Abstract: A secondary electron multiplier includes: a conversion dynode for emitting a secondary electron in response to an incident ion; a plurality of dynodes configured to have multi-stages from second to final stages for receiving the secondary electron; and a first voltage applying device for applying a first negative voltage to the conversion dynode and sequentially dividing the first negative voltage to apply to each of the second-stage and subsequent dynodes, wherein the secondary electron multiplier is configured to sequentially multiply the emitted secondary electron by the second-stage and subsequent dynodes. In the secondary electron multiplier, any of the second-stage and subsequent dynodes have a second voltage applying device for applying a second negative voltage. The secondary electron multiplier has an improved ion detection efficiency without a large reduction of a usable period thereof, thereby enhancing the sensitivity of a mass spectrometer.

Abstract: A mass spectrometer includes: a plasma generation device for generating plasma for ionizing an introduced sample; an interface device for drawing the plasma into vacuum; an ion lens device for extracting and inducing ions as an ion beam from the plasma; a collision/reaction cell for removing an interference ion from the ion beam; a mass analyzer or filter for allowing a predetermined ion in the ion beam from the collision/reaction cell to pass along a first axis based on a mass-to-charge ratio; an ion detector for detecting the ion; an ion deflection device before the mass analyzer, and also an ion deflection device between the mass analyzer and the ion detector. The mass spectrometer reduces background noises in a mass analyzer by removing neutral particles from the ion beam without reducing the measurement sensitivity on ions to be analyzed as much as possible.

Abstract: A secondary electron multiplier includes: a conversion dynode for emitting a secondary electron in response to an incident ion; a plurality of dynodes configured to have multi-stages from second to final stages for receiving the secondary electron; and a first voltage applying device for applying a first negative voltage to the conversion dynode and sequentially dividing the first negative voltage to apply to each of the second-stage and subsequent dynodes, wherein the secondary electron multiplier is configured to sequentially multiply the emitted secondary electron by the second-stage and subsequent dynodes. In the secondary electron multiplier, any of the second-stage and subsequent dynodes have a second voltage applying device for applying a second negative voltage. The secondary electron multiplier has an improved ion detection efficiency without a large reduction of a usable period thereof, thereby enhancing the sensitivity of a mass spectrometer.

Abstract: A mass spectrometer includes: a plasma generation device for generating plasma for ionizing an introduced sample; an interface device for drawing the plasma into vacuum; an ion lens device for extracting and inducing ions as an ion beam from the plasma; a collision/reaction cell for removing an interference ion from the ion beam; a mass analyzer or filter for allowing a predetermined ion in the ion beam from the collision/reaction cell to pass along a first axis based on a mass-to-charge ratio; an ion detector for detecting the ion; an ion deflection device before the mass analyzer, and also an ion deflection device between the mass analyzer and the ion detector. The mass spectrometer reduces background noises in a mass analyzer by removing neutral particles from the ion beam without reducing the measurement sensitivity on ions to be analyzed as much as possible.

Abstract: A method of determining a coefficient for converting an analog current value into a pulse count value in an inductively coupled plasma mass spectroscopy apparatus (ICP-MS) is described. The ICP-MS is configured to generate the pulse count value and the analog current value as a signal intensity indicating a density of an element in a sample to be measured.

Abstract: The present invention performs measurement for determining a P/A coefficient and/or determination of the P/A coefficient after measurement of a standard density sample for density calibration in an ICP-MS. Specifically, after measuring signal intensity of each mass number in the standard density sample, the P/A coefficient is determined from the signal intensity for a mass number having the signal intensity within a P/A coefficient calibration range, while for a mass number having the signal intensity above the calibration range, a voltage applied to an ion lens of the ICP-MS is changed so that the signal intensity becomes within the calibration range, to thereby adjust an ion transmission ratio of the ion lens, and then the P/A coefficient is determined from the signal intensity determined within the calibration range.

Abstract: Provided is a plasma ion source mass spectrometer with an ion deflector lens having an improved removal ratio of photons and neutral particles as compared with the conventional art while an ion transmittance is maintained. The ion deflector includes an input side plate-like electrode, an output side plate-like electrode, and a tubular electrode disposed between the input side plate-like electrode and the output side plate-like electrode. The tubular electrode is of a point asymmetrical configuration. The tubular electrode is arranged so that a center axis of the tubular electrode is closer to an axis of travel of ions upstream of the input side plate-like electrode than an axis of travel of ions downstream of the output side plate-like electrode.

Abstract: Provided is a plasma ion source mass spectrometer with an ion deflector lens having an improved removal ratio of photons and neutral particles as compared with the conventional art while an ion transmittance is maintained. The ion deflector includes an input side plate-like electrode, an output side plate-like electrode, and a tubular electrode disposed between the input side plate-like electrode and the output side plate-like electrode. The tubular electrode is of a point asymmetrical configuration. The tubular electrode is arranged so that a center axis of the tubular electrode is closer to an axis of travel of ions upstream of the input side plate-like electrode than an axis of travel of ions downstream of the output side plate-like electrode.