A collimator for particle detectors

Abstract

The present invention relates to a collimator for use on a particle sensor device, said the collimator is configured as a two-dimensional array comprising a plurality of particle channels arranged to select particles from an input face to an output face of said collimator, said output face of said collimator being arranged to be disposed onto an active area of said particle sensor device, and wherein said collimator further comprises vacuum means comprising a vacuum port in communication with each of said vacuum channels and arranged for connecting a vacuum pump to generate a vacuum in said particle channels of said collimator during use of said particle sensor device.

Description

[0001] Title: a collimator for particle detectors.

[0002] Description:

[0003] BACKGROUND

[0004] The present invention relates to a collimator.

[0005] Collimators come is several forms and types, and may for example be used to guide light. Typically, collimators may consist of a plurality of parallel guides or channels that direct and guide light or that may select other types of radiation into a desired surface and therefore function as a filter. Collimators may be considered filters as they may filter a stream of rays so that only those rays that are traveling parallel to the specified and longitudinal direction of the collimator are allowed to pass through.

[0006] Collimators may be used for x-ray, gamma-ray, neutron and alpha particle imaging, detection or counters as particularly some of such types of radiation are difficult to focus into a lens or a sensor. Collimators are also typically used in radiation detectors in which directional sensitivity is relevant.

[0007] The use of a collimator for any of the above mentioned sensor systems has many advantages, amongst which improved sensitivity as the collimator enhances the sensors sensitivity by directing the light or radiation into parallel beams. This focused beam increases the signal to noise ratio, allowing the sensor to detect small and low-intensity signals with greater accuracy.

[0008] Another important aspect of a collimator is that is allows increase of detector area. The collimator may guide and converge the light or radiation of a larger surface onto a smaller surface such that the active area of the sensor is increased by the larger area at the input side of the collimator. In such a way the collimator increases the resolution or accuracy as a larger number or radiating particles may be captured by the sensor.

[0009] Increase of surface area by the collimator however also introduces drawbacks as it increases the distance in between the object that is to be sensed, e.g. a sample of which the radiation is measured, and the sensor itself. In particular for certain applications and radiation types, this increase in distance, decreases the sensitivity of the sensor device.

[0010] It is therefore an object of the present invention, to provide a collimator for a particle detector which on the one hand increases the accuracy of the sensor, e.g. by having an improved signal-to-noise ratio, but on the other hand has no or little decrease in sensitivity due to the effect of the increase of distance between the sensor and the sample under test.

[0011] SUMMARY OF THE INVENTION

[0012] In a first aspect, there is provided, a collimator for use on a particle sensor device, said the collimator is configured as a two-dimensional array comprising a plurality of particle channels arranged to select particles from an input face to an output face of said collimator, said output face of said collimator being arranged to be disposed onto an active area of said particle sensor device, and wherein said collimator further comprises vacuum means comprising a vacuum port in communication with each of said vacuum channels and arranged for connecting a vacuum pump to generate a vacuum in said particle channels of said collimator during use of said particle sensor device.

[0013] Collimators may serve several purposes, amongst which to enhance sensor devices such as alpha particle sensors or spectrometers in general. With a collimator, the light or other type of radiation, depending on the type of application and the sensor device in which the collimator is used, is selected by the collimator channels onto the sensor or spectrometer. The collimators may be structured according to different types of configurations. In any type of configuration, the collimator comprises a plurality of channels, also referred to as particle channels as these guide or select the particles, e.g. alpha particles, beta particles, gamma particles, light or any other type of radiation, onto an active area of a sensor device. As such, the collimator is formed by a bundle of these particle channels which bundle has an input face and an output face. The input face is the face or side at which the collimator receives the particles, e.g. which are radiated from a sample. The output face is the face or side at which the collimator outputs the particles onto the sensor and more in particular, the active area of the sensor.

[0014] Typically, the sensor consists of a pixelized sensor having a pixelized active area with a certain resolution, for example 32x32, 64x64, 128x128, 256x256, 512x512, 1024x1024, etc. It is emphasized, that the collimator according to the present disclosure is not limited to any particular resolution of the sensor on which it is used. The collimator may have a similar amount of particle channels which correspond in number to the pixels of the sensor. The collimator may however also have a smaller number of channels, e.g. in a configuration in which each channel serves multiple pixels, or in a configuration in which several channels serve one single pixel. As such, the particle channels to pixel ratio may in an example have any ratio from 100:1 till 1 :1 till 1 : 100. In another example, the channel to pixel ratio lies between 10:1-1 :1 , or between 1 :1-1 :10 or is approximately 1 :1.

