An electrostatic trap such as an orbitrap is disclosed, with an electrode structure. An electrostatic trapping field of the form U(r, , z) is generated to trap ions within the trap so that they undergo isochronous oscillations. The trapping field U(r, , z) is the result of a perturbation W to an ideal field U(r, , z) which, for example, is hyperlogarithmic in the case of an orbitrap. The perturbation W may be introduced in various ways, such as by distorting the geometry of the trap so that it no longer follows an equipotential of the ideal field U(r, , z), or by adding a distortion field (either electric or magnetic). The magnitude of the perturbation is such that at least some of the trapped ions have an absolute phase spread of more than zero but less than 2 radians over an ion detection period T.sub.m.

A relatively compact dual ion composition instrument and associated methodology for measuring plasma and ion populations in a variety of interplanetary and planetary environments. The unitary device can measure mass and ionic charge state compositions and 3D velocity distributions of 10 eV/q to 40 keV/q plasma and pick-up ions; and (2) mass composition, energy spectra and angular distributions of 30 keV to 10 MeV energetic ions.

A mass analyser comprises a pair of electrode arrays. Each array has a set of focusing electrodes which are supplied, in use, with voltage to create an electrostatic field in a space between the electrode arrays causing ions to undergo periodic, oscillatory motion in the space, ions passing between electrodes of the sets of focusing electrodes and being repeatedly focused at a centre plane, mid-way between the electrode arrays. At least one electrode of each set of focusing electrodes has an electrode surface closer to the centre plane than the electrode surfaces of other electrodes of the same set. The analyser may be an ion trap mass analyser or a multi-turn ToF mass analyser.

On field ionization under ambient conditions is described and applied on both ionization and desorption of various chemicals and biochemical present on the surface of materials in solid, liquid or gas states. The Atmospheric Pressure Megavolt Electrostatic Field Ionization Desorption (APME-FID) method generates ions directly from the surface of samples connected to a high electrical voltage at megavolt conditions. Megavolt electrostatic potential is generated and gradually accumulated directly on the sample surface by a Van de Graaff generator without causing damage to the sample. Therefore, when coupled with mass spectrometric system, the APME-FID-MS method enables direct detection of analytes on the surface of samples in different sizes and diverse types.

An electrostatic analyzer including at least one first set of electrodes, at least one second set of electrodes, and a field free space separating the two sets of electrodes is disclosed. The two sets of electrodes form two-dimensional electrostatic fields of ion mirrors and are arranged to provide isochronous ion oscillations in an x-y plane. Both sets of electrodes are curves at a constant curvature radius R along a third locally orthogonal Z-direction to form a torroidal field region. A related method is also disclosed.

A monitoring system detects and measures a quantity of radical particles within a gas. A test chamber is coupled to a flow channel that transmits a gas. The test chamber defines an aperture connecting the test chamber and the flow channel, and the aperture permits a subset of the gas to enter the test chamber from the flow channel. An ionizer is positioned within the test chamber and generates radical ions from radical particles of the subset of the gas. A mass spectrometer measures a quantity of the radical ions, thereby providing a measurement of the radical particles in the gas.

An electrostatic trap such as an orbitrap is disclosed, with an electrode structure. An electrostatic trapping field of the form U(r, , z) is generated to trap ions within the trap so that they undergo isochronous oscillations. The trapping field U(r, , z) is the result of a perturbation W to an ideal field U(r, , z) which, for example, is hyperlogarithmic in the case of an orbitrap. The perturbation W may be introduced in various ways, such as by distorting the geometry of the trap so that it no longer follows an equipotential of the ideal field U(r, , z), or by adding a distortion field (either electric or magnetic). The magnitude of the perturbation is such that at least some of the trapped ions have an absolute phase spread of more than zero but less than 2 radians over an ion detection period T.sub.m.

Mass analyzers and methods of ion detection for a mass analyzer are provided. An electrostatic field generator provides an electrostatic field causing ion packets to oscillate along a direction. A pulse transient signal is detected over a time duration that is significantly shorter than a period of the ion oscillation or using pulse detection electrodes having a width that is significantly smaller than a span of ion harmonic motion. A harmonic transient signal is also detected. Ion intensity with respect to mass-to-charge ratio is then identified based on the pulse transient signal and the harmonic transient signal.

In one aspect of the invention, an ion trap mass analyzer includes a variable- or multi-potential type ion guide (MPIG) assembly which has been pre-configured to produce a parabolic-type potential field. Each MPIG electrode has a resistive coating of designed characteristics. In one example the coating varies in thickness along the length of an underlying uniform substrate. The MPIG assembly can be a single MPIG electrode or an array of a plurality of MPIG electrodes. An array can facilitate delocalization for improved performance. This chemical modification of a uniform underlying substrate promotes cheaper and flexible instruments. The modified MPIG electrodes also allow miniaturization (e.g. micro and perhaps even nano-scale), which allows miniaturization of the instrument in which the single or plural modified MPIG electrode(s) are placed. This promotes portability and field use instead of limitation to laboratory settings.

A method of ejecting ions to be analyzed from a quadrupole ion trap in which a trapping field is created by one or more RF voltages applied to one or more electrodes of the trap, the method comprising the steps of cooling the ions to be analyzed within the quadrupole ion trap until the ions are thermalized, reducing the amplitude of one or more RF voltages applied to the quadrupole ion trap and applying the reduced amplitude RF voltages for one half cycle after the one or more RF voltages have reached a zero crossing point, turning off the RF voltages applied to the quadrupole ion trap, and ejecting the ions to be analyzed from the quadrupole ion trap.