Panel Radiation Detector

Abstract

A panel radiation detector (10") for detecting radiation events of ionizing radiation, comprising a plurality of adjacent plastic scintillator slabs (i")z, a plurality of silicon photomultiplier tube sensors (21") arranged at the edge (12") of at least one of the plastic scintillator slabs (1") and configured to detect scintillation light generated in the scintillator slab (1") in response to a radiation event, and a plurality of signal processing units, each of which is connected to one of the silicon photomultiplier tube sensors (21"), wherein each of the signal processing units comprises a digitization circuit configured to generate a digitized signal for signal analysis by performing 1-bit digitization on a detection signal generated by at least one of the silicon photomultiplier tube sensors (21") in response to the detected scintillation light, so as to determine the energy of the detected radiation event.

Description

Technical Field

[0001] The present invention relates to a panel radiation detector for detecting radiation events of ionizing radiation and a method for processing detection signals of the panel radiation detector for detecting radiation events of ionizing radiation. Background Art

[0002] Radiation detectors comprising scintillators are widely used to detect ionizing radiation, especially for detecting nuclear and / or radioactive sources, in particular special nuclear materials (SNM). Detection is performed by measuring the scintillation light produced when radiation interacts with the scintillation material of the scintillator.

[0003] Conventionally, the readout of the scintillation light of a radiation detector is performed by using a photomultiplier tube (PMT).Recently, solid-state detectors such as silicon photomultiplier (SiPM) sensors have become a useful alternative to the light readout of scintillators.

[0004] Compared to PMTs, SiPM sensors offer the advantages of low power operation, small size, mechanical robustness, and insensitivity to magnetic fields. By using SiPM sensors, smaller radiation detectors can be obtained compared to PMTs, where the SiPM sensors can be attached to the scintillator in a flexible manner. In addition, the need for a light guide can be avoided.

[0005] The SiPM includes a dense array of single photon avalanche diode (SPAD) sensors operating in Geiger mode. In addition, the SiPM integrates multiple quenching resistors, each coupled to a SPAD sensor. The SPAD sensors with their quenching resistors form a microbattery, where a typical SiPM exhibits 100 ns per mm 2 Microcell densities range from one hundred to several thousand.

[0006] Regarding scintillators, plastic scintillators have proven to be an inexpensive solution for detecting various ionizing radiations. Commonly used plastic scintillator materials are polyvinyl toluene (PVT), PET, polystyrene or other organic materials. However, it is known that it is difficult to use plastic scintillators for spectroscopic measurements because their energy resolution is poor compared to, for example, crystal scintillators with high atomic numbers. Summary of the invention

[0007] When developing radiation detectors for detecting ionizing radiation, it is desirable to improve detection sensitivity and efficiency on the one hand and to improve cost-effectiveness on the other hand. Both can be achieved by improving the configuration of the sensor part of the radiation detector and / or the electronic part for signal processing.

[0008] Therefore, an object of the present invention is to provide a radiation detector comprising a plastic scintillator and to provide a method for processing a detection signal of a radiation detector, which at least partially improve the prior art and avoid at least some of the disadvantages of the prior art.

[0009] According to the invention, this object is achieved by the features of the independent claim. Furthermore, further advantageous embodiments emerge from the dependent claims and the description as well as the drawings.

[0010] According to one aspect of the present invention, the object is particularly achieved by a panel radiation detector for detecting radiation events of ionizing radiation, the panel radiation detector comprising a plurality of adjacent plastic scintillator slabs, a plurality of silicon photomultiplier tube sensors arranged at the edge of at least one of the plastic scintillator slabs and configured to detect scintillation light generated in the scintillator slab in response to the radiation event, and a plurality of signal processing units, each of which is connected to one of the silicon photomultiplier tube sensors, wherein each of the signal processing units comprises a digitization circuit configured to generate a digitized signal for signal analysis by performing 1-bit digitization on a detection signal generated by at least one of the silicon photomultiplier tube sensors in response to the detected scintillation light to determine the energy of the detected radiation event.

[0011] By providing a plurality of adjacent plastic scintillator slabs, a segmented radiation detector can be realized, wherein each scintillator slab can be independently read out by a silicon photomultiplier tube (SiPM) sensor arranged at at least one edge of at least one of the plastic scintillator slabs. Preferably, each scintillator slab features one or more edges where a plurality of SiPM sensors are arranged.

[0012] The term "edge" in relation to the scintillator slab is generally understood as a lateral edge of the scintillator slab. However, in some embodiments, the edge may alternatively or additionally be understood as a top surface and / or a bottom surface of the plastic scintillator slab.

[0013] Depending on the specific needs and the desired geometry of the radiation detector, the plastic scintillator slab or the panel radiation detector, respectively, can be arranged in a highly flexible manner. The arrangement of the plastic scintillator slab together with the small size of the SiPM sensor advantageously enables a significant reduction in the thickness of the panel radiation detector. Therefore, the panel radiation detector according to the present invention is also called a "flat gamma detector". The low cost of the SiPM sensor allows the arrangement of multiple SiPM sensors at the edge of the scintillator slab, which increases the sensitivity and spatial resolution of the radiation detection.

[0014] In particular, the aspect ratio d / l and / or d / w of the plastic scintillator slab is preferably below unity, where d is the thickness of the plastic scintillator slab, l is the length and w is the width. In an embodiment, the aspect ratio d / l and / or d / w is between 0.01 and 0.2.

[0015] Furthermore, the thickness of the plastic scintillator is preferably of the order of magnitude of one side of the active area of ​​one of the SiPM sensors. In an embodiment, the thickness of the plastic scintillator slab is one to five times, preferably one to two times, greater than one side of the active area of ​​one of the SiPM sensors.

[0016] The aspect ratio of the plastic scintillator slab and the thickness of the plastic scintillator slab comparable to one side of the active area of ​​the SiPM sensor advantageously result in a high light collection capability.

[0017] Independent readout of the SiPM sensors is achieved by a plurality of signal processing units each assigned to one of the SiPM sensors. Therein, cost-effective and simple signal processing electronics are advantageously provided by a digitization circuit configured to perform 1-bit digitization of an analog detection signal generated by at least one of the SiPM sensors when scintillation light generated in one of the scintillator slabs due to a radiation event is detected. The detection signal of the SiPM sensor may be processed by various intermediate processing steps before being digitized by the digitization circuit, as further described below, the intermediate processing steps including, for example, pre-amplification, amplification, pulse shaping, etc. In particular, the digitized signal is generated by 1-bit digitization for determining the energy of the detected radiation event. The use of a digitization circuit configured to perform 1-bit digitization provides the advantage of a simple and efficient analog-to-digital conversion technique for processing the detection signal of the SiPM sensor and for determining the energy of the detected radiation event.

[0018] In the context of the present invention, pulse shaping is understood as signal shaping, i.e. shaping of the signal by an electronic circuit system, and is distinguished from pulse shaping discrimination (PSD), which is a technique used in scintillators to discriminate signals of different types of radiation, as understood by those skilled in the art.

[0019] Preferably, the panel radiation detector comprises analysis circuitry connected to the digitising circuitry and configured to determine an energy of a detected radiation event using the digitised signals of one or more of the digitising circuitry.

