Abstract: Control of an amplitude of a signal applied to rods of a quadrupole is described. In one aspect, a mass spectrometer includes an amplifier circuit that causes a radio frequency (RF) signal to be applied to the rods of the quadrupole. A controller circuit can determine that the actual amplitude of the RF signal differs than the expected amplitude and, in response, identify current and past environmental and performance parameters to adjust the amplitude.

Abstract: A metal-channel conversion dynode comprises: a wafer comprising a first face and a second face parallel to the first face and having a thickness less than 1000 ?m; and a plurality of channels passing through the wafer from the first face to the second face at an angle to a plane of the first face and a plane of the second face. In some embodiments, each inter-channel distance may be substantially the same as the wafer thickness. In some embodiments, the wafer is fabricated from tungsten. In some other embodiments, the wafer comprises a non-electrically conductive material that is fabricated by three-dimensional (3D) printing or other means and that is coated, on its faces and within its channels, with a metal or suitably conductive coating that produces secondary electrons upon impact by either positive or negative ions.

Abstract: A metal-channel conversion dynode comprises: a wafer comprising a first face and a second face parallel to the first face and having a thickness less than 1000 ?m; and a plurality of channels passing through the wafer from the first face to the second face at an angle to a plane of the first face and a plane of the second face. In some embodiments, each inter-channel distance may be substantially the same as the wafer thickness. In some embodiments, the wafer is fabricated from tungsten. In some other embodiments, the wafer comprises a non-electrically conductive material that is fabricated by three-dimensional (3D) printing or other means and that is coated, on its faces and within its channels, with a metal or suitably conductive coating that produces secondary electrons upon impact by either positive or negative ions.

Abstract: Disclosed herein are systems and methods for a mass spectrometer having a multipole configured to pass an ion stream, and a detector configured to detect the properties of the abundance of ions represented by data points. The mass spectrometer also includes a processing system that is configured to obtain a plurality of paired data points (e.g., detector data points and RF amplitude data points), and identify, based on centroiding a portion of the plurality of paired data points, at least one characteristic of a peak and determine, based on the at least one characteristic of the peak, a preferred peak shape.

Abstract: A mass spectrometer support apparatus includes a deconvolution logic and a centroider logic. The deconvolution logic is configured to deconvolve a mass spectrum measured by a mass spectrometer using an approximate peak shape. The centroider logic is configured to integrate the deconvolved spectrum and populate a sparse vector of peak locations.

Abstract: A mass spectrometer support apparatus includes a peak shape logic to determine one or more peak shapes using a calibration mass spectrum and known peak locations; and a tuning logic to adjust instrument parameters to achieve a selected peak width. A method for tuning a quadrupole-based mass spectrometer includes determining one or more peak shapes using a calibration mass spectrum and known peak locations; and adjusting instrument parameters to achieve a selected peak width.

Abstract: Control of an amplitude of a signal applied to rods of a quadrupole is described. In one aspect, a mass spectrometer includes an amplifier circuit that causes a radio frequency (RF) signal to be applied to the rods of the quadrupole. A controller circuit can determine that the actual amplitude of the RF signal differs than the expected amplitude and, in response, identify current and past environmental and performance parameters to adjust the amplitude.

Abstract: A mass spectrometer includes an ion source configured to produce ions from a sample; a set of quadrupole rods configured to select ions based on a mass-to-charge ratio; a DC rod driver configured to produce a voltage; a DC rod driver filter configured to filter RF frequency interference; and a controller. The controller is configured to utilize the results of the constrained convex optimization to cause a DC rod drive to produce the DC filter input and provide a required voltage to the set of quadrupole rods, the constrained convex utilizing a impulse response curve of the DC rod driver filter to determine a DC filter input to achieve the required voltage on the set of quadrupole rods; select ions passing through the set of quadrupole rods based on the mass-to-charge ratio; and measure the intensity of the ions.

Abstract: Control of an amplitude of a signal applied to rods of a quadrupole is described. In one aspect, a mass spectrometer includes an amplifier circuit that causes a radio frequency (RF) signal to be applied to the rods of the quadrupole based on an amplifier RF input signal. An analog-to-digital converter (ADC) can generate a digital representation of the RF signal. A controller circuit can receive the digital representation and adjust an amplitude of the amplifier RF input signal based on differences between an amplitude of a fundamental frequency of the RF signal being different than an expected amplitude.

Abstract: Control of an amplitude of a signal applied to rods of a quadrupole is described. In one aspect, a mass spectrometer includes an amplifier circuit that causes a radio frequency (RF) signal to be applied to the rods of the quadrupole. A controller circuit can determine that the actual amplitude of the RF signal differs than the expected amplitude and, in response, identify current and past environmental and performance parameters to adjust the amplitude.

