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.

A time-of-flight mass spectrometer (1) comprises an ion source a segmented linear ion device (10) for receiving sample ions supplied by the ion source and a time-of-flight mass analyzer for analyzing ions ejected from the segmented device. A trapping voltage is applied to the segmented device to trap ions initially into a group of two or more adjacent segments and subsequently to trap them in a region of the segmented device shorter than the group of segments. The trapping voltage may also be effective to provide a uniform trapping field along the length of the device (10).

An orthogonal pulse accelerator for a Time-of-Flight mass analyzer includes an electrically-conductive first plate extending in a first plane, and a second plate spaced from the first plate. The second plate includes a grid that defines a plurality of apertures each having a first dimension extending in a first direction and a second dimension orthogonal to the first dimension, the first and second dimensions lying in the second plane and the second dimension begin larger than the first dimension. The first and second plates are positioned in the Time-of-Flight mass analyzer to receive, during operation of the mass analyzer, an ion beam propagating in the first direction in a region between the first and second plates, and the orthogonal pulse accelerator directs ions in the ion beam through the apertures.

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.

Systems and methods are disclosed for dynamically switching an ion guide and a TOF mass analyzer between concentrating or not concentrating ions in a targeted acquisition. Product ions are ejected from the ion guide into the TOF mass analyzer and the intensity of a known product ion is measured at two or more time steps. The ion guide initially ejects product ions using a sequential or Zeno pulsing mode that concentrates product ions with different m/z values within the TOF mass analyzer at the same time. If the intensity of the product ion is increasing and greater than a threshold intensity, the ion guide switches to a continuous or normal pulsing mode that does not concentrate ions with different m/z values in the TOF mass analyzer at the same time. Similarly, if the intensity decreases below a threshold in continuous mode, the ion guide switches back to sequential mode.

A method of mass spectrometry is disclosed comprising providing a flight region for ions to travel through and a detector or fragmentation device. A potential profile is maintained along the flight region such that ions travel towards the detector or fragmentation device. The potential at which a first length of the flight region is maintained is then changed from a first potential to a second potential while at least some ions are travelling within the first length of flight region. The changed potential provides a first potential difference at an exit of the length of flight region, through which the ions are accelerated as they leave the length of flight region. This increases the kinetic energy of the ions prior to them reaching the detector or fragmentation cell.

An ion accelerator for a time-of-flight mass spectrometer includes a pulsed ion accelerator positioned proximate to a sample plate and having an electrode that is electrically connected to the sample plate. An accelerator power supply generates an accelerating potential on the ion accelerator electrode that accelerates a pulse of ions generated from the sample positioned on the sample plate. An ion focusing electrode is positioned after the pulsed ion accelerator. A potential applied to the ion focusing electrode focuses the pulse of ions into a substantially parallel beam propagating in an ion flight path. A static ion accelerator is positioned proximate to the ion focusing electrode with an input that receives the pulse of ions focused by the ion focusing electrode. The static ion accelerator accelerating the focused pulse of ions.

An ion mobility gas detector apparatus including a detector core, an inlet gas path, an exhaust gas path, a source of diluent gas, and at least one or more sensors for measuring temperature, pressure and humidity of gas streams. Further included is a mixing mechanism adapted to mix at least first and second gas streams in response to one or more sensor measurements. A controller is provided for applying drive signals to the detector core.

A flight-of-time mass spectrometer is offered which can provide a variable range of collisional energies that can be made wider than heretofore. Also, a method of controlling this spectrometer is offered. The spectrometer has an ion source, a first mass analyzer, an ion gate, a potential lift, a collisional cell, a second mass analyzer, a detector, and a potential control portion for controlling the potential on the potential lift. When the precursor ions selected by the ion gate enter the potential lift, the potential control portion sets the potential on the conductive box at V.sub.1. When the potential on the potential lift is varied, the potential control portion varies the potential on the potential lift from V.sub.1 to V.sub.2 while precursor ions are traveling through the potential lift.

MALDI-TOF MS systems have solid state lasers and successive and varied delay times between ionization and acceleration (e.g. extraction) to change focus masses during a single sample signal acquisition without requiring tuning of the MS by a user. The (successive) different delay times can change by 1 ns to about 500 ns, and can be in a range that is between 1-2500 nanoseconds.