[0015] The channels may be oriented in a parallel manner in which the collimator input face and output face have equal or at least substantially equal surface area’s.

[0016] More preferably however, the input face of the collimator has a large surface area than the output face. This way, the active area and thereby the range of the sensors active area is enlarged. In such a configuration, the sensor is able to selectively detect a larger volume of particles. In such a configuration, the channels may be oriented in a converging manner, and / or may have a tapered configuration, narrowing from the input face towards the output face of said collimator. The use of the collimator is beneficial in a particle sensor device or a spectrometer, for known reasons and reasons mentioned above. The collimator however also introduces challenges.

[0017] Especially for certain applications, such as alpha particle detectors, sensors or spectrometers, the use of the collimator results in a larger distance between the sample (holder) and the sensor / detector / spectrometer, as the sample (holder) cannot be placed directly adjacent the sensor. The collimator therefor not only introduces a larger distance between the sensor and sample, but the effect thereof is, that the air present between sensor and sample, influences the measurement in a negative sense

[0018] The presence of air between the sample and the sensor has negative effects on accuracy and sensitivity. For example when used with an alpha particle sensor, the alpha particles, when traveling through air, can scatter or interact with air molecules, resulting in deviations from a straight trajectory. This scattering phenomenon can cause the alpha particles to spread out and disperse, making their detection less precise. Moreover, air molecules can slow down the alpha particles, reducing their overall energy and, consequently, their detectability or make the detected energy useless for spectrometry. These factors can decrease the accuracy and sensitivity of the system when there is an air gap between the source and the sensor. Also for other charged particles similar effect may occur.

[0019] To reduce the effect of the air, and therefor reduce the effect of placing the sample (holder) further away from the sensor, the collimator according to the present disclosure, is characterized by comprising vacuum means. The vacuum means as least comprise a vacuum port which may be located in a wall section of the housing of the collimator. The vacuum port allows the connecting a vacuum pump or a hose or other duct means to connect to a pump to generate a vacuum or at least lower atmospheric pressure by removing all or most of the air inside the collimator, and more particularly, inside the particle channels of the collimator. To this end, the vacuum port is connected with the particle channels in such a way that an air channel or duct is provided between port and the channels. Connecting a pump to the port, thus allows removing all or most of the air in the channels. Having a vacuum in the particle channels will resolve at least most of the issues related to the use of the collimator. Therefore a collimator is achieved which improves the signal-to-noise ratio of the sensor, but has no or little effect on decreasing sensitivity due to the effect of the increase of distance between the sensor and the sample under test.

[0020] In an example, the surface area of said collimator input face is larger than a surface area of said collimator output face.

[0021] In an example, the channels have a tapered configuration, narrowing from said input face towards said output face of said collimator.

[0022] In an example, the collimator has a number of channels corresponding to a number of pixels of a particle sensor on which said collimator is used, and wherein each of said plurality of channels is aligned with a single pixel of said particle sensor.

[0023] In an example, the vacuum port comprises an appendage for controlling air in and out of said collimator.

[0024] When the vacuum port comprises an appendage it provides control of the airflow within the air vacuum means, ensuring smooth and uniform control of the vacuum in the collimator channels. The appendage may be provided with an additional barrier or filter to prevent debris or contaminants from entering the collimator, maintaining a clean environment. Such barrier or filter may in addition or alternatively also be provided on the input face of the collimator, e.g. to prevent debris and contamination. Furthermore, the appendage may be an adjustable appendage which allows for adaptability in the vacuum in the collimator.

[0025] In an example, the vacuum means comprise a valve.

[0026] With a valve, the vacuum means may have valve to maintain the vacuum inside the collimator, and in particular its channels. In an example, the valve is a one-way valve configured to maintain said vacuum in said channels.

[0027] In an example, the vacuum means comprise a plurality of vacuum channels connecting the vacuum port with each of the particle channels of the collimator.

[0028] In an example, the vacuum channels are disposed transversely onto said channels of said collimator.

[0029] In a practical embodiment, the collimator is comprised of vacuum means which are present in the collimator as vacuum or air channels or ducts. These ducts constitute a network of air channels that connect each particle channel with the vacuum port and thus the vacuum pump connected to the port.

[0030] In an example, the collimator is comprised of a material having low outgassing properties to minimize contamination and maintain the vacuum within the particle channels.

