An ion source for a mass spectrometer and a method for providing ions from a sample material

Abstract

An ion source 100 for a mass spectrometer 10 having a support 110 for a sample plate 120 on which a sample material is provided, a light source 130 configured to ionise the sample material, an actuato

Description

Technical Field

[0001] The present disclosure relates to an ion source for a mass spectrometer for providing ions from a sample material on a sample plate, a computer program configured to be executed by a controller of the ion source, and a method for providing ions from a sample material. Background

[0002] Mass spectrometers may be used to determine a signature (i.e., the content) of a sample. Samples are often ionised to determine the signature.

[0003] A sample may be ionised by emitting light from a laser at the sample. Detection of the ions from the sample may be used to generate a spectrum. The spectrums generated using current techniques are often grainy (i.e., have low resolution) and / or have a high signal to noise ratio.

[0004] Emitting light to the same region of a sample continuously may deplete the sample.

[0005] Emitting light to discreet (non-overlapping) regions of a sample requires the sample to move relative to the laser. Synchronising emitting light from the laser and the movement of the laser and / or sample is complex. This can be particularly complex when achieving a high laser firing rate (e.g., to reduce the time required to generate a spectrum from a sample) whilst providing a spectrum of similar or better quality.

[0006] It is an object of the present disclosure to solve one or more of the above-mentioned problems. Summary

[0007] Some, not necessarily all, embodiments of the present disclosure relate to an ion source for a mass spectrometer for providing ions from a sample material on a sample plate, the ion source comprising: a support arranged to support the sample plate; a light source configured to emit light to a region of the sample plate for ionising the sample material; an actuator configured to move the support relative to the light source; and a controller configured to cause: the light source to emit light to a first region of the sample plate; the actuator to move the support relative to the light source such that the light source is configured to emit light to a second region of the sample plate, the second region overlapping the first region; and the light source to emit light to the second region.

[0008] The support being arranged to support the sample plate may enable the sample plate to be supported when the light source emits light at the sample plate.

[0009] The support may be a stage.

[00010] The light source being configured to emit light to a region of the sample plate may enable a sample material on the plate to be ionised by the emitted light.

[00011] The actuator being configured to move the support relative to the light source (e.g., by moving the support and / or the light source) may enable the light source to emit light to a plurality of regions (e.g., the first and second regions).

[00012] The controller being configured to cause the light source to emit light to a first region of the sample plate may enable a sample material at the first region to be ionised.

[00013] The controller being configured to cause the actuator to move the support relative to the light source such that the light source is configured to emit light to a second region of the sample plate enables the light source to emit light to the second region.

[00014] The second region overlapping the first region (e.g., rather than being discreet regions) reduces the complexity of synchronising the light source emitting light and the relative movement of the light source and / or the support. For example, the distance that the light source and / or the support are required to move may be reduced (e.g., in comparison to discreet regions).

[00015] The inventor has found that the second region overlapping the first region may allow the light source to emit light more frequently (e.g., in comparison to discreet regions).

[00016] The actuator may be configured to move the support relative to the light source such that a diameter of the first region and a diameter of the second region overlap by at least 1.5% of the diameter of the first and second regions.

[00017] The actuator may be configured to move the support relative to the light source such that the diameter of the first region and the diameter of the second region overlap by at least 2.75% of the diameter of the first and second regions.

[00018] The actuator may be configured to move the support relative to the light source such that the diameter of the first region and the diameter of the second region overlap by less than or equal to 98.5%.

[00019] The actuator may be configured to move the support relative to the light source less than 300pm. The actuator may be configured to move the support relative to the light source less than 100pm. The actuator may be configured to move the support relative to the light source less than 10pm such as 2.9pm or 1.6pm.

[00020] The second region may only partially overlap the first region.

[00021] The controller may be configured to cause the actuator to move the support relative to the light source such that the light source is configured to emit light to N regions of a sample zone of the sample plate, wherein N is a natural number greater than or equal to 2.

[00022] In some examples 2 <N <1500. In some examples 2 <N <500. In some examples, 20 <N <70. In some examples, N is 35. In some examples, N is 64. In some examples, N is 1200.

[00023] The actuator may be configured to move the support relative to the light source in a linear path. The actuator being configured to move the support relative to the light source in a linear path may reduce the complexity of synchronising light being emitted from the light source and the relative movement of the light source and support. For example, the actuator may only comprise a single linear actuator.

[00024] The actuator may be configured to discretely move the support relative to the light source.