[0020] The digitizing circuit allows generating a digitized signal with information about the time intervals during which the detection signal is above a predetermined threshold. Based on the digitized signal, the analyzing circuit can perform a pulse width analysis on the detection signal and determine the energy of the detected radiation event. Preferably, the analog detection signal is pulse shaped by the pulse shaping circuit before being digitized by the digitizing circuit.

[0021] Compared to obtaining energy information by integrating the detection signal (i.e., determining the area under the detection signal), a panel radiation detector including a digitization circuit configured to perform 1-bit digitization advantageously allows the energy of the radiation event to be determined based on the pulse width of the detection signal above a predetermined threshold as determined by the digitization circuit. Using the pulse width and a characteristic attenuation component due to the plastic scintillator material and / or components of the electronic circuit system of the panel radiation detector, the energy of the detected radiation event can be determined by the analysis circuit. Therefore, compared to obtaining energy information by integrating the detection signal, the panel radiation detector provides the advantage of simplified signal processing to obtain energy information.

[0022] In an embodiment, the sampling rate of the digitizing circuit is approximately 10 ns.

[0023] Determining the energy of a radiation event by integrating the detection signal typically requires approximately 8 to 10 bit digitizers with a sampling rate of approximately 1 to 100 ns per channel. Placing several SiPMs around the scintillator surface requires processing a large number of channels, making the common method of inferring charge integration from each SiPM using an 8-10 bit digitizer laborious for signal processing. Therefore, as described herein, determining the energy of a radiation event based on pulse width using 1-bit digitization provides simplification of signal processing and improves detection efficiency.

[0024] The increased light collection due to improved total internal reflection within the plastic scintillator slab due to its geometry and arrangement, combined with the processing scheme using pulse width analysis and 1-bit digitization as described herein, allows sufficient spectral resolution to be obtained to perform spectral analysis, which is not possible in the prior art using ordinary plastic scintillator detectors, especially ordinary plastic scintillator blocks.

[0025] Plastic scintillator materials may include polyvinyl toluene (PVT), PET, polystyrene, or other organic materials.

[0026] The space between the SiPM sensor and the plastic scintillator slab can be filled with optical grease to increase light coupling.

[0027] The panel radiation detector is particularly suitable for detecting gamma radiation. However, detection capabilities for other radiations such as alpha or beta radiation may alternatively or additionally be provided.

[0028] Those skilled in the art understand that plastic scintillator slabs may abut one another without being in direct contact with one another. For example, the interface between adjacent scintillator slabs may feature sufficient space for accommodating SiPM sensors, PCBs, optical grease, and the like.

[0029] In an embodiment, the thickness of the plastic scintillator slab is between one and five times the thickness of one side of the SiPM sensor area. Advantageously, this allows the scintillation light to be transmitted to the SiPM sensor by total internal reflection within the scintillator slab.

[0030] In an embodiment, at least two plastic scintillator slabs adjoin each other laterally.

[0031] In an embodiment, at least two plastic scintillator slabs are stacked vertically on top of each other.

[0032] By vertically stacking scintillator slabs, a multilayer panel radiation detector can be obtained, which advantageously retains the advantages of thin scintillators for optimized light collection. At the same time, due to the multilayer structure, the reduced efficiency of thin scintillators for high-energy radiation can be overcome. In the context of the present invention, the term "panel radiation detector" is understood to also include embodiments of multilayer panel radiation detectors, i.e. embodiments of panel radiation detectors comprising a multilayer structure of scintillator slabs.

[0033] In an embodiment, the panel radiation detector comprises at least one first plastic scintillator slab and at least one second plastic scintillator slab stacked vertically on top of each other, wherein the thickness of the at least one first plastic scintillator slab is less than the thickness of the at least one second plastic scintillator slab. Thus, a multi-layer, in particular two-layer panel radiation detector can be provided, which has a thinner front panel comprising the at least one first plastic scintillator slab operating as a low energy detection panel, and has a thicker rear panel comprising the at least one second plastic scintillator slab operating as a high energy detection panel.

[0034] The thickness of the at least one second plastic scintillator slab may be 4 to 20 times, preferably 6 to 15 times, particularly preferably 8 to 10 times, the thickness of the at least one first plastic scintillator slab.

[0035] Preferably, the thinner front panel and the thicker rear panel are arranged so that the thinner front panel is closer to the radiation source in question than the thicker rear panel. For example, this can be achieved by placing the thinner front panel next to the monitoring area of ​​the panel radiation detector and placing the thicker rear panel behind the thinner front panel relative to the monitoring area, wherein the radiation source in question is placed so that the panel radiation detector can scan it. For example, the thinner front panel is arranged next to the passage of the radiation detection hallway, and the thicker rear panel is arranged behind the thinner front panel relative to the passage of the radiation detection hallway.

[0036] The advantage provided by using two layers including first and second plastic scintillator slabs having different thicknesses is that the sensitivity of the panel radiation detector to both low-energy gamma radiation and high-energy gamma radiation can be improved. Therefore, the energy range in which the panel radiation detector can detect gamma radiation can be increased. In addition, at least one first plastic scintillator slab and at least one second plastic scintillator slab are preferably designed to present a thickness such that at least one first plastic scintillator slab is primarily sensitive to low-energy gamma radiation and insensitive to high-energy gamma radiation and at least one second plastic scintillator slab is primarily sensitive to high-energy gamma radiation and insensitive to low-energy gamma radiation. Therefore, by using vertically stacked plastic scintillator slabs having different thicknesses, a multilayer, in particular two layers, having a selective detection capability depending on the energy of gamma radiation can be provided.

[0037] The at least one first plastic scintillator slab is preferably configured to present a thickness optimized for detecting low energy gamma radiation. Typically, increasing the thickness of the plastic scintillator can have a negative impact on the detection of low energy gamma radiation due to a small amount of energy deposition from the low energy gamma radiation interaction. By reducing the thickness of the plastic scintillator slab, for the at least one first plastic scintillator slab, the light collection efficiency can be increased, so that even a small amount of energy deposition from the low energy gamma radiation interaction can be detected, while the efficiency of detecting high energy gamma radiation can still be low due to insufficient attenuation.

[0038] Preferably, the thickness of the at least one first plastic scintillator slab is of the order of magnitude of one side of the active area of ​​one of the silicon photomultiplier tube sensors arranged at the edge of the at least one first plastic scintillator slab. In an embodiment, the thickness of the at least one first plastic scintillator slab is 1-4 times, preferably 1-2 times, of one side of the active area of ​​one of the silicon photomultiplier tube sensors arranged at the edge of the at least one first plastic scintillator slab. In an embodiment, the thickness of the at least one first plastic scintillator slab is between 3-15 mm, preferably between 5-10 mm.

[0039] In an embodiment, the thinner front panel includes a plurality of laterally adjacent first plastic scintillator slabs and a plurality of silicon photomultiplier tube sensors, which are arranged at the edge of at least one of the first plastic scintillator slabs and are configured to detect scintillation light generated in the first plastic scintillator slab. Therefore, a segmented radiation detector for low-energy gamma radiation can be provided by a thinner front panel. Providing a thinner front panel with a plurality of laterally adjacent first plastic scintillator slabs provides an advantage that a signal-to-noise ratio can be improved. Since a greater number of silicon photomultiplier tube sensors are arranged between a plurality of laterally adjacent first plastic scintillator slabs, the path of scintillation light between generation and detection can be reduced, thereby enabling the light collection efficiency to be improved.