[0031] Outgassing refers to the release of volatile substances, such as gases or vapors, from the material of which the collimator is manufactured. In the context of the collimator according to the present disclosure, outgassing can be problematic because it can introduce contaminants into the particle channels, compromising the purity of the vacuum environment and distorting and contaminating the measurement. These contaminants can interfere with the collimation process which potentially and ultimately, may degrade the performance of the sensor. By utilizing a material with low outgassing properties, the collimator mitigates the risk of contamination. Such materials have reduced levels of volatile substances that could be released into the vacuum. This minimizes the presence of contaminants within the particle channels and helps maintain the desired vacuum conditions necessary for accurate particle detection. The use of a low outgassing material in the collimator ensures a cleaner and more stable vacuum environment, preserving the integrity of the particle channels and optimizing the collimation process. It improves the reliability and longevity of the collimator by reducing the potential for contamination-related issues that could adversely impact the sensor's accuracy and sensitivity.

[0032] Examples of such material are Polyether Ether Ketone (PEEK), Polytetrafluoroethylene (PTFE), Polyimide (PI), Polyethylene Terephthalate (PET), and Polypropylene (PP).

[0033] In an example, the collimator is comprised of thermoplastic material.

[0034] Such material may be any one or more of Polyether Ether Ketone (PEEK), Polytetrafluoroethylene (PTFE), Polyimide (PI), Polyethylene Terephthalate (PET), and Polypropylene (PP).

[0035] PEEK is a high-performance thermoplastic known for its excellent mechanical and chemical resistance properties. It exhibits low outgassing characteristics, making it suitable for applications requiring a clean and low- contamination environment, such as aerospace and semiconductor industries.

[0036] PTFE, commonly known as Teflon, is a widely used thermoplastic known for its nonstick and chemical inertness properties. It also has low outgassing characteristics, making it suitable for applications where minimal contamination is critical, such as in high-vacuum systems or sensitive electronic devices.

[0037] Polyimide is a high-temperature thermoplastic known for its excellent thermal stability, mechanical strength, and chemical resistance. It exhibits low outgassing properties, making it suitable for use in vacuum environments, such as in space applications and semiconductor manufacturing.

[0038] PET is a commonly used thermoplastic known for its good mechanical properties and transparency. It also has low outgassing characteristics, making it suitable for applications that require a clean environment, such as in optical systems or electronic devices. Polypropylene is a versatile thermoplastic known for its chemical resistance, toughness, and low cost. It exhibits relatively low outgassing properties, making it suitable for various applications, including those requiring a clean environment like laboratory equipment or medical devices.

[0039] In an example, the thermoplastic material is selected in accordance with particles to be detected by said particle sensor device, and in particular, wherein said selection is based on an enhanced particle reflection.

[0040] Such material may be any one or more of Polyether Ether Ketone (PEEK), Polytetrafluoroethylene (PTFE), Polyimide (PI), Polyethylene Terephthalate (PET), and Polypropylene (PP), selected for a particular use of the particles that are to be measured.

[0041] In an example, the collimator is manufactured by three-dimensional additive printing.

[0042] The collimator according to the present disclosure can be manufactured using 3D printing techniques, which offer several advantages in terms of design flexibility and customization. With 3D printing, the collimator can be produced as a single, integrated piece, eliminating the need for assembly of multiple components. This results in a simplified manufacturing process and potentially reduced costs. Moreover, such manufacturing may ensure an air tight design such that the particle channels maintain their vacuum even under use and under extreme levels of vacuum or low atmospheric pressure.

[0043] In 3D printing, there are various techniques available that can be suitable for manufacturing such a collimator for a particle sensor.

[0044] Stereolithography may be used as a 3D printing technique that uses a UV laser to selectively cure a liquid resin, layer by layer, to build the desired object. It offers high resolution and smooth surface finishes, which are advantageous for fabricating collimator channels with precise dimensions and smooth inner surfaces. SLA can achieve intricate geometries, allowing for customized designs tailored to specific particle sensing requirements.

[0045] Alternatively, selective laser sintering may be used which utilizes a high- power laser to selectively fuse powdered thermoplastic materials. This process allows for the creation of complex structures with good mechanical properties. This process is suitable for manufacturing collimators with larger dimensions or for applications that require more robust and durable collimator designs.

[0046] Both techniques enable the production of collimators from a wide range of materials, as listed above, but not excluded to, and also including thermoplastics such as nylon, polycarbonate, or acrylonitrile butadiene styrene (ABS). These materials can offer sufficient optical properties, durability, and resistance to environmental conditions.

