Abstract: An ion source includes structure having separate first and second ion volumes therein, and electron source structure having first and second portions that selectively supply electrons to the first and second ion volumes, respectively. The electron source structure has a first operational mode in which the second portion substantially prevents a supply of electrons to the second ion volume and in which electrons are supplied to the first ion volume under control of the first portion, and has a second operational mode in which the first portion substantially prevents a supply of electrons to the first ion volume and in which electrons are supplied to the second ion volume under control of the second portion.

Abstract: A variable duty cycle ion source assembly is coupled to a continuous beam mass spectrometer. The duty cycle can be adjusted based on previous scan data or real time sampling of ion intensities during mass analysis. This provides the ability to dynamically control the total number of ions formed, mass analyzed and detected for each ion mass of interest. A reflection mechanism that provides a variable duty cycle, enables electrons to be reflected through an ion volume multiple times before atoms or molecules are ionized in the ion volume, thereby providing for dynamic control of the ion population.

Abstract: A method and apparatus for directing ions from an ionization source to a mass analyzer is provided. The method includes producing ions from a sample in an ionization source. Some of the ions are transferred to a first region via a passageway that is in fluid communication with the ionization source. Next, some of the ions are sampled from the first region into a second region via an aperture that is defined thorough a partition element. The aperture is centered about a longitudinal axis that passes through an ion transfer element within the second region. An electric field is established for deflecting some of the ions that pass through the aperture of the partition element. In particular, the electric field is directed transverse to the longitudinal axis such that relatively more ions enter an input end of the ion transfer element compared to when the ions are not deflected.

Abstract: The current invention facilitates the construction of a compact high performance quadrupole mass analyzer which has the operational characteristics of a modern research grade system and the ergonomic and cost structure of a moderate benchtop system. A multipole field device is physically located within the windings of the RF resonant circuit. By combining the space consumed by the RF windings and its housing and the space consumed by the multipole field device and its vacuum housing, the overall size of the resultant mass spectrometer is reduced.

Abstract: A MALDI/LDI source includes an ion collection device, e.g., a skimmer, orifice, mass analyzer, ion transfer optics and/or ion guide, configured for use with a short focal length lens with a large aperture. In some embodiments, the ion collection device includes an outer edge that can be disposed approximately parallel to a beam envelope between a lens and a focal point positioned at a MALDI/LDI sample. This configuration of the outer edge allows the ion collection device to be placed in close proximity to the focal point. This placement results in favorable collection efficiencies of laser desorbed analyte from the MALDI/LDI sample.

Abstract: A method and apparatus are provided for operating a linear ion trap. A linear ion trap configuration is provided that allows for increased versatility in functions compared to a conventional three-sectioned linear ion trap. In operation, the linear ion trap provides multiple segments, the segments spatially portioning an initial population of ions into at least a first and a second ion population. Each segment is effectively independent and ions corresponding to the first ion population are able to be manipulated independently from ions corresponding to ions corresponding to the second ion population; the ions having been generated by an ion source under the same conditions. The ions can then be expelled from the ion trap.

Abstract: An apparatus and method are disclosed for efficient detection of ions ejected from a quadrupolar ion trap, in which the ions are ejected as first and second groups of ions having different directions. The first and second groups of ions are received by a conversion dynode structure, which responsively emits secondary particles that are directed to a shared detector, such as an electron multiplier. The conversion dynode structure may be implemented as a common dynode or as two dynodes (or sets of dynodes), with each dynode positioned to receive one of the groups of ions.

Abstract: An apparatus for releasably gripping a sample plate for use with a mass spectrometer has been developed, the sample plate having substantially parallel faces and a peripheral surface. The apparatus comprises a planar member and first and second guiding structures. The second guiding structure comprises a biasing mechanism which when activiated, provides a force that forces the second guiding structure towards the peripheral surface of the sample plate such that the sample plate is retained by the apparatus. Utilization of the configuration reduces frictional point contact thus reduces localized stress point resulting in yielding the surface material thus in effect guarding both sample plate and first guiding means from galling and/or reducing any type of material removal when gripping a sample plate, or releasing a sample plate.