[0040] In an embodiment, the area of ​​the first plastic scintillator slabs of the plurality of transversely adjacent first plastic scintillator slabs is within 10'000 mm 2 and 14'000mm 2 Between, preferably 11'000mm 2 and 13'000mm 2 between 12'000 mm and 12'000 mm, particularly preferably about 12'000 mm 2 .

[0041] In an embodiment, the thinner front panel comprises between 5 and 15, preferably between 7 and 13, particularly preferably approximately 10 laterally adjacent first plastic scintillator slabs.

[0042] The at least one second plastic scintillator slab is preferably configured to present a thickness optimized for detecting high energy gamma radiation. In particular, the thickness is preferably optimized so that the attenuation is sufficient to enable detection of the high energy gamma radiation. The light collection efficiency of the at least one second plastic scintillator slab is typically about one order of magnitude lower than one of the at least one first plastic scintillator slabs. However, since the high energy gamma radiation deposits sufficient energy to produce a large amount of scintillation light, the at least one second plastic scintillator slab is sensitive enough to detect the high energy gamma radiation compared to the low energy gamma radiation, while the efficiency of detecting the low energy gamma radiation may still be low due to the attenuation in the at least one second plastic scintillator slab.

[0043] In an embodiment, the thicker rear panel comprises a single second plastic scintillator slab, wherein the plurality of silicon photomultiplier tube sensors are arranged at the edge of the second plastic scintillator slab. In an alternative embodiment, the thicker rear panel comprises two, three or four or more second plastic scintillator slabs. Preferably, the number of first plastic scintillator slabs is greater than the number of second plastic scintillator slabs.

[0044] In an embodiment, the thickness of the at least one second scintillator slab is between 20 and 60 mm, preferably between 30 and 50 mm, particularly preferably approximately 40 mm.

[0045] In an embodiment, the area of ​​the at least one second plastic scintillator blank is 100'000 mm 2 and 140'000mm 2 Between, preferably 110'000mm 2 and 130'000mm 2 between 12'000 mm and 12'000 mm, particularly preferably about 12'000 mm 2 In the embodiment with two, three or four transversely adjacent second plastic scintillator slabs, the total area of ​​the transversely adjacent second plastic scintillator slabs may be 100'000 mm 2 and 140'000mm 2 Between, preferably 110'000mm 2 and 130'000mm 2 between 1 and 20 mm, particularly preferably about 120'000 mm 2 .

[0046] In the context of the present invention, low energy gamma radiation is preferably understood to include gamma radiation having an energy between 30 keV and 150 keV, whereas high energy gamma radiation is preferably understood to include gamma radiation having an energy preferably above 150 keV.

[0047] In an embodiment, a panel radiation detector includes a thinner front panel having a plurality of laterally adjacent first plastic scintillator slabs and a thicker back panel having a single second plastic scintillator slab.

[0048] In an embodiment, the panel radiation detector comprises additional vertically stacked slabs whose thicknesses differ from each other and from those of the first and second slabs depending on the layer, the additional vertically stacked slabs forming additional layers, each layer having high sensitivity to a different range of gamma radiation energy.

[0049] In the same panel radiation detector, some of the scintillator slabs may abut laterally and some of the scintillator slabs may abut vertically.

[0050] In a preferred embodiment, the panel radiation detector comprises a joint signal processing board. Preferably, the processing unit and the analysis circuit are integrated on the joint signal processing board of the panel radiation detector to form an integrated signal processing system of the panel radiation detector.

[0051] In an embodiment, the panel radiation detector includes a joint analysis circuit connected to the digitization circuit and configured to perform signal analysis by performing the following steps: determining coincident digitized signals associated with radiation events, adding the coincident digitized signals associated with the radiation events, and determining the pulse width of the added signal to determine the energy of the radiation event. Thus, the joint analysis circuit can operate as the above-mentioned analysis circuit.

[0052] The advantage provided by using a joint analysis circuit for all or a group of processing units is that the cost can be reduced and the architecture of the panel radiation detector can be simplified while still enabling independent readout from the SiPM sensor. In an embodiment, the joint analysis circuit performs signal analysis on the detection signals of a group of 4 to 8 SiPM sensors. The coincidence logic applied by the joint analysis circuit can be used to determine the coincidence digitized signal associated with the radiation event. The coincidence logic is usually performed for a specific scintillator slab and requires two or more SiPM sensors to generate a 1-bit high response within a predefined coincidence time window, that is, the detection signal is above a threshold. Typically, the coincidence time window is between 10 and 100ns, but may vary depending on the specific application. Therefore, when a signal with an intensity exceeding a specific threshold appears within the predefined coincidence time window, the signals can be considered to be coincident. Determining the pulse width of the added signal digitized by the digitization circuit provides an efficient way to obtain spectral information and determine the energy of the radiation event. In particular, the joint analysis circuit can be configured to perform pulse width analysis when the detection signal as determined by the digitized signal of the digitization circuit is above the threshold. In order to obtain spectral information and determine the energy of the radiation event, in addition to the pulse width of the summed signal, characteristic attenuation components caused by the plastic scintillator material and / or components of the electronic circuit system can also be used.

[0053] In particular, determining the pulse width of the summed signal to obtain spectral information advantageously allows for simplified signal processing compared to obtaining energy information by determining the area under the signal.

[0054] In an embodiment, the joint analysis circuit is configured to perform a signal analysis of a detection signal, generated by the silicon photomultiplier tube sensor in response to detected scintillation light originating from the scintillator slab, for each scintillator slab, respectively.

[0055] Thus, an independent readout of each scintillator slab by a joint analysis circuit can be achieved, which allows to exploit the advantages of a segmented radiation detector, for example by correlating signals originating from different scintillator slabs.

[0056] In an embodiment, the panel radiation detector includes a pre-amplification circuit configured to pre-amplify the detection signal and a pulse shaping circuit configured to pulse shape the pre-amplified detection signal, wherein the digitization circuit is configured to perform 1-bit digitization of the pulse shaped detection signal.

[0057] Preferably, the processing units each comprising a pre-amplification circuit, a pulse shaping circuit and a digitization circuit and the joint analysis circuit are integrated on a single signal processing board of the panel radiation detector.

[0058] In an embodiment, the digitizing circuit comprises a discriminator arranged after the pulse shaping circuit.

[0059] The combination of the plastic scintillator slab and electronics, including digitizing circuitry configured to perform 1-bit digitization and joint analysis circuitry configured to perform pulse width analysis to obtain spectral information and determine energy, advantageously produces an efficient detection capability with high spectral resolution of detected radiation events. The panel radiation detector represents a cost-effective and highly sensitive radiation detection system using multiple plastic scintillators and multiple SiPM sensors that allows for independent readout of the plastic scintillators in an efficient manner.

[0060] In an embodiment, between two and eight, preferably between four and six, silicon photomultiplier tube sensors are arranged at the edge of at least one of the plastic scintillator slabs, preferably arranged in elongated strips and equidistantly spaced from each other.