[0047] Alternatively, other 3D printing techniques may be used, amongst which and not excluded to, fused deposition modeling which is one of the most widely used 3D printing techniques. It involves extruding a thermoplastic filament through a heated nozzle, which deposits layers of material onto a build platform. The layers cool and solidify, gradually building up the object. This process is suitable for producing collimators using thermoplastics such as ABS, PLA, or PETG. It offers a relatively low- cost option with good material availability. Selective laser melting may also be used as an additive manufacturing technique that uses a high-power laser to selectively melt and fuse metal or thermoplastic powder particles. In the case of thermoplastics, the laser selectively melts the powdered material layer by layer to form the desired object. It is suitable for producing high-quality, complex collimators from materials like nylon, PEEK, or PEI. It is often utilized for more demanding applications where high strength, heat resistance, or chemical resistance is required. Alternatively, digital light processing may be used, which is a 3D printing technique that utilizes a digital projector to cure liquid photopolymer resin layer by layer. A light source projects UV light onto the resin, solidifying it according to the pattern of each layer. It offers high- resolution printing capabilities and is suitable for producing collimators with intricate designs and fine details. It is commonly used with materials such as epoxy-based resins or polyurethanes. Finally, continuous liquid interface production may be used which is an innovative 3D printing process that utilizes a combination of light and oxygen to selectively cure a liquid resin. It employs a transparent window that allows light to pass through, solidifying the resin. It enables the production of parts with excellent surface finishes and mechanical properties. It is suitable for manufacturing high-performance collimators using resins optimized for optical clarity and durability.

[0048] In a second aspect, there is provided, a particle sensor system comprising a particle sensor device and comprising a collimator according to any of the previous claims.

[0049] In an example, the particle sensor system further comprises a vacuum pump, in communication with said vacuum port of said vacuum means, for generating said vacuum in said particle channels of said collimator during use of said particle sensor device.

[0050] In an example, the particle sensor system further comprises a sample holder, arranged to holding a sample to be tested with said particle sensor device of said particle sensor system, and wherein said sample holder has a shape mating said input face of said collimator.

[0051] In an example, the mating sample holder and / or said input face of said collimator comprises a deformable sealing for providing, during use of said particle sensor device, an air-tight seal between said sample holder and said collimator.

[0052] In an example, the particle sensor device of said particle sensor system comprises an alpha particle sensor device.

[0053] In another aspect, a collimator is provided, configured as a two- dimensional array comprising a plurality of particle channels arranged to select particles from an input face to an output face of the collimator, allowing particles radiating from a radioactive sample under test to pass through the collimator towards a particle sensor such as the pixelated particle sensor or detector of the first aspect, or towards any other sensor or detector means, the collimator being positioned in front of the particle sensor and being configured as an alpha particle air-flush collimator, wherein the air-flush collimator is arranged to restrict the passage of the radiation particles and select particles, such as particles on a path towards pixels of the particle sensor.

[0054] In an example, the air-flush collimator further comprises air-flush system means, such as an air pump, comprising an above ambient pressure compartment that is in fluid communication with air channels to flush said above ambient pressure compartment and said air channels, arranged to generate during use the above ambient pressure in the particle channels of the collimator.

[0055] These and other aspects of the present disclosure will be elucidated further with reference to the attached figures. In these figures:

[0056] BRIEF DESCRIPTION OF THE FIGURES

[0057] Figure 1 schematically shows an embodiment of a particle detector according to an aspect of the present disclosure;

[0058] Figures 2a-2d show details of the collimator according to an aspect of the present disclosure.

[0059] DETAILED DESCRIPTION OF THE FIGURES

[0060] Figure 1 schematically shows an embodiment of a collimator 17 used in a particle sensor device 1 , the collimator 17 is configured as a two-dimensional array comprising a plurality of particle channels arranged to select particles from an input face to an output face of the collimator, and is arranged to comprise vacuum means with a vacuum port which is in communication with each of the vacuum channels in the collimator, and thereby arranged for connecting a vacuum pump to generate a vacuum in the particle channels of the collimator during use of the particle sensor device 1. In an embodiment, the particle sensor device 1 is an alpha spectrometry detector 1 , according to an aspect of the present disclosure. The alpha spectrometry detector 1 is arranged for measuring one or more characteristics of radiation particles 3 received from a radioactive sample 5 under test. The radioactive sample 5 is comprised in a radiopharmaceutical, for example used in alpha radionuclide therapy for treating cancer that has metastasised in the body.

