Systems and methods taught herein generate a non-uniform magnetic field in the ionization region of an ion source to improve robustness in electrical and chemical ionization processes, particularly negative chemical ionization (CI) processes. The non-uniform magnetic field within the ionization volume spatially separates electrons and anions such that anions primarily pass through an ion exit aperture in the ionization chamber while electrons are directed to strike side walls or end walls of the ionization chamber away from the ion exit aperture. As a result, greater numbers of ions exit from the ion source towards a mass analyzer. Systems and methods taught herein also increase the longevity of instrumentation by avoiding damage that can be caused by electrons striking surfaces around apertures.

A miniature, low cost mass spectrometer capable of unit resolution over a mass range of 10 to 50 AMU. The mass spectrometer incorporates several features that enhance the performance of the design over comparable instruments. An efficient ion source enables relatively low power consumption without sacrificing measurement resolution. Variable geometry mechanical filters allow for variable resolution. An onboard ion pump removes the need for an external pumping source. A magnet and magnetic yoke produce magnetic field regions with different flux densities to run the ion pump and a magnetic sector mass analyzer. An onboard digital controller and power conversion circuit inside the vacuum chamber allows a large degree of flexibility over the operation of the mass spectrometer while eliminating the need for high-voltage electrical feedthroughs. The miniature mass spectrometer senses fractions of a percentage of inlet gas and returns mass spectra data to a computer.

In order to attain a main objective of the present invention to provide an ion source capable of efficiently extracting ions, the ion source is configured to include: a conductive tubular body having an ion emitting aperture in a tip surface thereof and a penetration portion in a side wall thereof allowing thermo-electrons to pass through from an outside toward an inside; a mesh surrounding an outer periphery of the penetration portion; and a thermionic emission filament surrounding an outer periphery of the mesh, such that the thermo-electrons emitted from the thermionic emission filament pass through the mesh and reach the inside of the conductive tubular body through the penetration portion.

The invention relates to a mass spectrometer having an electron impact ionization source which comprises an ejector for forming a beam of sample gas being driven in a first direction through an interaction region; a magnet assembly configured and arranged such that its magnetic field lines pass through the interaction region substantially parallel to the first direction; an electron emitter assembly for directing electrons toward the interaction region in a second direction being aligned substantially opposite to the first direction, wherein the electrons propagate along and are confined about the magnetic field lines until reaching the interaction region and forming sample gas ions therein; and a mass analyzer located downstream from the interaction region to which the sample gas ions are guided for mass analysis.

The present invention relates to an electron bean injection control of a mass spectrometer. A mass spectrometer of the present invention includes: a reference waveform generator configured to generate a reference waveform signal having one type of a square wave and a sine wave, a waveform generator configured to generate a sync signal synchronized with the reference waveform signal; an RF module configured to generate an RF voltage signal from the reference waveform signal and apply the RF voltage signal to an RF electrode in the ion trap, an electron beam generator configured to control an operation of an ultraviolet (UV) diode for generating an electron beam injected into the ion trap according to an input control signal, and a control circuit configured to generate the control signal by using the square wave signal.

An analyzer (1) includes: an ionizer unit (10) that ionizes molecules to be analyzed; a filter unit (20) that selectively passes ions generated by the ionizer unit; and a detection unit (50) that detects ions that have passed the filter unit. The detection unit (50) includes a plurality of detection elements (51) disposed in a matrix, and the analyzer (1) further includes a first reconfiguration unit (83) that switches between detection patterns including detection elements to be enabled for detection out of the plurality of detection elements. The ionizer unit (10) includes a plurality of ion sources (11), and the analyzer (1) further includes a driving control unit (65) that switches the connections of the plurality of ion sources based on changes in characteristics of the ion sources.

In order to attain a main objective of the present invention to provide an ion source capable of efficiently extracting ions, the ion source is configured to include: a conductive tubular body having an ion emitting aperture in a tip surface thereof and a penetration portion in a side wall thereof allowing thermo-electrons to pass through from an outside toward an inside; a mesh surrounding an outer periphery of the penetration portion; and a thermionic emission filament surrounding an outer periphery of the mesh, such that the thermo-electrons emitted from the thermionic emission filament pass through the mesh and reach the inside of the conductive tubular body through the penetration portion.

For improving sensitivity, dynamic range, and specificity of GC-MS analysis there are disclosed embodiments of novel apparatuses based on improved characteristics of semi-open source with electron impact ionization, providing much higher brightness compared to known open EI sources. In an implementation, the source becomes compatible with multi-reflecting TOF analyzers for higher resolution analysis for improving detection limit. With improved schemes of spatial and temporal refocusing there are proposed various tandem TOF-TOF spectrometers with PSD, CID, and SID fragmentation and using either singly reflecting TOF or MR-TOF analyzers.

In an ion source 3 in which a repeller electrode 32 for forming a repelling electric field that repels ions toward an ion emission port 311 is provided inside of an ionization chamber 31, ion focusing electrodes 36 and 37 are respectively arranged between an electron introduction port 312 and a filament 34 and between an electron discharge port 313 and a counter filament 35. An electric field formed by applying a predetermined voltage to each of the ion focusing electrodes 36 and 37 intrudes into the ionization chamber 31 through the electron introduction port 312 and the electron discharge port 313, and becomes a focusing electric field that pushes the ions in an ion optical axis C direction. Ions at positions off a central part of the ionization chamber 31 receive the combined force of the force of the repelling electric field and the force of the focusing electric field, and move toward the ion emission port 311 while approaching the ion optical axis C. Accordingly, the amount of ions sent out from the ion emission port increases. Further, even if a charge-up phenomenon occurs, the ion trajectories less easily change, and the stability of the sensitivity can be enhanced.

According to one embodiment of the present invention, an ion source includes: an anode tube in which gas flowing in through one side is ionized and discharged to the other side and in which a slit is formed on the outer circumference thereof; a filament which emits thermal electrons toward the slit so as to ionize the gas; and a diffusion-preventing body arranged between the filament and the slit and having at least one hole through which the thermal electrons can pass so as to reduce the diffusion of the thermal electrons flowing into the anode tube.