[00025] The actuator may be configured to continuously move the support relative to the light source. The actuator being configured to continuously move the support relative to the light source may enable light to be emitted to the first and second regions while the light source and / or the support are moving.

[00026] The actuator may be configured to move the support. The actuator may comprise an electrical actuator (e.g., one or more electric motors).

[00027] The actuator may be configured to move the support relative to the light source at a speed of less than 5 x 10'3 m s’1. The speed may be in a range from 1 x 10'3 m s-1 to 3 x 10'3 m s’1. The speed may be 1.56 x 10'3 m s’1. The speed may be 2.86 x 10'3 m s’1.

[00028] The light source may be configured to emit one or more pulses of light.

[00029] The light source may be configured to emit one or more pulses of light at a frequency of greater than or equal to 200Hz. The frequency of the light source may be the rate at which pulses of light are emitted from the light source (e.g., rather than the frequency of the light itself). The light source may be configured to emit one or more pulses of light at a frequency of greater than or equal to 450Hz. The light source may be configured to emit one or more pulses of light at a frequency of greater than or equal to 900Hz. The light source may be configured to emit light at a frequency of 200Hz, 470Hz, 510Hz, 860Hz, 1000Hz and / or 2000Hz.

[00030] The light source may comprise a laser.

[00031] The light source may be configured to emit continuous and / or pulsed light.

[00032] The region may be a circular region. The region may comprise a diameter of 100pm.

[00033] The ion source may comprise the sample plate.

[00034] Some, not necessarily all, embodiments of the present disclosure relate to a mass spectrometer comprising the ion source according to any preceding paragraph.

[00035] The mass spectrometer may comprise a matrix-assisted laser desorption ionisation (MALDI) time of flight (TOF) mass spectrometer.

[00036] Some, not necessarily all, embodiments of the present disclosure relate to a computer program configured to be executed by the controller according to any preceding paragraph, the computer program configured to cause the controller to cause: the light source to emit light to a first region of the sample plate; the actuator to move the support relative to the light source such that the light source is configured to emit light to a second region of the sample plate, the second region overlapping the first region; and the light source to emit light to the second region.

[00037] Some, not necessarily all, embodiments of the present disclosure relate to a method for providing ions from a sample material, the method comprising: ionising, by a light source, the sample material at a first region; moving the light source relative to the sample region such that the light source is configured to emit light to a second region overlapping the first region; and ionising, by the light source, the sample material at the second region.

[00038] Moving the light source relative to the sample region may comprise moving the light source relative to the sample region such that a diameter of the first region and a diameter of the second region overlap by at least 1.5% of the diameter of the first and second regions.

[00039] Moving the light source relative to the sample region may comprise moving the light source relative to the sample region such that a diameter of the first region and a diameter of the second region overlap by at least 2.75% of the diameter of the first and second regions.

[00040] Moving the light source relative to the sample region may comprise moving the light source relative to the sample region such that the diameter of the first region and the diameter of the second region overlap by less than or equal to 98.5%.

[00041] Moving the light source relative to the sample region may comprise moving the support relative to the light source less than 300pm. Moving the light source relative to the sample region may comprise moving the support relative to the light source less than 100pm. Moving the light source relative to the sample region may comprise moving the support relative to the light source less than 10pm such as 2.9pm or 1.6pm.

[00042] The second region may only partially overlap the first region.

[00043] The method may comprise causing the actuator to move the support relative to the light source such that the light source is configured to emit light to N regions of a sample zone of the sample plate, wherein N is a natural number greater than or equal to 2.

[00044] In some examples 2 <N <1500. In some examples 2 <N <500. In some examples, 20 <N <70. In some examples, N is 35. In some examples, N is 64. In some examples, N is 1200.

[00045] Moving the light source relative to the sample region may comprise moving the support relative to the sample region in a linear path.

[00046] Moving the light source relative to the sample region may comprise continuously or discreetly moving the light source relative to the sample region.

[00047] Moving the light source relative to the sample region may comprise moving the support relative to the sample region at a speed of less than 5 x 10'3 m s’1. The speed may be in a range from 1 x 10'3 m s-1 to 3 x 10'3 m s’1. The speed may be 1.56 x 10'3 m s’1. The speed may be 2.86 x 10'3 m s’1.

[00048] Ionising may comprise the light source emitting one or more pulses of light at the sample region (e.g., the first sample region, the second sample region etc.).