[0061] In an embodiment, the strip comprises a first surface and an oppositely arranged second surface, wherein at least one of the SiPM sensors is arranged on the first surface and at least one of the SiPM sensors is arranged at the second surface of the strip. At least one of the SiPM sensors arranged at the first surface may be configured to detect scintillation light of a first scintillator slab, wherein at least one of the SiPM sensors arranged at the second surface may be configured to detect scintillation light of a second scintillator slab.

[0062] In an embodiment, the scintillator slabs are rectangular having long edges and short edges, wherein at least a portion of the scintillator slabs are adjacent along their long edges.

[0063] Alternatively or additionally, at least a portion of the scintillator slabs may abut along their short edges.

[0064] In an embodiment, the scintillator slab is rectangular with long edges and short edges, wherein a plurality of scintillator slabs abut a single scintillator slab by their short edges along the long edge of the single scintillator slab.

[0065] The scintillator slabs can be arranged in a flexible manner depending on the needs of radiation detection. Since SiPM sensors are small and universal in geometric arrangement, the arrangement of the scintillator slabs may not or only slightly be affected by the requirements of the SiPM sensors. In addition, the size of each scintillator slab can be designed differently, which increases the application range of the panel radiation detector. In addition to the rectangular design, in some embodiments, the scintillator slabs can have other polygonal shapes.

[0066] The signal processing components may be at least partially arranged on a signal processing board.For example, the signal processing board may be arranged at a common edge of at least a portion of the scintillator slab.

[0067] According to another aspect, the present invention also relates to a method for processing a detection signal of a panel radiation detector for detecting radiation events of ionizing radiation according to the present invention, the panel radiation detector comprising a plurality of adjacent plastic scintillator slabs, a plurality of silicon photomultiplier tube sensors arranged at the edge of at least one of the plastic scintillator slabs, and a plurality of signal processing units, each signal processing unit being connected to one of the silicon photomultiplier tube sensors and each comprising a digitization circuit, wherein the method comprises: detecting scintillation light generated in the scintillator slab by means of the silicon photomultiplier tube sensor; generating a detection signal by means of at least one of the silicon photomultiplier tube sensors in response to the detected scintillation light; and generating a digitized signal for signal analysis by performing 1-bit digitization of the detection signal by the digitization circuit to determine the energy of the detected radiation event.

[0068] Preferably, the panel radiation detector comprises analysis circuitry connected to the digitising circuitry, wherein the analysis circuitry uses the digitised signals of one or more of the digitising circuitry to determine an energy of a detected radiation event.

[0069] In an embodiment, the panel radiation detector includes a joint analysis circuit connected to the digitization circuit, wherein the joint analysis circuit performs signal analysis by performing the following steps: determining coincident digitized signals associated with the radiation event, adding the coincident digitized signals associated with the radiation event, and determining a pulse width of the added signal to determine the energy of the radiation event.

[0070] In an embodiment, the joint analysis circuit performs signal analysis of the detection signal generated by the silicon photomultiplier tube sensor in response to the detected scintillation light originating from the scintillator slab, respectively, for each scintillator slab.

[0071] In an embodiment, the panel radiation detector includes a pre-amplification circuit and a pulse shaping circuit, wherein the method further includes: pre-amplifying the detection signal by the pre-amplification circuit, pulse shaping the pre-amplified detection signal by the pulse shaping circuit, and performing 1-bit digitization on the pulse shaped detection signal by the digitization circuit.

[0072] Advantageously, sufficient statistics of the detection signal are aggregated so that a spectrum can be obtained. For example, if more than 100'000 entries are aggregated, then the statistics may be sufficient.

[0073] In an embodiment, the acquired spectrum is compared with a library stored in a data storage device so that the radiation source type can be identified.

[0074] The method comprising performing analog-to-digital conversion by 1-bit digitization of the detection signal and obtaining spectral information by a joint analysis circuit provides the advantages of a cost-effective signal processing method for a radiation detection system comprising one or more plastic scintillators and one or more SiPM sensors.

[0075] According to another aspect, the invention also relates to a radiation detection corridor comprising a plurality of panel radiation detectors according to the invention, wherein the radiation detection corridor comprises a first pillar, wherein a plurality of rows of panel radiation detectors are arranged successively on top of each other within the first pillar.

[0076] The small thickness of the panel radiation detector allows the panel radiation detector to be integrated into a millimeter wave body scanner and / or metal detector. By using a single pillar or wall, an "inductive wall" for detecting radiation sources carried by pedestrians can be provided. The radiation detection corridor can be advantageously used for border control and / or airport security, etc. The radiation detection corridor can also include millimeter wave imaging scanners, video cameras, etc.

[0077] In an embodiment, the radiation detection corridor further comprises a second pillar, wherein the plurality of rows of panel radiation detectors are sequentially arranged on top of each other within the second pillar, and wherein the first pillar and the second pillar define a radiation detection area therebetween.

[0078] The person being scanned may be located in the radiation detection area.Multiple row panel radiation detectors with individually readable scintillator slabs may be used to locate the radiation source on the person being scanned in the radiation detection corridor.

[0079] According to another aspect, the present invention also relates to a method for operating a radiation detection corridor according to the present invention, the method comprising processing detection signals of a panel radiation detector according to the method of the present invention, wherein the method further comprises locating an ionizing radiation source within the radiation detection corridor by associating the intensities of detection signals of silicon photomultiplier tube sensors of different rows.

[0080] Independent readout of the plastic scintillator slabs allows to perform a correlation analysis on the intensity of the detection signal and use the correlation information to locate the radiation source on the scanned person. A radiation source localized to a small area of ​​the person (e.g., around the person's feet) can point to a radiation threat and trigger further examination of the person. In contrast, a radiation source localizable to a large area (e.g., over the entire body of a person) can point to a radiation source such as that derived from nuclear medicine. Thus, a detected radiation event can be localized to the "center of gravity" of the radiation event that occurred, where a point-like center of gravity can point to a potential threat and a fuzzy center of gravity can point to a legitimate radiation source.

[0081] The advantage provided by radiation detection corridors is that the need for occupancy sensors such as used in radiation portal monitoring systems can be avoided. The fusion of the spatial positioning capability of the segmented panel radiation detectors with the data from the video cameras allows the scanning of continuous flows of goods or pedestrians respectively without the need to deploy occupancy sensors for detecting non-continuous occupancy in the corridor.

[0082] According to another aspect, the invention relates to a radiation detection drone comprising a panel radiation detector according to the invention.

[0083] When equipping a drone with radiation detection capabilities, the radiation detection sensitivity of each payload plays an important role. By providing a panel radiation detector installed in a drone, the sensitivity per unit weight can be optimally improved due to the small thickness of the plastic scintillator slab and the large area covered. Therefore, together with the lightweight and small SiPM sensor, the panel radiation detector allows the realization of an efficient and low-cost radiation detection drone.

[0084] In an embodiment, a panel radiation detector of a radiation detection drone comprises a central scintillator slab and at least two, preferably three or four peripheral scintillator slabs adjacent to the central scintillator slab on at least two of the edges of the central scintillator slab, wherein silicon photomultiplier tube sensors are arranged at the edge of the central scintillator slab and at the edge of at least one of the peripheral scintillator slabs.

