The invention relates to optically pumped and pulsed solid-state lasers which are used in mass spectrometers in particular for ionization by matrix-assisted laser desorption (MALDI) and which operate at pulse frequencies of up to 10 kilohertz or even higher. The invention proposes that, instead of interrupting the clocked sequence of the laser operation, individual light pulses or groups of light pulses are blanked out so that subsequent light pulses do not have a higher energy density, in accordance with the requirements for LDI processes. Methods and devices for the blanking out of light pulses are provided which are, in particular, low cost and considerably less complex than other methods.

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.

An analyzer for separating ions according to their time of flight comprising two opposing ion mirrors abutting at a first plane, each mirror comprising inner and outer field-defining electrode systems elongated along an analyzer axis, the outer field-defining electrode system surrounding the inner field-defining electrode system. The outer field-defining electrode system of one mirror comprises two sections, the sections abutting at a second plane, comprising a first section between the first plane and the second plane, and a second section adjacent to the first section. The first section has at least a portion which extends radially from the analyzer axis a greater extent than an adjacent portion of the second section at the second plane. The outer field-defining electrode system comprises an exit port and the analyzer comprises a detector located downstream of the exit port.

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 mass analyser is disclosed comprising an annular ion guide comprising a first annular ion guide section and a second annular ion guide section, wherein the annular ion guide comprises: (i) an inner cylindrical electrode arrangement which is axially segmented and comprises a plurality of first electrodes and (ii) an outer cylindrical electrode arrangement which is axially segmented and comprises a plurality of second electrodes. Ions are introduced into the first annular ion guide section so that the ions form substantially stable circular orbits. Ions are orthogonally accelerated from the first annular ion guide section into the second annular ion guide section and one or more parabolic DC potentials are maintained along a portion of the second annular ion guide section so that ions undergo simple harmonic motion. An inductive ion detector is arranged and adapted to detect ions within the second annular ion guide section.

Apparatuses (41, 91, 111, 115, 121, 151) and methods (31) for time-of-flight mass spectrometry providing effective pulsed conversion of continuous ion beams into pulsed ion packets is disclosed. Bunching of energetic continuous ion beams forms ion packets, which are filtered by a subsequent isochronous energy filter (49, 79, 81-84, 110). The bunching method is particularly suitable for ion sources with relatively large spatial emittance, otherwise unable to fir the acceptance of orthogonal accelerators. The method is particularly suitable for multi-reflecting TOF MS, which accommodates small size ion packets and where the duty cycle advantage of orthogonal accelerators is minor.

There is proposed a right angle time-of-flight detector (41, 117, 124, 143, 144, 145) comprising a conductive converter (46) for emitting and accelerating secondary electrons, a magnetic field formed by at least one magnet (47) for deflecting the secondary electrons at a right angle and a sealed photo-multiplier (26). The detector is expected to provide an extended resource and dynamic range and may be fit into tight assemblies, such as MR-TOF MS.

An instrument for analyzing ions may include an ion source to generate ions, at least one ion processing instrument to process the generated ions by one or both of filtering the ions according to a molecular characteristic and dissociating the ions, and an electrostatic linear ion trap (ELIT) to receive and trap ions exiting the at least one ion processing instrument. The ELIT has first and second ion mirrors separated by a charge detection cylinder, and is configured such that trapped ions oscillate back and forth through the charge detection cylinder between the first and second ion mirrors with a duty cycle, corresponding to a ratio of time spent by the trapped ions traversing the charge detection cylinder and total time spent by the trapped ions traversing a combination of the first and second ion mirrors and the charge detection cylinder during one complete oscillation cycle, of approximately 50%.

A method of targeted mass spectrometric analysis is provided for analyzing trace compounds at sub-ppb level compared to sample matrix. Sample is chromatographically separated at standard conditions to employ a map of target mass (M) versus retention time (RT). Small mass ions under M(RT) are rejected by RF field, and remaining ions are accumulated for pulsed injection into a multi-reflecting TOF MS, either directly from EI source, or from linear RF trap or via a heated RF only quadrupole with axial ion trapping. In combination with EI source the method provides sub femtogram sensitivity at matrices loads in microgram range.

A mass spectrometry system is configured to perform MS.sup.n mass spectrometry, where n is greater than or equal to 3. The mass spectrometry system comprises: a first mass filter having a first maximum resolution; a first fragmentation device downstream of the first mass filter and configured to fragment ions received from the first mass filter; a second mass filter downstream of the first fragmentation device, the second mass filter having a second maximum resolution that is lower than the first maximum resolution; a second fragmentation device downstream of the second mass filter; and a first mass analyser downstream of the second fragmentation device.