The present invention implements an ion detector with which it is possible to avoid direct collisions of negative ions with a scintillator, prevent degradation of the scintillator, prolong life of the scintillator, reduce the need for maintenance, and perform highly sensitive detection of both positive and negative ions. With respect to a reference line 65 connecting a central point 63 of a positive ion CD 52 and a central point 64 of a counter electrode 54, a central point 66 of a negative ion CD 53 is provided in a region of a side opposite to a region of a side of a central point 67 of a scintillator 56. Positive ions entering from an ion entrance 62 receive a deflection force and collide with the positive ion CD 52 to generate secondary electrons. The generated secondary electrons collide with the scintillator 56 to generate light. The generated light passes through a light guide 59 and is detected by a photomultiplier tube 58. A negative potential barrier is generated along the reference line 65. Negative ions entering form the ion entrance 62 are attracted to and collide with the negative ion CD 53 to generate positive ions. The generated positive ions collide with the positive ion CD 52 to generate secondary electrons. The generated secondary electrons collide with the scintillator 56 and are detected by the photomultiplier tube 58.

The invention relates to mass spectrometers having secondary electron multipliers with series of discrete dynode stages. The invention particularly relates to an operation with extended dynamic measuring range and extended lifetime. The invention is based on not adapting the dynamic measuring range by control of the gain of the trans-impedance amplifier, nor controlling the multiplier operating voltage, which both are usually too slow, but alternating a number of active and passive dynode stages of a discrete dynode multiplier. Each dynode stage is connected to a discrete voltage supply circuit, being able to be de-energized and short-cut; the multiplier gain is feedback-controlled by energizing or short-cutting dynode stages, serially from the end of the multiplier, as a function of a last measured ion signal; and the multiplier has a single trans-impedance amplifier and a single analog-to-digital converter, measuring and digitizing the output current of the last active dynode stage.

An apparatus includes a first pair of opposing electrode arrangements that confine ions between them in a portion of a confinement volume inwardly laterally in a first confinement direction with respect to a longitudinal ion propagation direction, each opposing electrode arrangement including an arrangement of RF electrodes situated to receive an unbiased RF voltage having an alternate phase between adjacent RF electrodes of the arrangement of RF electrodes so as to provide the confining of ions between the first pair of opposing electrode arrangements, and a second pair of opposing electrode arrangements that confine the ions between the second pair in the confinement volume inwardly laterally in a second confinement direction that complements the first confinement direction, each opposing electrode arrangement of the second pair including an arrangement of RF electrodes that receive an unbiased RF voltage having an alternate phase between adjacent RF electrodes.

A method of injecting analyte ions into a mass analyser comprises: injecting analyte ions of a first charge and counter ions of a second charge into an ion trap; cooling the analyte ions and the counter ions simultaneously in the ion trap such that a spatial distribution of the analyte ions therein is reduced; and injecting the analyte ions as an ion packet from the ion trap into the mass analyser. A mass spectrometer controller is configured to: cause an ion source to inject an amount of analyte ions of a first charge and an amount of counter ions of a second charge into an ion trap; cause the ion trap to simultaneously cool the analyte ions and the counter ions in the ion trap, thereby reducing a spatial distribution of the analyte ions therein; and cause the ion trap to inject the analyte ions into a mass analyser.

The present invention relates to a particle beam mass spectrometer and particle measurement method by means of same. More particularly, the present invention relates to a particle beam mass spectrometer including: a particle focusing unit focusing a particle beam induced by gas flow; an electron gun forming a charged particle beam by accelerating thermal electrons to ionize the particle beam focused by the particle focusing unit; a deflector deflecting the charged particle beam according to kinetic energy to charge ratio; and a sensing unit measuring a current induced by the deflected charged particle beam, wherein the deflector includes at least one particle beam separation electrode provided at each of opposite sides with respect to a progress axis of the charged particle beam before being deflected.

The present invention is concerned with a device for charged particle transportation and manipulation. Embodiments provide a capability of combining positively and negatively charged particles in a single transported packet. Embodiments contain an aggregate of electrodes arranged to form a channel for transportation of charged particles, as well as a source of power supply that provides supply voltage to be applied to the electrodes, the voltage to ensure creation, inside the said channel, of a non-uniform high-frequency electric field, the pseudopotential of which field has one or more local extrema along the length of the channel used for charged particle transportation, at least, within a certain interval of time, whereas, at least one of the said extrema of the pseudopotential is transposed with time, at least within a certain interval of time, at least within a part of the length of the channel used for charged particle transportation.

Among other things, we describe methods and apparatus for the ionization of target molecular analytes of interest, e.g., for use in mass spectrometry. In some implementations, a thin molecular stream is emitted in either single or a split mode and encounters both an electron-impact ion source and trochoidal electron monochromator placed sequentially or coincidentally. The first ion source emits high-energy electrons (70 eV) to generate characteristic positively-charged mass fragment spectra while the second source emits low-energy electrons in a narrow bandwidth to generate negative molecular ions or other ions via electron capture ionization. The dual ion source may be coupled to analytical instruments such as a gas chromatograph and to any number of mass analyzers such as a polarity switching quadrupole mass analyzer or to multiple mass analyzers.

Two complementary approaches to the science of IMS technology, IMS and differential IMS (DIMS), are combined into a single instrument to provide improvements in interference rejection without sacrificing detection sensitivity. The technology is applicable to, inter alia, the analysis of trace quantities of toxic or otherwise dangerous organic chemical materials. The approach improves both sensitivity and specificity (interference rejection) of field detection instrumentation.

A TOFMS includes flight space formation electrodes, an ion detection unit, voltage switching units to switch a voltage to be applied to the flight space formation electrode from a first voltage for flying ions of a first polarity to a second voltage for flying ions of a second polarity, ion information acquisition units to obtain a time of flight or a m/z of the ions based on a detection result of the ions of the second polarity after the voltage has been switched, a correction information storage unit to store correction information related to a deviation in time of flight or a m/z associated with an elapsed time from the switching timing, and a correction unit to correct the flight time or the m/z according to an elapsed time from the switching timing when the detection result of the ion is obtained using the correction information.

A high-voltage power source for applying high voltage to a nozzle of an ESI ion source includes a charge release assistant section including switch circuits 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. For example, when the voltage applied to the nozzle needs to be changed from V.sub.1 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 operates a positive voltage generation section and negative voltage generation section 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 and negative voltage generation section so as to provide voltage V.sub.2.