[0085] Preferably, each scintillator slab features an edge in which a plurality of silicon photomultiplier tube sensors are arranged.

[0086] Arranging the plastic scintillator slabs in this manner and reading out each scintillator slab independently allows a radiation detection drone to extract directional information of the detected radiation.

[0087] In particular, the radiation detection drone may include a directionality unit configured to determine the directionality of incident ionizing radiation by correlating the intensity of a detection signal of a silicon photomultiplier tube sensor.

[0088] Determining the directionality of incident ionizing radiation can have the advantage that a radiation detection drone can reduce the area that the drone must scan. While a radiation detection drone with a conventional radiation detector must scan the entire area in a grid pattern, a radiation detection drone including a panel radiation detector according to the present invention can reduce the scanning pattern and approach the radiation source more directly due to the directional information. Therefore, the scanning time can be reduced, which allows for a larger radiation detector payload for the drone. BRIEF DESCRIPTION OF THE DRAWINGS

[0089] The invention will be explained in more detail by means of exemplary embodiments with reference to a schematic diagram, in which:

[0090] Figure 1 A schematic diagram of an embodiment of a panel radiation detector is shown in perspective view;

[0091] Figure 2 A schematic diagram showing an embodiment of a panel radiation detector in exploded view;

[0092] Figure 3 shows a block diagram of a SiPM sensor connected to a processing unit and an analysis circuit;

[0093] Figure 4 A schematic diagram of an embodiment of a panel radiation detector is shown in perspective view;

[0094] Figure 5 Two schematic diagrams showing embodiments of a radiation detection corridor including a plurality of panel radiation detectors;

[0095] Figure 6 A block diagram of an embodiment of a radiation detection drone including a panel radiation detector is shown;

[0096] Figure 7 shows the spectral response of a panel radiation detector according to the present invention;

[0097] Figure 8 A schematic diagram showing an embodiment of a radiation detection drone including a panel radiation detector;

[0098] Fig. 9 A schematic diagram of an embodiment of a panel radiation detector is shown in perspective view;

[0099] Fig.10 A schematic diagram showing the arrangement of plastic scintillator slabs of an embodiment of a panel radiation detector in perspective view;

[0100] Fig.11 A schematic diagram of an embodiment of a panel radiation detector is shown in a partially exploded view, wherein there is a Fig.10 Arrangement of plastic scintillator slabs;

[0101] Fig.12 A schematic diagram of an embodiment of a panel radiation detector is shown in perspective view;

[0102] Fig.13 A schematic diagram showing an example of shaping a detection signal. DETAILED DESCRIPTION

[0103] Figure 1 A schematic diagram of an embodiment of a panel radiation detector 10 is shown in perspective view. The panel radiation detector 10 comprises four plastic scintillator slabs 1, for example made of PVT, wherein two of the scintillator slabs 1 are each adjacent to each other at an interface or edge 12. SiPM sensor ( Figure 1 The scintillator slabs 1 are arranged at the edges 12 and also at the edges 13 of the scintillator slabs 1 that are not adjacent to other scintillator slabs 1. The scintillator slabs 1 have a rectangular shape and the interfaces between adjacent scintillator slabs 1 are formed along the short edges 12 of the scintillator slabs 1.

[0104] Figure 2 A portion of a panel radiation detector 10" is shown in an exploded view. The scintillator slabs 1" are vertically adjacent at their respective top and bottom surfaces. At the bottom surface or edge 12", strips 2" of printed circuit boards (PCBs) are arranged, respectively, on which four SiPM sensors 21" are arranged equidistantly. The SiPM sensors 21" are configured to detect scintillation light originating from the top scintillator slab 1". In the assembled configuration of the panel radiation detector 10", the strip 2" with the SiPM sensors 21" is therefore embedded between two scintillator slabs 1". The SiPM sensors 21" are connected to a signal processing board 3", which includes a processing unit and an analysis circuit assigned to each SiPM sensor 21".

[0105] Figure 3 A block diagram of a SiPM sensor 21 connected to a processing unit 331 and an analysis circuit 332 is shown. The processing unit 331 comprises a pre-amplification circuit 311 in which a detection signal from the SiPM sensor 21 is pre-amplified, a pulse shaping circuit 312 in which pulse shaping is performed on the pre-amplified signal, and a digitization circuit 313 in which the pulse shaped signal is digitized. The digitization circuit 313 is configured to perform 1-bit digitization. Each SiPM sensor 21 of the panel radiation detector presents a processing unit 331 assigned to the corresponding SiPM sensor 21. Thus, a SiPM processing unit block 21-331 is defined, which consists of Figure 3331. The three consecutive blocks 21-331 of the SiPM processing unit block can be part of a common stripe for detecting the scintillation light of a particular scintillation slab. The processing unit 331 or the digitizing circuit 313 is each connected to a joint analysis circuit 332. The analysis circuit 332 performs signal analysis by determining coincident digitized signals associated with radiation events, adding coincident digitized signals associated with radiation events, and determining the pulse width of the added signal to determine the energy of the detected radiation event. The analysis circuit 332 may include a field programmable gate array (FPGA), a microcontroller, a microprocessor, and / or other electronic circuit systems.

[0106] Figure 4 A schematic diagram of an embodiment of a panel radiation detector 10' is shown in a perspective view. The panel radiation detector 10' includes laterally adjacent plastic scintillator slabs 1a' and 1b'. The scintillator slab 1a' is larger than the scintillator slab 1b' and is adjacent to each other at the edge 12a'. The interface between the scintillator slabs 1a' is formed by the long edges 12a' of the adjacent scintillator slabs 1a'. The scintillator slabs 1b' are also adjacent to each other at their long edges 12b'. In addition, the scintillator slab 1b' is adjacent to one of the scintillator slabs 1a' at its short edge at the long edge of one of the scintillator slabs 1a'. At the common edge of the scintillator slab 1a' and one of the scintillator slabs 1b', a signal processing board 3' is arranged, which has a processing unit and a joint analysis circuit ( Figure 4 not shown).

[0107] Figure 5 Two schematic diagrams (a) and (b) of a radiation detection corridor 20 including a plurality of panel radiation detectors 210 are shown. The corridor 20 includes a first pillar 201 having panel radiation detectors 210 arranged in a row on top of each other and a second pillar 202 having panel radiation detectors 210 arranged in a row on top of each other. Figure 5 As shown in (a), person 4 is located in the radiation detection area defined between the first pillar 201 and the second pillar 202, and is screened by the panel radiation detector 210. The panel radiation detector 210 detects the radiation R emitted from person 4. By correlating the intensity of the detection signal of the SiPM sensor of the panel radiation detector 210, the radiation source 41 located at the foot of person 4 can be located. The positioning of the radiation source 41 at the small area of ​​the foot of person 4 points to an illegal radiation source. Figure 5 (b) shows another situation where person 4 is screened in radiation detection corridor 20 but does not carry an illegal radiation source. Panel radiation detector 210 detects radiation R, the source of which can be localized to person 4, but originates from the entire body of person 4. Figure 5 Compared to the situation in (a), localization to a large area points to legitimate radiation sources such as those from nuclear medicine.