[0061] The alpha spectrometry detector 1 comprises detector means 7, a readout circuit 11 , a spectroscopic analyser means 13 and a collimator 17.

[0062] The detector means 7 comprise a pixelated detector 9 comprising a two dimensional array of detector pixels 9X,Y sensitive to the radiation particles 3 received from the radioactive sample 5, wherein the radiation particles 3 can comprise alpha particles, beta particles and / or gamma particles. The detector means 7 are arranged to record the incoming radiation particles 3 and its energy deposition, temporal data or arrival time, and the spatial data or the index number of the respective pixels 9X.Y, and retrieve this data simultaneously on an event basis, to generate a charge pattern 21 X,Y.

[0063] The detector means 7 are implemented as an Application Specific Integrated Circuit, ASIC, comprising a 256x256 pixilated event mode detector chip with a pixel size of 55 pm, for example a timepix3 sensor, and are calibrated prior to use, for example by correcting for pixel-to-pixel variations and / or temporal data or timing of the recording.

[0064] The readout circuit 11 is in electric communication with the detector means 7, integrated into the detector chip which turns every individual 55 pm pixel in single event readout detector with few ns timeline. The readout circuit 11 is arranged to continuous readout each pixel 9x,Y Of the array. The readout circuit 11 is arranged to generate, based on the readout of each of the detector pixels 9X.Y, a charge pattern 21 X,Y for each hit of a radiation particle 3 on the detector means 7. The charge pattern 21 X,Y comprises spatial data, temporal data, energy deposited, pixel coordinates, time of arrival and / or time over threshold data for each detector pixel 9X,Y of the array. Continuous readout of each pixel 9X,Y enables real time analysis of the radiation particles 3. The readout circuit 11 is furthermore arranged for filtering the energy deposited in the charge pattern 21 X,Y, wherein the filtering comprises pixel grouping to generate charge peaks in the pattern 21 X,Y with high contrast.

[0065] The spectroscopic analyser means 13 are in electric communication with the readout circuit 11 and are arranged to receive each charge pattern 21 X,Y generated by the readout circuit 11. The spectroscopic analyser means 13 are further arranged for matching the charge pattern with a database of charge patterns to identify corresponding alpha particles, beta particles and / or gamma particles of the sample 5, for generating an alpha, beta and / or gamma spectrum of the sample 5.

[0066] The spectroscopic analyser means 13 comprises a programmable logic device 15, wherein the programmable logic device 15 is a Field Programmable Gate Array, FPGA. The FPGA is arranged for matching the charge pattern 21 X,Y with a database of charge patterns to identify corresponding alpha particles, beta particles and / or gamma particles of the radioactive sample 5 under test. The matching process involves implementation of one or various algorithms or techniques that assess the similarity between the received charge pattern 21 X,Y and the patterns in the database, for example by statistical analysis, pattern recognition algorithms, or machine learning methods to find the best match.

[0067] The FPGA is configured for one or more functions of noise filtering, signal amplification, baseline correction, data formatting, data transformation, event identification, particle tracking, and wherein one or more of these functions are implemented into the FPGA as one or more logic circuits. Furthermore, the FPGA is configured for performing pattern recognition to determine one or more characteristics of each charge pattern 21 X,Y as a particle event, by identing each particle's spatial data, temporal data and energy deposited and wherein the pattern recognition function is implemented into the FPGA as one or more logic circuits.

[0068] The collimator 17, for example a 3D printed collimator, is arranged for directing the radiation particles 3 from the radioactive sample 5 under test, towards the detector means 7. The collimator 17 is positioned in front of the detector means 7, and is comprised of an alpha particle vacuum collimator arranged to restrict the passage of the radiation particles 3 and direct the radiation particles 3 towards the pixels 9X,Y of the array of the pixelated detector 9.

[0069] The collimator comprises a plurality wave guides, having one guide per pixel 9x,y of the array of the pixelated detector 9 and can furthermore comprise one or more of lenses, filters and gratings to enhance guiding the radiation particles 3 onto the pixels 9X,Y of the array of the pixelated detector 9.

[0070] In Fig. 2a-d more details of an embodiment of the collimator according to an aspect of the present invention is shown.

[0071] The collimator 17 has a tapered configuration, which means, that the input face 19 is larger than the output face 20, resulting in particle channels 17-3a, 17-3b, 17-3n, are tapered towards the output face 20.

