An orthogonal acceleration time-of-flight mass spectrometer (1) includes: an ion ejector (123) which ejects measurement-target ions in a predetermined direction; an orthogonal accelerator (132) which accelerates ions in a direction orthogonal to the direction in which the ions are ejected; a ring electrode (131) located between the ion ejector and the orthogonal accelerator, the ring electrode having an opening for allowing ions to pass through and arranged so that the central axis (C2) of the opening is shifted from the central axis (C1) of the ion ejector in a direction along the axis of the acceleration of the ions by the orthogonal accelerator; a reflectron electrode (134) which creates a repelling electric field for reversing the direction of the ions accelerated by the orthogonal accelerator; and an ion detector (135) which detects ions after the direction of flight of the ions is reversed by the reflectron electrode.

Improved pulsed ion sources and pulsed converters are proposed for multi-pass time-of-flight mass spectrometer, either multi-reflecting (MR) or multi-turn (MT) TOF. A wedge electrostatic field (45) is arranged within a region of small ion energy for electronically controlled tilting of ion packets (54) time front. Tilt angle of time front (54) is strongly amplified by a post-acceleration in a flat field (48). Electrostatic deflector (30) downstream of the post-acceleration (48) allows denser folding of ion trajectories, whereas the injection mechanism allows for electronically adjustable mutual compensation of the time front tilt angle, i.e. =0 for ion packet in location (55), for curvature of ion packets, and for the angular energy dispersion. The arrangement helps bypassing accelerator (40) rims, adjusting ion packets inclination angles .sub.2 and what is most important, compensating for mechanical misalignments of the optical components.

Improved ion mirrors (30) (FIG. 3) are proposed for multi-reflecting TOF MS and electrostatic traps. Minor and controlled variation by means of arranging a localized wedge field structure (35) at the ion retarding region was found to produce major tilt of ion packets time fronts (39). Combining wedge reflecting fields with compensated deflectors is proposed for electrically controlled compensation of local and global misalignments, for improved ion injection and for reversing ion motion in the drift direction. Fine ion optical properties of methods and embodiments are verified in ion optical simulations.

Improved ion mirrors (10) are proposed for multi-reflecting TOF MS and electrostatic traps at various analyzer topologies. Ion mirrors (10) are constructed of printed circuit boards (11) with improved precision and flatness. To compensate for the remaining geometrical imperfections of mirror electrodes there are proposed electrode sets (17) and field structures in the ion retarding region for electronically adjusting of the ion packets time fronts, for improving the ion injection into the analyzer and for reversing the ion motion in the drift direction.

A mass spectrometer comprising: a pulsed ion source for generating pulses of ions having a range of masses; a time-of-flight mass analyzer for receiving and mass analyzing the pulses of ions from the ion source; and an energy controlling electrode assembly located between the pulsed ion source and the time-of-flight mass analyzer configured to receive the pulses of ions from the pulsed ion source and apply a time-dependent potential to the ions thereby to control the energy of the ions depending on their m/z before they reach the time-of-flight mass analyzer. Mass dependent differences in average energy of ions can be reduced for injection into a time-of-flight mass analyzer, which can improve ion transmission and/or instrument resolving power.

The present invention provides a time-of-flight mass spectrometer (TOFMS) taken measures for preventing a deterioration in accuracy caused at the time of transportation to an installation site. A time-of-flight mass spectrometer (TOFMS) for performing mass separation based on the time of flight of an ion flying in a flight space includes an ion transportation unit (12, 14, 15) configured to transport an ion, an acceleration unit (expulsion electrode (161) and the like) configured to receive the ion transported by the ion transportation unit and accelerate the ion to introduce the ion into the flight space, a flight unit incorporating the flight space, a first vacuum vessel (18A) enclosing the ion transportation unit, the acceleration unit, and at least a part of the flight unit, a chassis (19) on which the first vacuum vessel (18A) is placed, and a reflector unit (20) to which a reflector (reflection (164)) and a second vacuum vessel (28) are fixed, the reflection (164) being configured to reverse the flight trajectory of the ion accelerated by the acceleration unit and introduced into the flight space, and the second vacuum vessel (28) being attachable to an end of the first vacuum vessel (18A) and enclosing the reflector. Since the reflector unit (20) is separated from other parts during transportation, the other parts are easily moved by, for example, casters (191) disposed on the chassis (19), and the reflector unit (20) is moved without being affected by the vibrations caused by the movement on the casters (191).