[0108] Figure 6 A block diagram of a radiation detection drone 30 including a panel radiation detector 310 is shown. The panel radiation detector 310 includes a central scintillator slab 31a and four peripheral scintillator slabs 31b-e. Strips 32 with SiPM sensors 321 are arranged at corresponding interfaces between the central scintillator slab 31a and the peripheral scintillator slabs 31b-e. The SiPM sensors 321 are respectively arranged on the first surface and the second surface of each strip 2 or at the edge of each scintillator slab 31a-e, so that the scintillation light of the scintillator slabs 31a-e can be detected by the SiPM sensors 321 directed toward the corresponding scintillator slabs. The radiation detection drone 30 includes a directivity unit 301, which is configured to determine the directionality of the incident ionizing radiation by correlating the intensity of the detection signal of the SiPM sensor 321.

[0109] Figure 7 The measured spectral responses of a panel radiation detector according to the present invention to Na-22, CS-137, Co-60, and Th-232 are shown.

[0110] Figure 8 A schematic diagram of an embodiment of a radiation detection drone 30' including a panel radiation detector 310' is shown (only the portion of the drone 30' related to the panel radiation detector 310' is shown). The panel radiation detector 310' includes a central scintillator slab 31a' and two peripheral scintillator slabs 31b' and 31c'. The central scintillator slab 31a' is arranged in a plane perpendicular to the plane in which the peripheral scintillator slabs 31b' are arranged and perpendicular to the plane in which the peripheral scintillator slabs 31c' are arranged. Each scintillator slab 31a'-c' is characterized by an edge where a strip 32' is arranged. The strip 32' includes a plurality of SiPM sensors 321', which are arranged on the strip 32' and are configured to detect scintillation light originating from the corresponding scintillator slabs 31a'-c'. The panel radiation detector 310' also includes a signal processing board 33', which includes a processing unit and a joint analysis circuit assigned to the SiPM sensor 321'. The drone 30' includes a plastic support element 35' for supporting the structure of the signal processing board 33' and the panel radiation detector 310'.

[0111] Fig. 9A schematic diagram of an embodiment of a panel radiation detector 10'" is shown in a perspective view and a partially exploded view. The panel radiation detector 10'" comprises a plurality of plastic scintillator slabs 1'"' which are laterally adjacent to each other, thereby forming five groups 11'" of laterally adjacent plastic scintillator slabs 1'"'. The groups 11'"' are stacked on top of each other so that a multilayer panel radiation detector 10'"' is obtained. At each lateral edge of the group 11'"', a strip 2'"' comprising a plurality of SiPM sensors 21'"' is arranged, which are configured to detect scintillation light from each plastic scintillator slab 1'"'. The multilayer panel radiation detector 10'"' comprises a signal processing board 3'"', which includes a processing unit and a joint analysis circuit assigned to each SiPM sensor 21'"'.

[0112] Fig.10 A schematic diagram of the arrangement of plastic scintillator slabs 511 and 512 of an embodiment of a panel radiation detector 510 is shown in a perspective view. For simplicity, only the plastic scintillator slabs 511, 512 are shown, and other components of the panel radiation detector 510, such as, for example, SiPM sensors, are omitted in the figure. The panel radiation detector 510 includes four first plastic scintillator slabs 511 that are laterally adjacent to each other. The panel radiation detector 510 also includes a single second plastic scintillator slab 512, which is vertically stacked on top of the four first plastic scintillator slabs 511. In this context, it is clear to those skilled in the art that "top" does not mean an absolute direction in space, but is directed to the relative arrangement of the plastic scintillator slabs 511 and 512 with respect to each other. The thickness d1 of the four first plastic scintillator slabs 511 is less than the thickness d2 of the second plastic scintillator slabs 512. The four first plastic scintillator slabs 511 are part of the thinner front panel 5a and are optimized for detecting low-energy gamma radiation. The second plastic scintillator slab 512 is part of the thicker rear panel 5b and is optimized for detecting high energy gamma radiation. It is understood by those skilled in the art that for some embodiments, the illustrations shown in the accompanying drawings may represent a portion of the overall arrangement of plastic scintillator slabs 511, 512 such that the panel radiation detector 510 may effectively include more than four first plastic scintillator slabs 511. In addition, the panel radiation detector 510 may include more than a single second plastic scintillator slab 512. However, even in embodiments with more than a single second plastic scintillator slab 512, the number of first plastic scintillator slabs 511 is greater than the number of second plastic scintillator slabs 512.

[0113] Fig.11 A schematic diagram of an embodiment of a panel radiation detector 510 is shown in a partially exploded view, having a Fig.10The invention relates to an arrangement of a plurality of first plastic scintillator slabs 511 and a single second plastic scintillator slab 512. The first plastic scintillator slab 511 is part of a thinner front panel 5a, and the second plastic scintillator slab 512 is part of a thicker rear panel 5b. An elongated strip 52 of PCB with SiPM 521 is arranged at the lateral edges of the plastic scintillator slabs 511, 512. A signal processing board 53 is arranged next to the second plastic scintillator slab 512. An inlet protection wall 54 is arranged next to the thinner front panel 5a and faces the monitoring area of ​​the panel radiation detector 510. Therefore, low-energy gamma radiation from a radiation source located next to the inlet protection wall 54 in the monitoring area of ​​the panel radiation detector 510 first hits the thinner front panel 5a, where the low-energy gamma radiation can be detected due to scintillation in the first plastic scintillator slab 511. However, high energy gamma radiation from the radiation source passes through the thinner front panel 5 a substantially unattenuated and impinges on the thicker rear panel 5 b where it can be detected due to scintillation in the second plastic scintillator slab 512 .

[0114] Fig.12 A schematic diagram of an embodiment of a panel radiation detector 610 is shown in perspective view. The panel radiation detector 610 comprises four plastic scintillator slabs 61, for example made of PVT, which are adjacent to each other at interfaces or edges 612. Fig.12 The SiPM sensors are connected to a signal processing board 63, which includes a processing unit assigned to each SiPM sensor and an analysis circuit contained in a protective box 64.

[0115] Fig.13 Schematic diagrams of examples of shaping pulses or detection signals are shown respectively. The original scintillator pulse is shown as dashed line A. The SiPM sensor that detects the scintillation light of the scintillator pulse A generates an electrical pulse or signal, respectively, as shown by dashed line B. The electrical signal from the SiPM sensor is pulse shaped by the pulse shaping circuit to obtain a pulse shaped signal as shown by the solid line C, which can be digitized by the digitization circuit.

