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.

A high-voltage power source for applying high voltage to a nozzle of an ESI ion source includes a charge release assistant section (26) including switch circuits (62 and 65) and other elements for forcing electric charges accumulated at output terminals to be discharged in a polarity-switching operation, whereby the positive/negative switching of the polarity of the output voltage can be quickly performed. In the mass spectrometer according to the present invention, for example, when the voltage applied to the nozzle needs to be changed from Vi to V.sub.2 (where V.sub.1 and V.sub.2 are positive, and V.sub.1>V.sub.2), a voltage control section (20) under the command of a main controller (9) operates a positive voltage generation section (21) and negative voltage generation section (23) so as to temporarily provide a negative output voltage. After a predetermined period of time, the voltage control section operates the positive voltage generation section (21) and negative voltage generation section (23) so as to provide voltage V.sub.2. If the voltage was simply changed from V.sub.1 to V.sub.2, the voltage would decrease slowly and require considerable time for the change. The positive/negative switching of the polarity induces the discharging of the electric charges accumulated at the output terminals, and consequently, the voltage-switching operation from V.sub.1 to V.sub.2 is quickly performed.

A mass spectrometer (1) includes: an ionization section (201) configured to generate ions from a sample; a mass separation section (231, 235) configured to separate ions generated by the ionization section according to mass-to-charge ratio; an ion detector (237) configured to detect an ion separated by the mass separation section; an ion capture section (31) configured to capture ions separated by the mass separation section; and an electron beam detection section (32) configured to detect an electron beam diffracted by ions captured within the ion capture section (31). This mass spectrometer is capable of performing, in a single measurement operation, both a mass spectrometric analysis and an electron-beam diffraction measurement for distinguishing between isomers. The electron-beam diffraction measurement can be more efficiently performed than in a conventional device of this type.

An instrument for separating ions may include an ion source in a first pressure environment at a first pressure and configured to generate ions from a sample, an ion separation instrument, controlled to an instrument pressure that is less than the first pressure, and configured to separate ions as a function of at least one molecular characteristic and an interface, controlled to a second pressure less than the first pressure and greater than the instrument pressure, for transporting the generated ions from the first pressure environment into the ion separation instrument operating at the instrument pressure. The interface may include a sealed ion funnel defining an axial passageway therethrough, and an ion carpet sealed to the first ion funnel. A portion of the axial passageway tapers from a first cross-sectional area to a reduced cross-sectional area such that the tapered axial passageway defining a virtual jet disrupter therein.

Mass spectrometry for a specimen is repeatedly performed while stepwise changing a parameter (for example, a current value) of an emitter current. Based on a plurality of chromatograms generated by this process, an evaluation value table including a plurality of evaluation values is generated. An individual evaluation value shows a degree of tailing for individual peak included in each chromatogram. A parameter function is generated based on the evaluation value table. The parameter of the emitter current is controlled according to the parameter function.

A CDMS may include an ELIT having a charge detection cylinder (CD), a charge generator for generating a high frequency charge (HFC), a charge sensitive preamplifier (CP) having an input coupled to the CD and an output configured to produce a charge detection signal (CHD) in response to a charge induced on the CD, and a processor configured to (a) control the charge generator to induce an HFC on the CD, (b) control operation of the ELIT to cause a trapped ion to oscillate back and forth through the CD each time inducing a charge thereon, and (c) process CHD to (i) determine a gain factor as a function of the HFC induced on the CD, and (ii) modify a magnitude of the portion of CHD resulting from the charge induced on the CD by the trapped ion passing therethrough as a function of the gain factor.

An improved multi-pass time-of-flight or electrostatic trap mass spectrometer (70) with an orthogonal accelerator, applicable to mirror based multi-reflecting (MR) or multi-turn (MT) analyzers. The orthogonal accelerator (64) is tilted and after first ion reflection or turn the ion packets are back deflected with a compensated deflector (40) by the same angle α to compensate for the time-front steering and for the chromatic angular spreads. The focal distance of deflector (40) is control by Matsuda plates or other means for producing quadrupolar field in the deflector. Interference with the detector rim is improved with dual deflector (68). The proposed improvements allow substantial extension of flight path and number of ion turns or reflections. The problems of analyzer angular misalignments by tilting of ion mirror (71) is compensated by electrical adjustments of ion beam (63) energy and deflection angles in deflectors (40) and (68).

A high-voltage (HV) power supply outputs an output voltage based on a control signal produced by a dual analog/digital feedback loop. The control signal is determined at least in part by an error amplifier that receives a measurement signal, proportionally attenuated from the output voltage, and a digital-to-analog converter (DAC) output signal. An analog-to-digital converter (ADC) also receives the measurement signal and transmits it in digitized form to a digital processor. The digital processor calculates a digital DAC data signal based on the measurement signal, and on a digital set-point input signal corresponding to a set-point voltage value of the output voltage desired to be outputted from the high-voltage source. A DAC receives the DAC data signal and converts it to the DAC output signal transmitted to the error amplifier.

A method of operating a quadrupole device is disclosed that comprises operating the quadrupole device in a first mode of operation, and operating the quadrupole device in a second mode of operation. Operating the quadrupole device in the first mode of operation comprises applying one or more first voltages to the quadrupole device such that the quadrupole device is operated in an initial stability region and such that at least some ions are stable within the quadrupole device. Operating the quadrupole device in the second mode of operation comprises applying one or more second voltages to the quadrupole device such that the quadrupole device is operated in a different stability region and such that at least some of the ions that were stable within the quadrupole device in the first mode of operation are stable within the quadrupole device in the second mode of operation.

To acquire a mass spectrum for a wide mass range, a normal analysis execution controlling unit controls components to repeatedly perform measurement while changing setting m/z by a predetermined m/z at a time, and a mass spectrum summarizing processing unit summarizes data pieces each obtained by each time of measurement to generate the mass spectrum. Radio-frequency voltage applied to an ion guide and the like is changed based on the setting m/z. The radio-frequency voltage for the setting m/z is determined using a table in which a relationship between a position on an axis between upper and lower limits of the mass range and the radio-frequency voltage is substantially the same regardless of the mass range.