A mass analyzer includes a mass analyzing magnet that applies a magnetic field to ions extracted from an ion source to deflect the ions, a mass analyzing slit that is provided downstream of the mass analyzing magnet and allows an ion of a desired ion species among the deflected ions to selectively pass, and a lens device that is provided between the mass analyzing magnet and the mass analyzing slit and applies a magnetic field and/or an electric field to the ion beam to adjust the convergence or divergence of a ion beam. The mass analyzer changes a focal point of the ion beam in a predetermined adjustable range between an upstream side and a downstream side of the mass analyzing slit with the lens device to adjust mass resolution.

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.

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.

A method of static gas mass spectrometry is provided. The method includes the steps of: introducing a sample gas comprising two or more isotopes to be analyzed into a static vacuum mass spectrometer at a time, t.sub.0; operating an electron impact ionization source of the mass spectrometer with a first electron energy below the ionization potential of the sample gas for a first period of time that is following t.sub.0 until a time t.sub.1; and operating the electron impact ionization source with a second electron energy at least as high as the ionization potential of the sample gas for a second period of time that is after time t.sub.1. The first time period from t.sub.0 to t.sub.1 is a period corresponding to a period taken for the isotopes of the sample gas to equilibrate in the mass spectrometer. A constant ion source temperature is preferably maintained. Also provided is a static gas mass spectrometer.

A method of static gas mass spectrometry is provided. The method includes the steps of: introducing a sample gas comprising two or more isotopes to be analyzed into a static vacuum mass spectrometer at a time, t.sub.0; operating an electron impact ionization source of the mass spectrometer with a first electron energy below the ionization potential of the sample gas for a first period of time that is following t.sub.0 until a time t.sub.1; and operating the electron impact ionization source with a second electron energy at least as high as the ionization potential of the sample gas for a second period of time that is after time t.sub.1. The first time period from t.sub.0 to t.sub.1 is a period corresponding to a period taken for the isotopes of the sample gas to equilibrate in the mass spectrometer. A constant ion source temperature is preferably maintained. Also provided is a static gas mass spectrometer.

A control system for controlling a magnet of a magnetic sector mass spectrometer comprises a magnetic field sensor for sensing the magnetic field of the magnet and generating an output representative thereof; a set point generator configured to generate an output representative of, or related to, a desired magnetic field of the magnet; and a digital controller configured to receive a variable digital input signal from the output of the magnetic field sensor and a set point digital input signal from the output of the set point generator, and to generate a digital output from which is derived a control signal for controlling a current to the magnet so as to control the magnetic field thereof. The control system is arranged to apply to the digital controller a selected one of a plurality of different controller settings, in accordance with the desired magnetic field of the magnet.

A control system for controlling a magnet of a magnetic sector mass spectrometer comprises a magnetic field sensor for sensing the magnetic field of the magnet and generating an output representative thereof; a set point generator configured to generate an output representative of, or related to, a desired magnetic field of the magnet; and a digital controller configured to receive a variable digital input signal from the output of the magnetic field sensor and a set point digital input signal from the output of the set point generator, and to generate a digital output from which is derived a control signal for controlling a current to the magnet so as to control the magnetic field thereof. The control system is arranged to apply to the digital controller a selected one of a plurality of different controller settings, in accordance with the desired magnetic field of the magnet.

A particle beam device including a magnet, the device including: a particle beam source configured to emit electron and ion beams; a plurality of yokes arranged in a substantially rectangular shape; a coil set including a plurality of coils, wherein windings of the plurality of coils are uniformly distributed across and wound around the plurality of yokes, wherein the coil set is configured to produce both dipole and quadrupole fields, wherein the magnet is configured to deflect and focus electron and ion beams.

A control system for controlling a magnet of a magnetic sector mass spectrometer comprises a magnetic field sensor for sensing the magnetic field of the magnet and generating an output representative thereof; a set point generator configured to generate an output representative of, or related to, a desired magnetic field of the magnet; and a digital controller configured to receive a variable digital input signal from the output of the magnetic field sensor and a set point digital input signal from the output of the set point generator, and to generate a digital output from which is derived a control signal for controlling a current to the magnet so as to control the magnetic field thereof. The control system is arranged to apply to the digital controller a selected one of a plurality of different controller settings, in accordance with the desired magnetic field of the magnet.

A control system for controlling a magnet of a magnetic sector mass spectrometer comprises a magnetic field sensor for sensing the magnetic field of the magnet and generating an output representative thereof; a set point generator configured to generate an output representative of, or related to, a desired magnetic field of the magnet; and a digital controller configured to receive a variable digital input signal from the output of the magnetic field sensor and a set point digital input signal from the output of the set point generator, and to generate a digital output from which is derived a control signal for controlling a current to the magnet so as to control the magnetic field thereof. The control system is arranged to apply to the digital controller a selected one of a plurality of different controller settings, in accordance with the desired magnetic field of the magnet.