Abstract: Control of an amplitude of a signal applied to rods of a quadrupole is described. In one aspect, a mass spectrometer includes an amplifier circuit that causes a radio frequency (RF) signal to be applied to the rods of the quadrupole based on an amplifier RF input signal. An analog-to-digital converter (ADC) can generate a digital representation of the RF signal. A controller circuit can receive the digital representation and adjust an amplitude of the amplifier RF input signal based on differences between an amplitude of a fundamental frequency of the RF signal being different than an expected amplitude.

Abstract: Control of an amplitude of a signal applied to rods of a quadrupole is described. In one aspect, a mass spectrometer includes an amplifier circuit that causes a radio frequency (RF) signal to be applied to the rods of the quadrupole. A controller circuit can determine that the actual amplitude of the RF signal differs than the expected amplitude and, in response, identify current and past environmental and performance parameters to adjust the amplitude.

Abstract: A metal-channel conversion dynode comprises: a wafer comprising a first face and a second face parallel to the first face and having a thickness less than 1000 ?m; and a plurality of channels passing through the wafer from the first face to the second face at an angle to a plane of the first face and a plane of the second face. In some embodiments, each inter-channel distance may be substantially the same as the wafer thickness. In some embodiments, the wafer is fabricated from tungsten. In some other embodiments, the wafer comprises a non-electrically conductive material that is fabricated by three-dimensional (3D) printing or other means and that is coated, on its faces and within its channels, with a metal or suitably conductive coating that produces secondary electrons upon impact by either positive or negative ions.

Abstract: A mass spectrometer is described that includes a multipole configured to pass an ion stream, the ion stream comprising an abundance of one or more ion species within stability boundaries defined by (a, q) values. A detector formed by a plurality of dynodes is configured to detect the spatial and temporal properties of the abundance of ions, where each dynode arranged such that it is struck by ions in a known spatial relationship with the ion stream. The detector also includes a plurality of charged particle detectors, each associated with one or more of the plurality of dynodes. A processing system is configured to record and store a pattern of detection of ions in the abundance of ions by the dynodes in the detector.

Abstract: A mass spectrometer is described that includes a multipole configured to pass an ion stream, the ion stream comprising an abundance of one or more ion species within stability boundaries defined by (a, q) values. A detector formed by a plurality of dynodes is configured to detect the spatial and temporal properties of the abundance of ions, where each dynode arranged such that it is struck by ions in a known spatial relationship with the ion stream. The detector also includes a plurality of charged particle detectors, each associated with one or more of the plurality of dynodes. A processing system is configured to record and store a pattern of detection of ions in the abundance of ions by the dynodes in the detector.

Abstract: Techniques are provided for scanning frequency and voltages of a multipole mass filter while maintaining substantially the same number of AC cycles per mass during a scan across a range of masses. For example, a mass spectrum can be obtained by controlling a DC axial voltage that accelerates ions into a mass filter, a DC resolving voltage applied to the mass filter, an AC voltage amplitude applied to the mass filter, and an AC frequency of the AC voltage. The settings can be controlled such that ions of different mass-to-charge ratios are within the mass filter for substantially a same number of AC cycles. To achieve the same number of AC cycles, the AC frequency is changed during the scan. For low masses, a higher AC frequency can be used. For high masses, a lower AC frequency can be used.

Abstract: Techniques are provided for scanning frequency and voltages of a multipole mass filter while maintaining substantially the same number of AC cycles per mass during a scan across a range of masses. For example, a mass spectrum can be obtained by controlling a DC axial voltage that accelerates ions into a mass filter, a DC resolving voltage applied to the mass filter, an AC voltage amplitude applied to the mass filter, and an AC frequency of the AC voltage. The settings can be controlled such that ions of different mass-to-charge ratios are within the mass filter for substantially a same number of AC cycles. To achieve the same number of AC cycles, the AC frequency is changed during the scan. For low masses, a higher AC frequency can be used. For high masses, a lower AC frequency can be used.

Abstract: Non-negative contributions to a spectrum from time-varying spectroscopy data can be determined. Reference basis functions can transform spectroscopy data into an equation (e.g., an objective function). Each reference basis function can correspond to a different time and a different particle, e.g., a different mass. The objective function can include a noise vector that modifies the spectroscopy data to provide a solution that is constrained to be non-negative. The noise vector can be estimated by minimizing the objective function to obtain an estimated vector, which can be truncated that satisfies a given constraint. The noise vector can be computed from the difference of the estimated vector and the truncated vector, and be accumulated. The noise vector can be used to update the objective function, thereby providing a new estimated vector in an iterative loop.