[0116] Bulleted List

[0117] 10,10',10",10"',210,310,310',510,610 Panel Radiation Detector

[0118] 20 Radiation Detection Corridor

[0119] 201 First Pillar

[0120] 202 Second Pillar

[0121] 30,30' Radiation Detection Drone

[0122] 301 Directional Unit

[0123] 35' Plastic Support Element

[0124] 1,1a'-b',1",1"',31a-e,31a'-c',511,512,61 Plastic scintillator slab

[0125] 11”' Group

[0126] 12,12a'-b',12",612 edge

[0127] 13,613 Edge

[0128] 2,2”,2”',32,32',52,62 Strips

[0129] 21,21”,21"',321,321',521 SiPM Sensor

[0130] 3,3',3",3"',33',53,63 Signal Processing Board

[0131] 331 Signal Processing Unit

[0132] 311 Pre-amplifier circuit

[0133] 312 Pulse Shaping Circuit

[0134] 313 Digital Circuit

[0135] 332 Joint Analysis Circuit

[0136] 21-331 SiPM Processing Unit Block

[0137] 4 people

[0138] 41 Radiation Source

[0139] 5a Thinner front panel

[0140] 5b Thicker rear panel

[0141] 54 Inlet protection wall

[0142] 64 Protective box

[0143] R Radiation

Claims

1. A panel radiation detector (10, 10', 10", 10'", 210, 310, 310', 510, 610) for detecting a radiation event of ionizing radiation (R), comprising a plurality of adjacent plastic scintillator slabs (1, 1a'-b', 1", 1'", 31a-e, 31a'-c', 511, 512, 61), arranged at an edge (12, 12a'-b', 12", 13, 613) of at least one of the plastic scintillator slabs (1, 1a'-b', 1", 1'", 31a-e, 31a'-c', 511, 512, 61) and configured to detect radiation events in response to the radiation events on the plastic scintillator slabs (1, 1a'-b', 1", 1'", 31a-e, 31a'-c', 511, 512, 61). The invention relates to a plurality of silicon photomultiplier tube sensors (21, 21", 21'", 321, 321', 521) for detecting scintillation light generated in the plastic scintillator blank (a, b, 1", 1'", 31a-e, 31a'-c', 511, 512, 61), and a plurality of signal processing units (331), each of which is connected to one of the silicon photomultiplier tube sensors (21, 21", 21'", 321, 321'), wherein the aspect ratio d / l and / or d / w of the plastic scintillator blank is lower than 1, wherein d is the thickness of the plastic scintillator blank, l is the length of the plastic scintillator blank and w is the width of the plastic scintillator blank, wherein the signal processing units (331) each include a digitized circuit A digitizing circuit (313) is configured to generate a digitized signal for signal analysis to determine the energy of the detected radiation event by performing 1-bit digitization on a detection signal generated by at least one of the silicon photomultiplier tube sensors (21, 21", 21'", 321, 321', 521) in response to detected scintillation light, wherein the panel radiation detector (10, 10', 10", 10'", 210, 310, 310', 510, 610) includes a joint analysis circuit (332) connected to the digitizing circuit (313) and configured to perform the signal analysis by performing the following steps: determining a coincident digitized signal associated with the radiation event, Coincident digitized signals associated with radiation events are added, and the pulse width of the added signal is determined to determine the energy of the radiation event; and wherein the joint analysis circuit (332) is configured to perform signal analysis of the detection signal separately for each plastic scintillator slab (1, 1a'-b', 1", 1"', 31a-e, 31a'-c', 511, 512, 61), wherein the detection signal is generated by the silicon photomultiplier tube sensor (21, 21", 21"', 321, 321', 521) in response to the detected scintillation light originating from the plastic scintillator slab (1, 1a'-b', 1", 1"', 31a-e, 31a'-c', 511, 512, 61).

2. The panel radiation detector (10, 10', 10", 10'", 210, 310, 310', 510, 610) according to claim 1, characterized in that: The panel radiation detector (10, 10', 10", 10'", 210, 310, 310', 510, 610) includes a pre-amplification circuit (311) configured to pre-amplify a detection signal and a pulse shaping circuit (312) configured to pulse shape the pre-amplified detection signal, wherein a digitization circuit (313) is configured to perform 1-bit digitization on the pulse-shaped detection signal.

3. The panel radiation detector (10, 10', 10", 10'", 210, 310, 310', 510, 610) according to claim 1 or 2, characterized in that: Between two and eight silicon photomultiplier tube sensors (21, 21", 21'", 321, 321', 521) are arranged at an edge (12, 12a'-b', 12", 13, 613) of at least one of the plastic scintillator slabs (1, 1a'-b', 1", 1"', 31a-e, 31a'-c', 511, 512, 61).

4. The panel radiation detector (10, 10', 10", 10'", 210, 310, 310', 510, 610) according to claim 3, characterized in that: The silicon photomultiplier tube sensors (21, 21", 21'", 321, 321', 521) are equidistantly spaced from each other.

5. The panel radiation detector (10, 10', 10", 10'", 210, 310, 310', 510, 610) according to claim 1 or 2, characterized in that: Between four and six silicon photomultiplier tube sensors (21, 21", 21'", 321, 321', 521) are arranged at an edge (12, 12a'-b', 12", 13, 613) of at least one of the plastic scintillator slabs (1, 1a'-b', 1", 1"', 31a-e, 31a'-c', 511, 512, 61).

6. The panel radiation detector (10, 10', 10", 10'", 210, 310, 310', 510, 610) according to claim 5, characterized in that: The silicon photomultiplier tube sensors (21, 21", 21'", 321, 321', 521) are equidistantly spaced from each other.

7. The panel radiation detector (10, 10', 10", 10'", 210, 310, 310', 510, 610) according to claim 3, characterized in that: The silicon photomultiplier tube sensors (21, 21", 21'", 321, 321', 521) are arranged on an elongated strip (2, 2", 2'", 32, 32', 52, 62).

8. The panel radiation detector (10, 10', 10", 10'", 210, 310, 310', 510, 610) according to claim 1 or 2, characterized in that: The plastic scintillator slab (1, 1a'-b', 1", 1"', 31a-e, 31a'-c', 511, 512, 61) is rectangular with long edges and short edges, wherein at least a portion of the plastic scintillator slab (1, 1a'-b', 1", 1"', 31a-e, 31a'-c', 511, 512, 61) are adjacent along their long edges.

9. The panel radiation detector (10') according to claim 1 or 2, characterized in that: The plastic scintillator slab (1a'-b') is rectangular with long edges and short edges, wherein a plurality of plastic scintillator slabs (1a'-b') are adjacent to a single plastic scintillator slab (1a'-b') along its long edge by its short edges.

10. The panel radiation detector (10, 10', 10", 10'", 210, 310, 310', 510, 610) according to claim 1 or 2, characterized in that: At least two plastic scintillator blanks (1, 1a'-b', 1", 1"', 31a-e, 31a'-c', 511, 61) are laterally adjacent to each other.

11. The panel radiation detector (10", 10'", 510, 610) according to claim 1 or 2, wherein at least two plastic scintillator slabs (1", 1'", 511, 512) are stacked vertically on top of each other.

12. The panel radiation detector (510, 610) according to claim 1, characterized in that: The panel radiation detector (510, 610) includes at least one first plastic scintillator slab (511) and at least one second plastic scintillator slab (512), which are vertically stacked on top of each other, wherein the thickness (d1) of the at least one first plastic scintillator slab (512) is less than the thickness (d2) of the at least one second plastic scintillator slab (512).

13. The panel radiation detector (510, 610) according to claim 12, characterized in that: The thickness (d2) of the at least one second plastic scintillator slab (512) is 4 to 20 times greater than the thickness (d1) of the at least one first plastic scintillator slab (511).

