-flight analyzer comprises an ion source.
3. The tandem mass spectrometer according to claim 2 ,
wherein said ion source comprises a sample plate and a source of ionizing energy.
4. The tandem mass spectrometer according to claim 3 ,
wherein said ion source further comprises an extraction electrode disposed proximate said sample plate.
5. The tandem mass spectrometer according to claim 3 ,
wherein said source of ionizing energy is a laser.
6. The tandem mass spectrometer according to claim 3 ,
wherein said source of ionizing energy is an electron beam source.
7. The tandem mass spectrometer according to claim 3 ,
wherein said source of ionizing energy is an energetic ion beam.
8. The tandem mass spectrometer according to claim 3 ,
wherein said source of ionizing energy is an energetic atomic beam.
9. The tandem mass spectrometer according to claim 3 ,
wherein said source of ionizing energy is a radio-frequency voltage source.
10. The tandem mass spectrometer according to claim 4 ,
wherein said extraction electrode includes a grid electrode held at a voltage relative to said sample plate such that ions formed in said sample plate are extracted from said sample plate.
11. The tandem mass spectrometer according to claim 3 ,
wherein said sample plate is held at a sample voltage.
12. The tandem mass spectrometer according to claim 11 ,
wherein said sample voltage is a voltage with a magnitude between about 1 kilovolt to 50 kilovolts.
13. The tandem mass spectrometer according to claim 11 ,
wherein said sample voltage is pulsed to focus ions formed in said ion source.
14. The tandem mass spectrometer according to claim 4 ,
wherein said extraction electrode is held at an extraction voltage, and said extraction voltage is a voltage with a magnitude between about 1 kilovolt to 50 kilovolts.
15. The tandem mass spectrometer according to claim 1 ,
wherein the non-linear field region in the curved-field reflectron is configured to focus at least a major portion of the ion fragments formed at any point along a flight portion of the tandem mass spectrometer, the flight portion including the drift region in the linear time-of-flight mass analyzer and the drift region in the curved-field reflectron mass analyzer.
16. The tandem mass spectrometer according to claim 1 ,
wherein the non-linear field region in the curved-field reflectron is configured to focus at least a major portion of a mass range of the ion fragments without having to scan or step the electrical voltage potentials in the curved-field reflectron to accommodate an energy bandwidth of the curved-field reflectron.
17. The tandem mass spectrometer according to claim 1 ,
wherein the non-linear field region in the curved-field reflectron is configured to focus the ion fragments over at least a major portion of a mass range of the ion fragments without providing additional kinetic energy to the ion fragments to accommodate an energy bandwidth of the curved-field reflectron.
18. A tandem mass spectrometer comprising:
a linear time-of-flight mass analyzer having a field-free drift region;
a curved-field reflectron mass analyzer disposed at an end of the linear time-of-flight mass analyzer such that ions having a plurality of ion masses when formed in the linear time-of-flight analyzer enter the curved-field reflectron mass analyzer,
wherein the curved-field reflectron comprises a drift region and a non-linear field region defined by a series of lens elements;
a mass selection gate disposed between the time-of-flight mass analyzer and the curved-field reflectron mass analyzer, the mass selection gate being located in the field-free drift region, upstream of the non-linear field region, said mass selection gate operable to select an ion mass from said plurality of ion masses;
an ion detector arranged in an ion fragment path; and
a dissociating component located in a path of the ions formed in the linear time-of-flight analyzer,
wherein said dissociating component causes dissociation of said ions into a plurality of ion fragments.
19. The tandem mass spectrometer according to claim 18 ,
wherein said ion detector comprises a channeltron arranged to intercept particles to be measured.
20. The tandem mass spectrometer according to claim 18 ,
wherein said ion detector comprises an electron multiplier arranged to intercept the ion fragments to be measured.
21. The tandem mass spectrometer according to claim 18 ,
wherein said ion detector comprises a micro channel plate assembly arranged to intercept ions to be measured.
22. A tandem mass spectrometer, comprising:
a linear time-of-flight mass analyzer having a field-free drift region;
a curved-field reflectron mass analyzer disposed at an end of the linear time-of-flight mass analyzer such that ions having a plurality of ion masses when formed in the linear time-of-flight analyzer enter the curved-field reflectron mass analyzer,
wherein the curved-field reflectron comprises a drift region and a non-linear field region defined by a series of lens elements;
a mass selection gate disposed between the time-of-flight mass analyzer and the curved-field reflectron mass analyzer, the mass selection gate being located in the field-free drift region, upstream of the non-linear field region, said mass selection gate operable to select an ion mass from said plurality of ion masses; and
a dissociating component located in a path of the ions formed in the linear time-of-flight analyzer,
wherein said dissociating component causes dissociation of said ions into a plurality of ion fragments, wherein the dissociating component comprises a collision chamber.
23. The tandem mass spectrometer according to claim 22 ,
wherein the collision chamber is filled with an inert gas.
24. The tandem mass spectrometer according to claim 1 ,
wherein the dissociating component comprises an electron beam configured to dissociate the ions.
25. The tandem mass spectrometer according to claim 1 ,
wherein the dissociating component comprises an energetic atomic source configured to dissociate the ions.
26. The tandem mass spectrometer according to claim 1 ,
wherein the dissociating component comprises a photon beam configured to dissociate the ions.
27. The tandem mass spectrometer according to claim 1 ,
wherein the mass selection gate is a Bradbury-Nielsen ion gate adapted to select a desired ion mass in said plurality of ion masses.
28. The tandem mass spectrometer according to claim 1 , wherein the dissociating component is disposed after the mass selection gate within the drift region of the curved-field reflectron mass analyzer.
29. The tandem mass spectrometer according to claim 18 , wherein the dissociating component is disposed after the mass selection gate within the drift region of the curved-field reflectron mass analyzer.
30. The tandem mass spectrometer according to claim 22 , wherein the dissociating component is disposed after the mass selection gate within the drift region of the curved-field reflectron mass analyzer.