[00049] The light source may emit one or more pulses of light at a frequency of greater than or equal to 200Hz. The light source may emit one or more pulses of light at a frequency of greater than or equal to 450Hz. The light source may emit one or more pulses of light at a frequency of greater than or equal to 900Hz. The light source may emit light at a frequency of 200Hz, 470Hz, 510Hz, 860Hz, 1000Hz and / or 2000Hz.

[00050] The light source may comprise a laser. The light source may emit continuous and / or pulsed light.

[00051] The region may be a circular region. The region may comprise a diameter of 100pm. Brief Description of the Drawings

[00052] Some examples will now be described with reference to the accompanying drawings in which: FIG. 1 shows a schematic of an example ion source; FIG. 2 shows a schematic of an example mass spectrometer comprising an example ion source; FIG. 3 shows a schematic of some functional components of an example ion source and a detector; FIG. 4 shows an example sample plate; FIGs 5A to 5C show an example sample zone of an example sample plate; and FIG. 6 shows a flowchart of a method for providing ions from a sample material. It should be understood that the drawings are not necessarily to scale. Detailed Description

[00053] FIG. 1 shows a schematic of an example ion source 100 for a mass spectrometer 10.

[00054] The ion source 100 shown in FIG. 1 is for a mass spectrometer 10 (e.g., may be integrated as part of a mass spectrometer 10). The ion source 100 may be for providing one or more ions from a sample material on a sample plate 120 (e.g., to a detector of the mass spectrometer 10). In other words, the ion source 100 may be configured to ionise a sample material located on the sample plate 120.

[00055] In some examples, the mass spectrometer 10 may comprise a TOF mass spectrometer 10 such as a MALDI TOF mass spectrometer 10.

[00056] The ion source 100 comprises a light source 130. The light source 130 is configured to emit light 132 to a region of the sample plate 120 for ionising the sample material. In other words, the light source 130 may be configured to emit light 132 to the region such that at least a portion of a sample material at the region (e.g., within the region) may be ionised (e.g., by the emitted light).

[00057] The arrow denoted by reference sign 132 in FIG. 1 shows an example path of light 132 (e.g., of a light pulse) emitted from the light source 130 and to the sample plate 120.

[00058] The ion source 100 comprises an actuator 140 configured to move the support 110 relative to the light source 130. For example, the actuator 140 may be configured to move the support 110 and / or the light source 130 such that the light source 130 is configured to emit light 132 to a second region of the sample plate 120. The second region of the sample plate 120 overlaps the first region of the sample plate 120.

[00059] The ion source 100 comprises a controller 150 configured to cause the light source to emit light 132 to the first region of the sample plate 120. The controller 150 is configured to cause the actuator 140 to move the support 110 relative to the light source 130 such that the light source 130 is configured to emit light 132 to a second region of the sample plate 120, the second region overlapping the first region. The controller 150 is configured to cause the light source 130 to emit light to the second region.

[00060] The arrow denoted by reference sign 134 in FIG. 1 shows an example ion path 134 provided by the ion source 100. An ion provided by the ion source 100 may be detected by a detector. The detected ions from the sample may be used to generate a spectrum.

[00061] The ion source 100 may be configured to provide any suitable number of ions for detection (e.g., by the detector of the mass spectrometer 10). The detected ions may be used to generate one or more spectrums.

[00062] The ion source 100 comprises a support 110 arranged to support the sample plate 120. The support 110 may comprise a stage.

[00063] The support 110 may comprise one or more fixtures arranged to correspond with one or more fixtures of the sample plate 120. For example, the fixtures may comprise one or more corresponding male and / or female portions. The fixtures may be arranged to fix the sample plate 120 relative to the support 110 (e.g., such that movement of the support 110 causes corresponding movement of the sample plate 120).

[00064] In some examples, the support 110 may comprise the sample plate 120. For example, the sample plate 120 may be integrally formed with the support 110. For example, the sample plate 120 may form an exterior (e.g., upper) surface of the support 110.

[00065] The support 110 may be moveable relative a housing of the ion source 100. The support 110 may be fixed relative to the housing of the ion source 100.

[00066] The sample plate 120 may be arranged to support a sample material. The sample material (i.e., sample) may comprise any substance or composition (i.e., that a user of the ion source 100 would like to determine the contents of). The sample may be fixed in a carrier The carrier may be used to preserve the sample material (e.g., such that the sample material may be subsequently ionised (e.g., efficiently ionised)) The carrier and / or the sample material may develop a chemical alteration of its superficial layer (such as a crust). The crust may be an oxidised layer of the sample material.