Abstract: A new sample plate handling apparatus for use with mass analysis, and methods for use the same have been developed. The sampling plate handling apparatus comprises a sample plate receiver which receives the sample plate in a first plane, a rotating device for rotating the sample plate from the first plane to a second plane, and a relocation device that relocates the sample plate in the second plane such that one of the samples on the sample plate is in the position desired for analysis by the mass analyzer. In one implementation, the relocation device can relocate the sample plate such that a beam of radiation that irradiates a sample on the sample plate emanates ionized particles that are substantially aligned with ion transfer optics of the mass analyzer.

Abstract: A detector assembly has a current measuring device with a saturation threshold level, and a gain variation means. A signal is generated in response to the particles detected, a first data point corresponding to a peak of interest is acquired from the signal. If the first data point is near, at or above the saturation threshold level of the current measuring device, the gain of the gain variation means is adjusted such that the peak of interest in the signal is reduced in intensity.

Abstract: A MALDI/LDI source is disclosed that includes an ion optical device and beam-focusing optics disposed on opposite sides of a sample support that is at least locally transparent in a region underlying the sample to allow transmission of a radiation beam therethrough. A laser or other radiation source, located adjacent a rear surface of the sample support, emits a beam of radiation that is focused by the beam focusing optics and traverses the transparent region of the sample support to impinge on the sample. Ions produced by irradiation of the sample are collected by an ion optical device located adjacent the front surface of the sample support. By locating the ion optical device and beam-focusing optics on opposite sides of the sample support, short focal length beam-focusing optics may be utilized, thereby facilitating smaller beam spot sizes. This may be particularly useful for mass spectral tissue imaging and other applications where high spatial resolution analysis of a differentiated sample is desirable.

Abstract: An aperture design for a linear ion trap is provided in which the aperture is optimized to minimize possible axial field inhomogeneities whilst preserving the structural integrity of the quadrupole rods. In general, the invention provides a linear ion trap for trapping and subsequently ejecting ions. The linear ion trap comprises a plurality of rods which define an interior trapping volume which has an axis extending longitudinally. One or more of the rods includes an aperture which extends both radially through the rod and longitudinally along the rod. The aperture being configured such that the ions can pass from the interior trapping volume through the aperture to a region outside the interior trapping volume. At least one recess is disposed adjacent the aperture, extending longitudinally along the rod and facing the interior trapping volume, the recess not extending radially through the rod.

Abstract: A three section linear or two-dimensional (2D) quadrupole ion trap as a high performance mass spectrometer is described. Mass analysis is performed by ejecting ions radically out slots formed in at least two of the rods using the mass selective instability mode of operation. The slot geometry is optimized to enable ions of different mass ranges to be scanned out of differently dimensioned slots. Multiple detectors arranged to receive ejected ions in multiple directions provide the ability to simultaneously or sequentially scan or perform mass analysis of ions of different natures.

Abstract: An apparatus that comprises material which have different thermal expansion coefficients, combined in such a way that the length of the drift region is variant, and self adjusting with temperature. The adjustment is such as to compensate for the length changes resulting from thermal expansion or contraction in other ion optical elements, such that ions of substantially equivalent mass to charge ratios maintain a constant flight time though the system. This allows for use of standard construction methods for the ion optical elements.

Abstract: A detector assembly including a support element, a first capacitor plate and a second capacitor plate. The support element is configured to attach the detector assembly to a chamber wall that separates a lower pressure region and a higher pressure region. A surface of the second capacitor plate is spaced apart from a surface of the first capacitor plate to define a capacitor gap. The first capacitor plate is positioned to be inside the lower pressure region when the detector assembly is attached to the chamber wall. The second capacitor plate is supported by the support element through insulating couplings. The detector assembly also includes a means for reducing mechanical load on the insulating couplings between the second capacitor plate and the support element. The reduced mechanical load includes load caused by a pressure difference between the lower and higher pressure regions.