Patent classifications
H01J49/403
Accelerator for multi-pass mass spectrometers
Improved pulsed ion sources and pulsed converters are proposed for multi-pass time-of-flight mass spectrometer, either multi-reflecting (MR) or multi-turn (MT) TOF. A wedge electrostatic field (45) is arranged within a region of small ion energy for electronically controlled tilting of ion packets (54) time front. Tilt angle γ of time front (54) is strongly amplified by a post-acceleration in a flat field (48). Electrostatic deflector (30) downstream of the post-acceleration (48) allows denser folding of ion trajectories, whereas the injection mechanism allows for electronically adjustable mutual compensation of the time front tilt angle, i.e. γ=0 for ion packet in location (55), for curvature of ion packets, and for the angular energy dispersion. The arrangement helps bypassing accelerator (40) rims, adjusting ion packets inclination angles α.sub.2 and what is most important, compensating for mechanical misalignments of the optical components.
MULTI-PASS MASS SPECTROMETER
Improved multi-pass time-of-flight mass spectrometers MPTOF, either multi-reflecting (MR) or multi-turn (MT) TOF are proposed with elongated pulsed converters—either orthogonal accelerator or radially ejecting ion trap. The converter 35 is displaced from the MPTOF s-surface of isochronous ion motion in the orthogonal Y-direction. Long ion packets 38 are pulsed deflected in the transverse Y-direction and brought onto said isochronous trajectory s-surface, this way bypassing said converter. Ion packets are isochronously focused in the drift Z-direction within or immediately after the accelerator, either by isochronous trans-axial lens/wedge 68 or Fresnel lens. The accelerator is improved by the ion beam confinement within an RF quadrupolar field or within spatially alternated DC quadrupolar field. The accelerator improves the duty cycle and/or space charge capacity of MPTOF by an order of magnitude.
ANALYTICAL DEVICE
An analytical device includes: a first electrode to which a pulse voltage for accelerating ions is applied; at least one switching element that controls application of the pulse voltage to the first electrode; a second electrode that defines a space in which the ions fly; an ion detector that detects the ions; and a vacuum vessel that has the second electrode inside, wherein: the switching element is in contact with an insulator, and the insulator is in contact with the vacuum vessel.
Time-of-flight mass spectrometer
An acceleration voltage generator is configured to cause a power MOSFET to turn on or off to switch a high direct-current voltage, so as to generate a high-voltage pulse for an ejection of ions from an ion ejector. A drive signal is used to cause the power MOSFET to turn on, and further includes a secondary drive signal to recharge a gate capacitance to cause the power MOSFET to stay in an on-state. In a drive signal generator, edge detection circuits generate an edge detection signal based on a start signal; selection circuits generate a primary drive signal by adjusting the edge detection signal in its signal width; and a secondary drive signal generator includes multiple circuit elements such as a semiconductor element, and generates the secondary drive signal.
MASS SPECTROMETER
A drive unit for driving an acceleration electrode of a mass spectrometer is disclosed. The drive unit includes a power converter comprising a switching element and pulsing circuitry that can form output pulses suitable for driving an acceleration electrode of a mass spectrometer. The drive unit also includes a controller that is configured to synchronise operation of the switching element with the pulsing circuitry.
Time of flight mass spectrometer and method of mass spectrometry
A time-of-flight (ToF) mass spectrometer, comprising: a pulsed ion injector for forming an ion beam that travels along an ion path; a detector for detecting ions in the ion beam that arrive at the detector at times according to their m/z values; an ion focusing arrangement located between the ion injector and the detector for focusing the ion beam in at least one direction orthogonal to the ion path; and a variable voltage supply for supplying the ion focusing arrangement with at least one variable voltage that is dependent on a charge state and/or an amount of ions of at least one species of ions in the ion beam. A corresponding method of mass spectrometry is provided. The charge state and/or an amount of ions may be acquired from a pre-scan, or predicted. Tuning of the spectrometer based on a charge state and/or an amount of ions of at least one species of ions in the ion beam may be performed on the fly.
MULTI-PASS MASS SPECTROMETER
Improved multi-pass time-of-flight mass spectrometers MPTOF, either multi-reflecting (MR) or multi-turn (MT) TOF are proposed with elongated pulsed converters—either orthogonal accelerator or radially ejecting ion trap. The converter 35 is displaced from the MPTOF s-surface of isochronous ion motion in the orthogonal Y-direction. Long ion packets 38 are pulsed deflected in the transverse Y-direction and brought onto said isochronous trajectory s-surface, this way bypassing said converter. Ion packets are isochronously focused in the drift Z-direction within or immediately after the accelerator, either by isochronous trans-axial lens/wedge 68 or Fresnel lens. The accelerator is improved by the ion beam confinement within an RF quadrupolar field or within spatially alternated DC quadrupolar field. The accelerator improves the duty cycle and/or space charge capacity of MPTOF by an order of magnitude.
Time-of-flight mass spectrometer
A transfer electrode unit (240) is configured by coaxially arranging a plurality of loop electrodes (241A, 241B, 241C), and guides ions to an orthogonal acceleration region (242C) by allowing the ions to pass through an inner side of the plurality of electrodes (241A, 241B, 241C) each of which is applied with a voltage. A voltage having a higher absolute value than the voltage applied to the plurality of electrodes (241A, 241B, 241C) is applied to a flight tube (246), and the ions accelerated in the orthogonal acceleration region (242C) are introduced to a flight space formed in the flight tube (246). A shield portion (241F) is provided between the transfer electrode unit (240) and the flight tube (246), and suppresses that an electric field derived from the voltage applied to the flight tube (246) enters the transfer electrode unit (240).
Time of flight mass spectrometer coupled to a core sample source
In one aspect, a time-of-flight mass spectrometer includes a source comprising a backing plate configured to operably couple to a core sample containing component, and an acceleration region. The time-of-flight mass spectrometer also includes a time-of-flight mass analyzer operably associated with the source region. In some embodiments, the core sample core sample containing component is a coring drill bit. In some embodiments, core containing component is configured to couple to the backing plate of the source region from the opposite side of the acceleration region. In some embodiments, core containing component is configured to couple to the backing plate of the source region on the acceleration region side of the backing plate. In some embodiments, the acceleration region is a single-stage acceleration region. In other embodiments, the acceleration region is a two-stage acceleration region.
PULSED ACCELERATOR FOR TIME OF FLIGHT MASS SPECTROMETERS
A pulsed accelerator for a Time of Flight mass spectrometers comprising a set of parallel electrodes. The accelerator is inclined at an oblique angle to the incoming ion beam defined by the ratio of the incoming ion beam velocity spreads axial and transverse to the beam. Additionally a deflection electrode is included to deflect unwanted ions away from the detector during the fill cycle of the accelerator.