[00067] In some examples, the sample material may be Escherichia coli (E. coli), Klebsiella pneumoniae, Klebsiella aerogenes, Proteus mirabilis, Enterococcus faecalis, Staphylococcus aureus, Staphylococcus saprophyticus, Streptococcus mutans, Streptococcus pneumoniae, Streptococcus mitis, Candida albicans, Candida glabrata, Aspergillus fumigatus, Trichophyton interdigitale, and / or Cladosporium. The sample material (e.g., E. coli) may comprise a crust.

[00068] The sample plate 120 (e.g., a sample zone of the sample plate 120) comprises a first region and a second region. The first region and the second region overlap one another. The second region may only partially overlap (i.e., not wholly overlap) the first region.

[00069] In some examples, a diameter of the first region and a diameter of the second region overlap by at least 1.5% of the diameter of the first and second regions. In some examples, the diameter of the first region and the diameter of the second region overlap by at least 2.75% of the diameter of the first and second regions.

[00070] In some examples, the diameter of the first region and the diameter of the second region overlap by less than or equal to 98.5%. In some examples, the diameter of the first region and the diameter of the second region overlap by less than or equal to 97.25%.

[00071] The first region and the second region may be defined by an exterior surface of the sample plate 120 (e.g., an upper surface of the sample plate 120).

[00072] As shown in FIG. 4, the sample plate 120 may comprise one or more sample zones 400 (e.g., sample spot). Each sample zone 400 may comprise one or more regions. For example, as shown in FIGs 5A to 5C, the sample zone 400 may comprise one or more regions 501, 502, 503.

[00073] In some examples, the controller 150 is configured to cause the actuator 140 to move the support 110 relative to the light source 130 such that the light source 130 is configured to emit light to N regions 501, 502, 503 of a sample zone of the sample plate 120, wherein N is a natural number greater than or equal to 2.

[00074] In some examples 2 <N <1000 such as 2 <N <500. In some examples, 20 <N <70. In some examples, N is 35. In some examples, N is 64.

[00075] As shown in FIG. 4, the sample plate 120 may comprise any suitable number of sample zones 400.

[00076] Each region 501, 502, 503 may comprise any suitable shape. In some examples, the shape of each region 501, 502, 503 is (substantially) the same as one another. The shape of the region 501, 502, 503 may be defined by a cross-section of the light emitted from the light source 132. Each region 501, 502, 503 may be a regular shaped region 501, 502, 503 (i.e., each region 501, 502, 503 may be a regular shape). Each region 501, 502, 503 may comprise one or more curved sides. In some examples, each region 501, 502, 503 may be a circular region. The region 501, 502, 503 may comprise a diameter of 100pm.

[00077] In some examples, the ion source 100 may comprise the sample plate 120.

[00078] The light source 130 may be configured to emit one or more pulses of light. Additionally, or alternatively, the light source 130 may be configured to emit continuous light. The light source 130 may comprise a laser. In some examples, the laser may comprise a laser wavelength of 355nm, a pulse energy of 15pJ, a pulse duration of 1.1ns, a peak power of 13.6kW, and an average power at 1kHz of 15mW. In some examples, the laser may comprise a laser wavelength of 343nm, a pulse energy of 100pJ, a pulse duration of 1.0ns, a peak power of 100kW, and an average power at 2kHz of 200mW. In some examples, the laser may comprise a filter (e.g., a density filter) configured to reduce the power of the laser (e.g., to improve the ionisation of a sample material).

[00079] The light source 130 may be configured to emit one or more pulses of light at a frequency of greater than or equal to 450Hz. The frequency of the light source 130 may be the rate at which pulses of light are emitted from the light source 130 (e.g., rather than the frequency of the light itself). For example, a light source 130 emitting light pulses at 450Hz emits 450 pulses of light per second.

[00080] The light source 130 may be configured to emit one or more pulses of light at a frequency of greater than or equal to 200Hz. The light source 130 may be configured to emit one or more pulses of light at a frequency of greater than or equal to 900Hz. The light source 130 may be configured to emit light at a frequency of 200Hz, 470Hz, 510Hz, 860Hz, 1000Hz and / or 2000Hz.

[00081] The actuator 140 may be configured to move the support 110 relative to the light source 130 in a pre-determined path such as a linear path. In some examples, the path may be curved such as a spiral.

[00082] The actuator 140 may be configured to discretely and / or continuously move the support 110 relative to the light source 130.