[0072] The channels 17-3 are substantially parallel to each other and select the particles from the object under test, i.e. the sample, which can be placed at the input face, for example by use of a sample holder, towards the output face 20, which is to be placed on the chip / sensor / spectrometer, etc. depending on the type of application in which the collimator is used.

[0073] Each particle channel 17-3a-n, is in connection with, meaning that air is allowed to pass between, the vacuum port 17-4a. The port 17-4a is connected with several vacuum channels 17-4b which interconnect the particle channels 17-3a-n.

[0074] The vacuum means, comprising the vacuum channels 17-4b and the vacuum port 17-4a, allow to provide a vacuum or at least low pressure with little air in the particle channels, such that the effect of the air on the measurement is minimized or removed completely. Although the figures disclose a specific type of collimator, the skilled person will appreciate that this is merely an embodiment and that different configurations may be applicable as well, and fall within the scope of the pending claims. For example a collimator with a different housing 17-2, with or without a raster or mesh at the input face and / or output face, or having a tapered design towards the output face in stead of the input face as shown in the figures. Also a design having parallel channels falls within the scope of the pending claims.

Claims

CLAIMS1. A collimator for use on a particle sensor device, said the collimator is configured as a two-dimensional array comprising a plurality of particle channels arranged to select particles from an input face to an output face of said collimator, said output face of said collimator being arranged to be disposed onto an active area of said particle sensor device, and wherein said collimator further comprises vacuum means comprising a vacuum port in communication with each of said vacuum channels and arranged for connecting a vacuum pump to generate a vacuum in said particle channels of said collimator during use of said particle sensor device.

2. The collimator for use on a particle sensor device according to claim 1 , wherein a surface area of said collimator input face is larger than a surface area of said collimator output face.

3. The collimator for use on a particle sensor device according to claim 2, wherein said channels have a tapered configuration, narrowing from said input face towards said output face of said collimator.

4. The collimator for use on a particle sensor device according to any of the previous claims, wherein said collimator has a number of channels corresponding to a number of pixels of a particle sensor on which said collimator is used, and wherein each of said plurality of channels is aligned with a single pixel of said particle sensor.

5. The collimator for use on a particle sensor device according to any of the previous claims, wherein said vacuum port comprises an appendage for controlling air in and out of said collimator.

6. The collimator for use on a particle sensor device according to any of the previous claims, wherein vacuum means comprise a valve.

7. The collimator for use on a particle sensor device according to claim 6, wherein said valve is a one-way valve configured to maintain said vacuum in said channels.

8. The collimator for use on a particle sensor device according to any of the previous claims, wherein said vacuum means comprise a plurality of vacuum channels connecting the vacuum port with each of the particle channels of the collimator.

9. The collimator for use on a particle sensor device according to claim 8, wherein said vacuum channels are disposed transversely onto said channels of said collimator.

10. The collimator for use in a particle sensor device according to any of the previous claims, wherein said collimator is comprised of a material having low outgassing properties to minimize contamination and maintain the vacuum within the particle channels.

11. The collimator for use in a particle sensor device according to any of the previous claims, wherein said collimator is comprised of thermoplastic material.

12. The collimator for use on a particle sensor device according to claim 11 , wherein said thermoplastic material is selected in accordance with particles to be detected by said particle sensor device, and in particular, wherein said selection is based on an enhanced particle reflection.

13. The collimator for use on a particle sensor device according to claim 11 or 12, wherein said collimator is manufactured by three-dimensional additive printing.

14. A particle sensor system comprising a particle sensor device and comprising a collimator according to any of the previous claims.

15. The particle sensor system according to claim 14, wherein said particle sensor system further comprises a vacuum pump, in communication with said vacuum port of said vacuum means, for generating said vacuum in said particle channels of said collimator during use of said particle sensor device.

16. The particle sensor system according to claim 14 or 15, wherein said particle sensor system further comprises a sample holder, arranged to holding a sample to be tested with said particle sensor device of said particle sensor system, and wherein said sample holder has a shape mating said input face of said collimator.

17. The particle sensor system according to claim 16, wherein said mating sample holder and / or said input face of said collimator comprises a deformable sealing for providing, during use of said particle sensor device, an air-tight seal between said sample holder and said collimator.

18. The particle sensor system according to any of the previous claims 14-17, wherein said particle sensor device of said particle sensor system comprises an alpha particle sensor device.

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