Abstract: Control of an amplitude of a signal applied to a component of a mass spectrometer is described. In one aspect, a mass spectrometer includes a component and a resonant circuit to generate a radio frequency (RF) signal applied to the component. An amplitude control circuit can be inductively coupled with inductors of the resonant circuit to selectively discharge energy from the resonant circuit and, therefore, adjust the amplitude of the signal in particular situations.

Abstract: An ion source assembly is described that includes an electron source configured to inject electrons into an ion volume to ionize an atom or molecule in the ion volume, wherein the electron source includes a filament. A lens electrode is positioned adjacent the electron source and includes an opening configured to pass electrons therethrough from the electron source into the ion volume. A supply voltage source is coupled to the filament and configured to supply a first voltage to the filament, wherein the first voltage is operable to ionize the molecules in the ion volume. Further, a bias voltage source is coupled to the supply voltage source and configured to supply a bias voltage to the lens electrode. Electrons striking the lens electrode are thereafter returned to the filament.

Abstract: Control of an amplitude of a signal applied to rods of a quadrupole is described. In one aspect, a mass spectrometer includes a quadrupole mass analyzer and a resonant circuit to generate a radio frequency (RF) signal applied to rods of the quadrupole mass analyzer. An amplitude control circuit can be inductively coupled with inductors of the resonant circuit to selectively discharge energy from the resonant circuit and, therefore, adjust the amplitude of the signal in particular situations.

Abstract: Control of an amplitude of a signal applied to a component of a mass spectrometer is described. In one aspect, a mass spectrometer includes a component and a resonant circuit to generate a radio frequency (RF) signal applied to the component. An amplitude control circuit can be inductively coupled with inductors of the resonant circuit to selectively discharge energy from the resonant circuit and, therefore, adjust the amplitude of the signal in particular situations.

Abstract: An ion source assembly is described that includes an electron source configured to inject electrons into an ion volume to ionize an atom or molecule in the ion volume, wherein the electron source includes a filament. A lens electrode is positioned adjacent the electron source and includes an opening configured to pass electrons therethrough from the electron source into the ion volume. A supply voltage source is coupled to the filament and configured to supply a first voltage to the filament, wherein the first voltage is operable to ionize the molecules in the ion volume. Further, a bias voltage source is coupled to the supply voltage source and configured to supply a bias voltage to the lens electrode. Electrons striking the lens electrode are thereafter returned to the filament.

Abstract: Control of an amplitude of a signal applied to rods of a quadrupole is described. In one aspect, a mass spectrometer includes a quadrupole mass analyzer and a resonant circuit to generate a radio frequency (RF) signal applied to rods of the quadrupole mass analyzer. An amplitude control circuit can be inductively coupled with inductors of the resonant circuit to selectively discharge energy from the resonant circuit and, therefore, adjust the amplitude of the signal in particular situations.

Abstract: A process for making a multicomponent fiber is disclosed. The process comprises extruding at least one water dispersible polymer to create a first polymer flow, extruding at least one water non-dispersible synthetic polymer to create a second polymer flow path, directing the resulting multiple polymer flows into a spinneret having a shaped cross section with a plurality of distribution flow paths, and combining the flow paths together to form a multicomponent fiber having a shaped cross section, wherein the multicomponent fiber comprises: (A) at least one water dispersible polymer; and (B) a plurality of domains comprising one or more water non-dispersible polymers, wherein the domains are substantially isolated from each other by the water dispersible polymer intervening between the domains; and wherein the water dispersible polymer is present at the perimeter of the outside cross-section of the multicomponent fiber in a proportion of no greater than 55% water dispersible polymer.

Abstract: A multicomponent fiber having a shaped cross section is provided in this invention. The multicomponent fiber comprises: (A) at least one water dispersible polymer; and (B) a plurality of domains comprising one or more water non-dispersible polymers, wherein said domains are substantially isolated from each other by said water dispersible polymer intervening between said domains; and wherein said water dispersible polymer is present at the perimeter of the outside cross-section of said multicomponent fiber in a proportion of not greater than 55% water dispersible polymer. Articles produced from the multicomponent fiber are also provided.

Abstract: An article is provided comprising a multicomponent fiber having a shaped cross section, wherein the multicomponent fiber comprises: (A) at least one water dispersible polymer; and (B) a plurality of domains comprising one or more water non-dispersible polymers, wherein said domains are substantially isolated from each other by said water dispersible polymer intervening between said domains; and wherein said water dispersible polymer is present at the perimeter of the outside cross-section of said multicomponent fiber in a proportion of not greater than 55% water dispersible polymer.

Abstract: A process for texturing a multicomponent fiber is provided.

Abstract: A multicomponent fiber having a shaped cross section is provided in this invention. The multicomponent fiber comprises: (A) at least one water dispersible polymer; and (B) a plurality of domains comprising one or more water non-dispersible polymers, wherein said domains are substantially isolated from each other by said water dispersible polymer intervening between said domains; and wherein said water dispersible polymer is present at the perimeter of the outside cross-section of said multicomponent fiber in a proportion of not greater than 55% water dispersible polymer. Articles produced from the multicomponent fiber are also provided.

Abstract: A method for operating a mass spectrometer comprises: generating a stream of ions by an ion source; directing the stream of ions into a first one of a pair of ion storage locations and trapping a first portion of the ions therein; directing a packet of ions from the other one of the pair of ion storage locations into an ion cooling cell that damps the kinetic energy of the ions comprising the packet of ions; directing the packet of ions to a mass analyzer of the mass spectrometer for mass analysis thereby; directing the first portion of ions from the first one of the pair of ion storage locations into the ion cooling cell; and directing the first portion of ions to the mass analyzer for mass analysis thereby.