[00083] The actuator 140 may comprise one or more actuators 140. The actuator 140 may comprise an electrical actuator 140 (e.g., one or more electric motors).

[00084] Moving the support 110 and / or the light source 130 may comprise rotating, panning, tilting, and / or translating the support 110 and / or the light source 130 relative to the other of the support 110 and / or light source 130. In other words, the actuator 140 may be configured to rotate, pan, tilt, and / or translate the support 110 relative to the light source 130.

[00085] In some examples, the actuator 140 is configured to move the support 110 (e.g., only the support 110).

[00086] The actuator 140 may be configured to move (e.g., translate) the support 110 relative to the light source at a speed of less than 5 x 10'3 m s’1. For example, the speed may be in a range from 1 x 10'3 m s-1 to 3 x 10'3 m s’1. The speed may be 1.56 x 10'3 m s’1. The speed may be 2.86 x 10'3 m s’1.

[00087] The controller 150 may be configured to cause the light source 130 to emit a plurality of light pulses at the same region 501, 502, 503 (i.e., before causing the actuator 140 to move the support 110 relative to the light source 130). In some examples, causing the light source 130 to emit a plurality of light pulses in this manner may remove at least part of the carrier of the sample material, thereby enabling the light pulses to ionise the sample material (e.g., directly). The plurality of pulses may be a predetermined number of pulses (e.g., from a user input to the controller 150). During testing, the inventor has found that moving the support 110 relative to the light source 130 at a speed of less than 5 x 10'3 m s-1 may be particularly effective (e.g., when the light source 130 is emitting light at 450Hz or more and for particular carriers).

[00088] The optimum speed may vary depending on the power of the light source 130, the frequency of the light source 130, and / or the carrier (e.g., the carrier thickness and content). The inventor has found that for some carriers and light sources, the number of pulses of light emitted to a first region (i.e. the same region) when moving the light source 130 relative to the support by means of consecutive homogeneously spaced overlapping -)T regions is 3 times the number of pulses of light emitted to a first region (i.e., the same region) without moving the light source 130 relative to the support, in order to irradiate that region with an equivalent amount of average energy.

[00089] FIG. 2 shows an example mass spectrometer 10 comprising an ion source 100 (e.g., the ion source 100 shown in FIG. 1).

[00090] The mass spectrometer 10 comprises an ion guide 210, a detector 220, and a housing 230.

[00091] In some examples, the ion source 100, ion guide 210, and detector 220 may be arranged in series. The arrow denoted by reference sign 134 shown in FIG. 2 shows an example ion path 134 (i.e., from the ion source 100 to the detector 220).

[00092] The housing 230 may be arranged to house one or more other components of the mass spectrometer 10 under vacuum (e.g., in at least a partial vacuum). In the example shown in FIG. 2, the housing 230 is arranged to house the ion source 100, ion guide 210, and detector 220 under vacuum.

[00093] The ion guide 210 may comprise one or more electrodes. The one or more electrodes may be arranged to define at least part of the ion path 134. The one or more electrodes may comprise a set of stacked electrodes. The one or more electrodes may be arranged to have an electrical potential applied to them thereby forming an ion acceleration region for accelerating ions from the ion source 100.

[00094] In some examples, high voltage (HV) electrical connections are made to each electrode through HV vacuum feedthrough pins. An ‘in-vacuum’ interface printed circuit board (PCB) may be arranged to connect the HV vacuum feedthrough pins to their respective electrodes.

[00095] Additionally, or alternatively, the ion guide 210 may comprise an ion optical element such as an Einzel lens. The Einzel lens may be configured to radially focus an ion passing along the axis of the lens (e.g., by varying the potential applied to the Einzel lens).

[00096] The detector 220 may be configured to detect ions. In other words, the detector 220 may comprise an ion detector 220. Detection of one or more ions by the detector 220 may be used to generate a spectrum.

[00097] FIG. 3 illustrates a schematic of some functional components of an example ion source 100 and a detector 220.

[00098] The illustrated components 130, 140, 150, 220, are operationally coupled. Any number of intervening components can exist between them (including no intervening components).