Two-channel electrical and photo-electrical TOF ion detection systems are provided. These systems maintain the resolution and dynamic range advantages of four-channel systems but at a lower cost. Electrodes or light pipes are configured to direct electrons or photons produced by ion impacts into two separate channels. The first channel receives electrons or photons resulting from the inner or central part of the rectangular pattern of each ion impact. The second channel receives electrons or photons resulting from the two outer ends of the rectangular pattern of each ion impact. In a two-channel digitizer, the first channel and the second channel are independently calibrated to align the first digital value and the second digital value in time and account for the convex shape of the ion impacts of each ion packet and/or the curvature of a microchannel plate.

A method of time-of-flight mass spectrometry is disclosed comprising: providing two ion mirrors (42) that are spaced apart in a first dimension (X-dimension) and that are each elongated in a second dimension (Z-dimension) orthogonal to the first dimension; introducing packets of ions (47) into the space between the mirrors using an ion introduction mechanism (43) such that the ions repeatedly oscillate in the first dimension (X-dimension) between the mirrors (42) as they drift through said space in the second dimension (Z-dimension); oscillating the ions in a third dimension (Y-dimension) orthogonal to both the first and second dimensions as the ions drift through said space in the second dimension (Z-dimension); and receiving the ions in or on an ion receiving mechanism (44) after the ions have oscillated multiple times in the first dimension (X-dimension); wherein at least part of the ion introduction mechanism (43) and/or at least part of the ion receiving mechanism (44) is arranged between the mirrors (42).

A mass spectrometer comprising: a pulsed ion source for generating pulses of ions having a range of masses; a time-of-flight mass analyzer for receiving and mass analyzing the pulses of ions from the ion source; and an energy controlling electrode assembly located between the pulsed ion source and the time-of-flight mass analyzer configured to receive the pulses of ions from the pulsed ion source and apply a time-dependent potential to the ions thereby to control the energy of the ions depending on their m/z before they reach the time-of-flight mass analyzer. Mass dependent differences in average energy of ions can be reduced for injection into a time-of-flight mass analyzer, which can improve ion transmission and/or instrument resolving power.

The present invention provides a time-of-flight mass spectrometer (TOFMS) taken measures for preventing a deterioration in accuracy caused at the time of transportation to an installation site. A time-of-flight mass spectrometer (TOFMS) for performing mass separation based on the time of flight of an ion flying in a flight space includes an ion transportation unit (12, 14, 15) configured to transport an ion, an acceleration unit (expulsion electrode (161) and the like) configured to receive the ion transported by the ion transportation unit and accelerate the ion to introduce the ion into the flight space, a flight unit incorporating the flight space, a first vacuum vessel (18A) enclosing the ion transportation unit, the acceleration unit, and at least a part of the flight unit, a chassis (19) on which the first vacuum vessel (18A) is placed, and a reflector unit (20) to which a reflector (reflection (164)) and a second vacuum vessel (28) are fixed, the reflection (164) being configured to reverse the flight trajectory of the ion accelerated by the acceleration unit and introduced into the flight space, and the second vacuum vessel (28) being attachable to an end of the first vacuum vessel (18A) and enclosing the reflector. Since the reflector unit (20) is separated from other parts during transportation, the other parts are easily moved by, for example, casters (191) disposed on the chassis (19), and the reflector unit (20) is moved without being affected by the vibrations caused by the movement on the casters (191).