Abstract: An ion detection system for a detecting a quantity of ions exiting from a mass analyzer of a mass spectrometer comprises: (a) photon generating means configured to receive the quantity of ions and to generate a quantity of photons that is proportional to the quantity of ions; (b) a linear array of photo-detectors configured along a line for detecting a variation of a portion of the quantity of generated photons along the line; and (c) an optical system for directing the portion of the quantity of photons from the photon generating means to the linear array of photo-detectors comprising: (c1) a first cylindrical lens having a first lens axis disposed parallel to the line; (c2) a second cylindrical lens or rod lens having a second lens axis disposed parallel to the line; and a doublet lens.

Abstract: A method of mass analysis comprises: generating ions from the sample; delivering the ions to a quadrupole; applying a radio frequency voltage, V, to rods of the quadrupole such that the instantaneous electrical potential of each rod is out of phase with each adjacent rod and a non-oscillatory voltage, U, across each pair of adjacent rods such that a subset of the ions having a range of mass-to-charge (m/z) ratios are selectively transmitted through the quadrupole; varying at least one of voltage U and voltage V such that the range of selectively transmitted m/z ratios is caused to vary and varying at least one additional operational parameter; acquiring a data set comprising a series of temporally-resolved images of spatial distribution patterns of transmitted ions at each combination of U, V and the at least one additional operating parameter; and mathematically deconvolving the data set to generate mass spectra.

Abstract: A detector system for a mass spectrometer comprises: a metal channel dynode (MCD) comprising at least one perforated metal plate configured to receive the exiting ions and eject electrons in response; a plurality of electron-to-photon converters arranged in a parallel stacked configuration, each such converter comprising a substrate plate having a phosphor coating on a first face; and an electrode film disposed on the phosphor coating; at least one photocathode, each of the at least one photocathode disposed between a respective pair of the plurality of electron-to-photon converters; an optical detector optically coupled a last one of the electron-to-photon converters; and at least one direct current power supply configured to apply, in operation, a respective bias electrical potential to the MCD and each of the electrode films and photocathodes.

Abstract: A method for analyzing a sample by mass spectrometry includes producing ions from the sample, delivering the ions to an entrance of a multipole, and applying oscillatory and resolving DC voltages to electrodes of the multipole. The oscillatory and resolving DC voltages cause the multipole to selectively transmit to its distal end ions within a range of mass-to-charge ratios (m/z's) determined by the amplitudes of the oscillatory and resolving DC voltages. The method further includes acquiring data representative of the spatial distributions of ions transmitted by the multipole at a plurality of consecutive time points, and deconvolving the acquired data to produce a mass spectrum. Deconvolving the acquired data includes processing the data to compress a dynamic range of intensity values in the data.

Abstract: A method of mass analysis comprises: generating ions from the sample; delivering the ions to a quadrupole; applying a radio frequency voltage, V, to rods of the quadrupole such that the instantaneous electrical potential of each rod is out of phase with each adjacent rod and a non-oscillatory voltage, U, across each pair of adjacent rods such that a subset of the ions having a range of mass-to-charge (m/z) ratios are selectively transmitted through the quadrupole; varying at least one of voltage U and voltage V such that the range of selectively transmitted m/z ratios is caused to vary and varying at least one additional operational parameter; acquiring a data set comprising a series of temporally-resolved images of spatial distribution patterns of transmitted ions at each combination of U, V and the at least one additional operating parameter; and mathematically deconvolving the data set to generate mass spectra.

Abstract: A method for analyzing a sample by mass spectrometry includes producing ions from the sample, delivering the ions to an entrance of a multipole, and applying oscillatory and resolving DC voltages to electrodes of the multipole. The oscillatory and resolving DC voltages cause the multipole to selectively transmit to its distal end ions within a range of mass-to-charge ratios (m/z's) determined by the amplitudes of the oscillatory and resolving DC voltages. The method further includes acquiring data representative of the spatial distributions of ions transmitted by the multipole at a plurality of consecutive time points, and deconvolving the acquired data to produce a mass spectrum. Deconvolving the acquired data includes processing the data to compress a dynamic range of intensity values in the data.

Abstract: An ion detection system for a detecting a quantity of ions exiting from a mass analyzer of a mass spectrometer comprises: (a) photon generating means configured to receive the quantity of ions and to generate a quantity of photons that is proportional to the quantity of ions; (b) a linear array of photo-detectors configured along a line for detecting a variation of a portion of the quantity of generated photons along the line; and (c) an optical system for directing the portion of the quantity of photons from the photon generating means to the linear array of photo-detectors comprising: (c1) a first cylindrical lens having a first lens axis disposed parallel to the line; (c2) a second cylindrical lens or rod lens having a second lens axis disposed parallel to the line; and a doublet lens.

Abstract: Systems, methods, and apparatuses are provided for tuning a mass spectrometer. An optimization process can be performed to determine optimal parameters for various physical parameters of elements of the mass spectrometer. A cost function (metric) can be defined for optimizing a measured signal output from the spectrometer. The metric can include an intensity term and a rectangularity term. The rectangularity term can provide a quantification of an extent that a measured signal corresponding to a first mass-to-charge ratio approximates a rectangle. The parameter values can be adjusted to find an optimal cost value of the cost function. Techniques may particularly useful when a quadrupole is operated in a broad-stability mode.