[00099] The controller 150 (i.e., control circuitry) may comprise a processor 152 and memory 154. The processor 152 may be configured to read from and write to the memory 154. The processor 152 may also comprise an output interface via which data and / or commands are output by the processor 152 and an input interface via which data and / or commands are input to the processor 152. [000100] The memory 154 may be a non-transitory computer-readable storage medium. The memory 154 may store a computer program comprising computer program instructions (computer program code) that controls the operation of the ion source 100 when loaded into the processor 152. The computer program instructions, of the computer program, may provide the logic and routines that enables the ion source 100 to perform the method illustrated in FIG. 6. The processor 152, by reading the memory 154, can load and execute the computer program. [000101] The memory 154 may store data. The data may include, for example, path information. Although the memory 154 is illustrated as a single component / circuitry it may be implemented as one or more separate components / circuitry some or all of which may be integrated / removable and / or may provide permanent / semi-permanent / dynamic / cached storage. [000102] Although the processor 152 is illustrated as a single component / circuitry it may be implemented as one or more separate components / circuitry some or all of which may be integrated / removable. The processor 152 may be a single core or multi-core processor. [000103] As shown by the arrow from the processor 152 to the light source 130 in FIG. 3, the controller 150 may be configured to transmit data to and / or receive data from the light source 130. For example, the controller 150 may be configured to cause the light source 130 to emit light (e.g., to a region of the sample plate 120). In some examples, the controller may be configured to receive status information of the light source 130 from the light source 130. [000104] As shown by the arrow from the processor 152 to the actuator 140, the controller 150 may be configured to transmit data to and / or receive data from the actuator 140. For example, the controller 150 may be configured to cause the actuator 140 to move the support 110 and / or the light source 130 (i.e., such that the light source is configured to emit light to a (second) region of the sample plate 120). In some examples, the controller may be configured to receive status information of the actuator 140 from the light source 140. [000105] As shown by the arrow from the processor 152 to the detector 220, the controller 150 may be configured to receive data from the detector 220. For example, the controller 150 may be configured to receive an ion detection signal from the detector 220. [000106] In some examples, a computer program (e.g., instructions stored in the memory 154) may be configured to be executed by the controller 150. The computer program may be configured to cause the controller 150 to cause: the light source 130 to emit light to a first region 501 of the sample plate 120; the actuator 140 to move the support 110 relative to the light source 130 such that the light source 130 is configured to emit light to a second region 502 of the sample plate 120, the second region 502 overlapping the first region 501; and the light source 130 to emit light to the second region 502. [000107] In some examples, the mass spectrometer 10 may comprise the controller 150 (e.g., rather than the ion source 100). [000108] FIG. 4 shows an example sample plate 120. The sample plate 120 comprises a plurality of sample zones 400. A reference numeral has only been added to one of the twelve sample zones 400 shown in FIG. 4 for clarity purposes. [000109] The sample plate 120 may comprise any suitable number of sample zones 400. For example, a sample plate 120 may comprise ten or more sample zones 400. The sample plate 120 may comprise eighty or more sample zones 400. The sample plate 120 may comprise between eighty to two hundred and sixty sample zones 400. The sample plate 120 may comprise 84, 168, and / or 252 sample zones 400. [000110] Each sample zone 400 (of any of the plurality of sample zones 400 described above) may comprise at least thirty regions. Each sample zone 400 may be arranged to support a respective sample material. [000111] FIGs 5A to 5C show an example sample zone 400. For example, the sample zone 400 may be one or more of the sample zones 400 of the sample plate 120 shown in FIG. 4. [000112] Each of FIGs 5A to 5C show coordinate axis 500 comprising an x-axis and a y-axis. The x-axis may define a horizontal direction. The y-axis may define a vertical direction. [000113] FIG. 5A shows a sample zone 400 comprising a first region 501. The first region 501 is circular. The diameter of the first region 501 is denoted by reference sign D1. The diameter D1 may be 100pm. [000114] The arrow denoted by reference numeral 510 shows an example linear path (e.g., caused by the relative movement of the support 110 and the light source 130). [000115] The controller 150 may cause the light source 130 to emit light to the first region 501 of the sample plate 120. [000116] Subsequently, the controller 150 may cause the actuator 140 to move the support 110 relative to the light source 130 such that the light source 130 is configured to emit light to a second region 502 of the sample plate 120, the second region 502 overlapping the first region 501. An example of this is shown in FIG. 5B. [000117] FIG. 5B shows an example sample zone 400 comprising the features of the sample zone 400 shown in FIG. 5A. In addition to the features of the sample zone 400 shown in FIG. 5A, the sample zone 400 comprises a second region 502. [000118] The second region 502 is circular. The diameter of the second region 502 is denoted by reference sign D2. Diameter D2 of the second region 502 overlaps the diameter D1 of the first region 501. [000119] In some examples, the actuator 140 is configured to move the support 110 relative to the light source 130 such that the diameter D1 of the first region 501 and the diameter D2 of the second region 502 overlap by at least 1.5% of the diameter D1, D2 of