14. The panel radiation detector (510, 610) according to claim 12, characterized in that: The thickness (d2) of the at least one second plastic scintillator slab (512) is 6 to 15 times greater than the thickness (d1) of the at least one first plastic scintillator slab (511).

15. The panel radiation detector (510, 610) according to claim 12, characterized in that: The thickness (d2) of the at least one second plastic scintillator slab (512) is 8 to 10 times greater than the thickness (d1) of the at least one first plastic scintillator slab (511).

16. The panel radiation detector (510, 610) according to any one of claims 12 to 15, characterized in that: The thickness (d1) of the at least one first plastic scintillator slab (511) is 1-4 times of one side of an active area of ​​one of the silicon photomultiplier tube sensors (521) arranged at the edge of the at least one first plastic scintillator slab (511).

17. The panel radiation detector (510, 610) according to any one of claims 12 to 15, characterized in that: The thickness (d1) of the at least one first plastic scintillator slab (511) is 1-2 times of one side of an active area of ​​one of the silicon photomultiplier tube sensors (521) arranged at the edge of the at least one first plastic scintillator slab (511).

18. The panel radiation detector (510, 610) according to any one of claims 12 to 15, characterized in that: The thickness (d1) of the at least one first plastic scintillator blank (511) is between 3 mm and 15 mm.

19. The panel radiation detector (510, 610) according to any one of claims 12 to 15, characterized in that: The thickness (d1) of the at least one first plastic scintillator slab (511) is between 5 and 10 mm.

20. The panel radiation detector (510, 610) according to any one of claims 12 to 15, characterized in that: The panel radiation detector (510, 610) comprises a thinner front panel (5a) having a plurality of laterally adjacent first plastic scintillator slabs (511) and a thicker rear panel (5b) having a single second plastic scintillator slab (512).

21. A method for processing a detection signal of a panel radiation detector (10, 10', 10", 10'", 210, 310, 310', 510, 610) for detecting a radiation event of ionizing radiation, wherein the panel radiation detector (10, 10', 10", 10'", 210, 310, 310', 510, 610) comprises a plurality of adjacent plastic scintillator slabs (1, 1a'-b', 1", 1"', 31a-e, 31a'-c', 511, 512, 61), arranged in the plastic scintillator slabs (1, 1a'-b', 1", 1'", 31a-e, 31a'-c', 511, 512, 61) a plurality of silicon photomultiplier tube sensors (21, 21", 21'", 321, 321', 521) at at least one edge (12, 12a'-b', 12", 13, 613) of the plastic scintillator blank, and a plurality of signal processing units (331), each signal processing unit (331) being connected to one of the silicon photomultiplier tube sensors (21, 21", 21'", 321, 321', 521) and each comprising a digitizing circuit (313), wherein the aspect ratio d / l and / or d / w of the plastic scintillator blank is lower than 1, wherein d is the thickness of the plastic scintillator blank, l is the length of the plastic scintillator blank and w is the width of the plastic scintillator blank, wherein the method comprises: Detecting scintillation light generated in a plastic scintillator blank (1, 1a'-b', 1", 1"', 31a-e, 31a'-c', 511, 512, 61) by a silicon photomultiplier tube sensor (21, 21", 21'", 321, 321', 521); generating a detection signal by at least one of the silicon photomultiplier tube sensors (21, 21", 21"', 321, 321', 521) in response to the detected scintillation light; generating a digitized signal for signal analysis by performing 1-bit digitization of the detection signal by a digitization circuit (313) to determine the energy of the detected radiation event, wherein the panel radiation detector (10, 10', 10", 10'", 210, 310, 310', 510, 610) includes a joint analysis circuit (331) connected to the digitization circuit (313) 2), wherein the joint analysis circuit (332) performs signal analysis by performing the following steps: determining coincident digitized signals associated with radiation events, adding coincident digitized signals associated with radiation events, and determining a pulse width of the added signal to determine the energy of the radiation event; and wherein the joint analysis circuit (332) performs signal analysis of a detection signal separately for each plastic scintillator slab (1, 1a'-b', 1", 1"', 31a-e, 31a'-c', 511, 512, 61), wherein the detection signal is generated by a silicon photomultiplier tube sensor (21, 21", 21"', 321, 321', 521) in response to detected scintillation light originating from the plastic scintillator slab (1, 1a'-b', 1", 1"', 31a-e, 31a'-c', 511, 512, 61).

22. The method according to claim 21, characterized in that The panel radiation detector (10, 10', 10", 10'", 210, 310, 310', 510, 610) comprises a pre-amplification circuit and a pulse shaping circuit, wherein the method further comprises: pre-amplifying the detection signal by the pre-amplification circuit, pulse shaping the pre-amplified detection signal by the pulse shaping circuit, and performing 1-bit digitization on the pulse-shaped detection signal by the digitization circuit (313).

23. A radiation detection corridor (20) comprising a plurality of panel radiation detectors (210) according to one of claims 1 to 20, wherein the radiation detection corridor (20) comprises a first pillar (201), wherein a plurality of rows of panel radiation detectors (210) are arranged sequentially on top of each other within the first pillar (201).

24. The radiation detection corridor (20) according to claim 23, characterized in that: The radiation detection corridor (20) also includes a second pillar (202), wherein multiple rows of panel radiation detectors (210) are arranged sequentially on top of each other within the second pillar (202), and wherein the first pillar and the second pillar (201; 202) define a radiation detection area between the first pillar and the second pillar (201; 202).

25. A method for operating a radiation detection corridor (20) according to claim 23 or 24, the method comprising processing a detection signal of a panel radiation detector (210) according to claim 21 or 22, characterized in that The method also includes locating an ionizing radiation source (41) within the radiation detection corridor (20) by correlating the intensities of detection signals from different rows of silicon photomultiplier tube sensors.

26. A radiation detection drone (30, 30') comprising a panel radiation detector (310) according to any one of claims 1 to 20.

27. The radiation detection drone (30, 30') according to claim 26, characterized in that: The panel radiation detector (310, 310') includes a central scintillator slab (31a, 31a') and at least two peripheral scintillator slabs (31b-e, 31b'-c') adjacent to the central scintillator slab (31a, 31a') on at least two of its edges, wherein a silicon photomultiplier tube sensor (321, 321') is arranged at the edge of the central scintillator slab (31a, 31a') and at the edge of at least one of the peripheral scintillator slabs (31b-e, 31b'-c').

28. The radiation detection drone (30, 30') according to claim 26, characterized in that: The panel radiation detector (310, 310') includes a central scintillator slab (31a, 31a') and three or four peripheral scintillator slabs (31b-e, 31b'-c') adjacent to the central scintillator slab (31a, 31a') on at least two of its edges, wherein silicon photomultiplier tube sensors (321, 321') are arranged at the edge of the central scintillator slab (31a, 31a') and at the edge of at least one of the peripheral scintillator slabs (31b-e, 31b'-c').

29. The radiation detection drone (30, 30') according to claim 27, characterized in that: The radiation detection drone (30, 30') includes a directionality unit (301) configured to determine the directionality of incident ionizing radiation by correlating the intensity of a detection signal of a silicon photomultiplier tube sensor (321, 321').

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