the first and second regions 501, 502. For example, the actuator 140 may be configured to move the support 110 relative to the light source 130 such that the diameter D1 of the first region 501 and the diameter D2 of the second region 502 overlap by at least 2.75% of the diameter D1, D2 of the first and second regions 501, 502. [000120] In some examples, the actuator 140 is configured to move the support 110 relative to the light source 130 such that the diameter D1 of the first region 501 and the diameter D2 of the second region 502 overlap by less than or equal to 98.5%. [000121] FIG. 5B shows an overlap region 520 that defines the area in which the first region 501 and the second region 502 overlap. [000122] The controller 150 may be cause the light source 130 to emit light to the second region 502 of the sample plate 120. [000123] Subsequently, the controller 150 may cause the actuator 140 to move the support 110 relative to the light source 130 such that the light source 130 is configured to emit light to a third region 503 of the sample plate 120, the third region 503 overlapping the second region 502. An example of this is shown in FIG. 5C. [000124] FIG. 5C shows an example sample zone 400 comprising the features of the sample zone 400 shown in FIG. 5B. In addition to the features of the sample zone 400 shown in FIG. 5B, the sample zone 400 comprises a third region 503. [000125] The third region 503 is circular. The diameter of the third region 503 is denoted by reference sign D3. Diameter D2 of the second region 502 overlaps the diameter D3 of the third region 503. [000126] FIG. 5C shows an overlap region 530 that defines the area in which the second region 502 and the third region 503 overlap. [000127] Whilst the path 510 shown in FIGs 5A to 5C shows three regions 501, 502, 503, the skilled person should understand that the path 510 may comprise any suitable number of regions 501, 502, 503 (e.g., 30 regions 501, 502, 503). In some examples, the sample plate 120 may comprise a plurality of sample zones 400. Each sample zone 400 comprising any suitable number of regions 501, 502, 503. For examples, the sample plate 120 may comprise at least eighty sample zones 400, each of the eighty sample zones 400 comprising at least 30 regions (e.g., 35 or 64 regions). [000128] Figure 6 illustrates a schematic of a method 600 for providing ions from a sample material. For example, the method 600 may be performed at least in part by an ion source 100 as described above. [000129] At block 602, the method 600 comprises ionising, by a light source 130, the sample material at a first region 501. [000130] At block 604, the method 600 comprises moving the light source 130 relative to the sample region such that the light source 130 is configured to emit light 132 to a second region 502 overlapping the first region 501. [000131] At block 606, the method 600 comprises ionising, by the light source 130, the sample material at the second region 502. [000132] It should be understood that block 604 and block 606 may occur simultaneously or sequentially (e.g., block 604 may occur before block 606). [000133] It should be understood that block 604 and block 606 may be repeated such that light is emitted to the desired number of regions 501, 502, 503 of a (first) sample zone 400. Once this has occurred, the controller 150 may cause the light source 130 to move relative to the sample plate 120 such that the light source 130 is configured to emit light 132 to a first region 501 of a second sample zone 400. Block 604 and block 606 may be repeated such that light is emitted to the desired number of regions 501, 502, 503 of the second sample zone 400. [000134] Moving the light source relative to the sample region may comprise moving the light source relative to the sample region such that a diameter of the first region and a diameter of the second region overlap by at least 1.5% of the diameter of the first and second regions. [000135] Moving the light source relative to the sample region may comprise moving the light source relative to the sample region such that the diameter of the first region and the diameter of the second region overlap by less than or equal to 98.5%. [000136] The second region may only partially overlap the first region. [000137] The method 600 may comprise causing the actuator to move the support relative to the light source such that the light source is configured to emit light to N regions of a sample zone of the sample plate, wherein N is a natural number greater than or equal to 2. [000138] Moving the light source relative to the sample region may comprise continuously moving the light source relative to the sample region. [000139] Moving the light source relative to the sample region may comprises continuously moving the support. [000140] Moving the light source relative to the sample region may comprise moving the support relative to the sample region at a speed of less than 5 x 10'3 m s’1. [000141] Ionising may comprise the light source emitting one or more pulses of light at the sample region. The light source may emit one or more pulses of light at a frequency of greater than 450Hz. [000142] Although a few example embodiments have been shown and described, it will be appreciated by those skilled in the art that various changes and modifications might be made without departing from the scope of the invention, as defined in the appended claims. [000143] All the features disclosed in this specification, including any accompanying claims, abstract and drawings, may be combined in any combination, except combinations where at least some of such features and / or steps are mutually exclusive. [000144] Each feature disclosed in this specification, including any accompanying claims, abstract and drawings, may be replaced by alternative features serving the same, equivalent, or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features. [000145] The invention is not restricted to the details of the foregoing embodiments. The invention extends to any novel one, or any novel combination, of the features disclosed in this specification, including any accompanying claims, abstract and drawings, or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

Claims

1. An ion source for a mass spectrometer for providing ions from a sample material on a sample plate, the ion source comprising:a support arranged to support the sample plate;a light source configured to emit light to a region of the sample plate for ionising the sample material;an actuator configured to move the support relative to the light source; anda controller configured to cause:the light source to emit light to a first region of the sample plate;the actuator to move the support relative to the light source such that the light source is configured to emit light to a second region of the sample plate, the second region overlapping the first region; andthe light source to emit light to the second region.

2. The ion source of claim 1, wherein the actuator is configured to move the support relative to the light source such that a diameter of the first region and a diameter of the second region overlap by at least 1.5% of the diameter of the first and second regions.

3. The ion source according to any preceding claim, wherein the actuator is configured to move the support relative to the light source such that the diameter of the first region and the diameter of the second region overlap by less than or equal to 98.5%.

4. The ion source according to any preceding claim, wherein the second region only partially overlaps the first region.

5. The ion source according to any preceding claim, wherein the controller is configured to cause the actuator to move the support relative to the light source such that the light source is configured to emit light to N regions of a sample zone of the sample plate, wherein N is a natural number greater than or equal to 2.

6. The ion source according to any preceding claim, wherein the actuator is configured to continuously move the support relative to the light source.

7. The ion source according to any preceding claim, wherein the actuator is configured to move the support.

8. The ion source according to any preceding claim, wherein the actuator is configured to move the support relative to the light source at a speed of less than 5 x 10'3 m s-1.

9. The ion source according to any preceding claim, wherein the light source is configured to emit one or more pulses of light.

10. The ion source according to claim 9, wherein the light source is configured to emit one or more pulses of light at a frequency of greater than 450Hz.

11. The ion source according to any preceding claim, wherein the light source comprises a laser.

12. The ion source according to any preceding claim, wherein the region is a circular region.

13. The ion source according to claim 12, wherein the region comprises a diameter of 100pm.

14. A mass spectrometer comprising the ion source according to any preceding claim.

15. A computer program configured to be executed by the controller according to any preceding claim, the computer program configured to cause the controller to cause:the light source to emit light to a first region of the sample plate;the actuator to move the support relative to the light source such that the light source is configured to emit light to a second region of the sample plate, the second region overlapping the first region; andthe light source to emit light to the second region.

16. A method for providing ions from a sample material, the method comprising: ionising, by a light source, the sample material at a first region;moving the light source relative to the sample region such that the light source is configured to emit light to a second region overlapping the first region; andionising, by the light source, the sample material at the second region.

17. The method of claim 16, wherein moving the light source relative to the sample region comprises moving the light source relative to the sample region such that a diameter of the first region and a diameter of the second region overlap by at least 1.5% of the diameter of the first and second regions.

18. The method of claim 16 or 17, wherein moving the light source relative to the sample region comprises moving the light source relative to the sample region such that the diameter of the first region and the diameter of the second region overlap by less than or equal to 98.5%.

19. The method of claim 16, 17, or 18, wherein the second region only partially overlaps the first region.

20. The method of any of claims 16 to 19, comprising causing the actuator to move the support relative to the light source such that the light source is configured to emit light to N regions of a sample zone of the sample plate, wherein N is a natural number greater than or equal to 2.

21. The method of any of claims 16 to 20, wherein moving the light source relative to the sample region comprises continuously moving the light source relative to the sample region.

22. The method of any of claims 16 to 21, wherein moving the light source relative to the sample region comprises continuously moving the support.

23. The method of any of claims 16 to 22, wherein moving the light source relative to the sample region comprises moving the support relative to the sample region at a speed of less than 5 x 10'3 m s'1.

24. The method of any of claims 16 to 22, wherein ionising comprises the light source emitting one or more pulses of light at the sample region.

25. The method of claim 24, wherein the light source emits one or more pulses of light at a frequency of greater than 450Hz.

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