阅读说明：本技术 中微子探测器装置、中微子探测器系统和探测中微子的方法 (Midamicron detector device, Midamicron detector system and method for detecting Midamicron ) 是由 R·施特劳斯 J·罗特 D·豪夫 于 2017-04-11 设计创作，主要内容包括：一种用于探测中微子的中微子探测器装置(100),包括至少一个目标探测器(10),其包括目标晶体(11)和目标温度传感器(12),目标晶体(11)用于响应于待探测的中微子与目标晶体(11)的相互作用而产生声子,目标温度传感器(12)用于响应于在目标晶体(11)中产生的声子的吸收而感测温度变化；内否决探测器(20),其包括具有内否决温度传感器(23)的至少一个内否决组件(21),其中,所述至少一个内否决组件(21)适于支撑所述至少一个目标探测器(10),并且适于通过响应于背景相互作用事件而产生声子并利用内否决温度传感器(23)响应于声子的吸收而感测温度变化,来进行基于反符合的α和β背景相互作用事件的判别；以及用于容纳内否决探测器(20)的外否决探测器(30),其中,所述外否决探测器(30)包括至少一个外否决组件(31),其响应于与γ和中子背景的相互作用而产生声子并具有外否决温度传感器(33),外否决温度传感器(33)用于响应于在所述至少一个外否决组件(31)中产生的声子的吸收而感测温度变化,其中,所述中微子探测器装置(100)被配置用于在低温下操作,所述至少一个目标探测器(10)的目标晶体(11)的晶体体积和目标温度传感器(12)的尺寸被选择为使得所述至少一个目标探测器(10)的地上灵敏度阈值低于180eV,并且所述至少一个内否决组件(21、26)包围所述至少一个目标探测器(10),使得所述至少一个目标探测器(10)布置在内否决探测器(20)内。此外,描述了一种包括中微子探测器装置的中微子探测器系统和探测中微子的方法,其中,使用了中微子探测器装置(100)。(A mesoparticle detector arrangement (100) for detecting mesoparticles, comprising at least one target detector (10) comprising a target crystal (11) and a target temperature sensor (12), the target crystal (11) being adapted to generate phonons in response to interaction of the mesoparticle to be detected with the target crystal (11), the target temperature sensor (12) being adapted to sense temperature changes in response to absorption of phonons generated in the target crystal (11), an inner overrule detector (20) comprising at least one inner overrule component (21) with an inner overrule temperature sensor (23), wherein the at least one inner overrule component (21) is adapted to support the at least one target detector (10) and to carry out an anti-coincidence based α and β background interaction event by generating phonons in response to the background interaction event and sensing temperature changes with the inner overrule temperature sensor (23) in response to absorption of phonons, and an outer overrule detector (30) for accommodating the inner overrule detector (20), wherein the outer overrule detector (30) is configured with at least one inner overrule detector (10) for detecting a target crystal temperature change in response to at least one overrule detector (31) and at least one overrule detector (31) is configured to detect a target crystal temperature change in response to the target crystal (10, wherein the target crystal (10) and the target overrule detector (10) is configured such that the target crystal (31) is configured to detect at least one overrule detector (31) and the target crystal (10) is configured to detect at least one overrule detector (31) and the target crystal (10) is configured to detect at least one overrule detector (20) and the target crystal (20) to detect at least one overrule detector (20) when the target crystal (20) is configured to detect at least one overrule detector (20) and the target crystal (20) is configured to detect at least.)

1. A mesoparticle detector device (100) configured for detecting a mesoparticle, the mesoparticle detector device (100) comprising

-at least one target detector (10) comprising a target crystal (11) and a target temperature sensor (12), the target crystal (11) being adapted to generate phonons in response to interaction of mesogens to be detected with the target crystal (11), the target temperature sensor (12) being arranged for sensing temperature changes in response to absorption of phonons generated in the target crystal (11), and

-an internal rejection detector (20) comprising at least one internal rejection assembly (21, 21A, 21B, 26A, 26B) having an internal rejection temperature sensor (23), wherein the at least one internal rejection assembly (21, 21A, 21B, 26A, 26B) is adapted to support the at least one target detector (10) and to perform an anti-coincidence based discrimination of a background interaction event by generating phonons in response to the background interaction event and sensing temperature changes with the internal rejection temperature sensor (23) in response to absorption of the phonons, wherein

-the mesoscopic detector arrangement (100) is configured for operation at cryogenic temperatures,

it is characterized in that

-the crystal volume of the target crystal (11) of the at least one target detector (10) and the dimensions of the target temperature sensor (12) are selected such that the above-ground sensitivity threshold of the at least one target detector (10) is below 180eV,

-the at least one internal veto assembly (21, 21A, 21B, 26A, 26B) encloses the at least one object detector (10) such that the at least one object detector (10) is arranged within an internal veto detector (20), and

-an outer overrule detector (30) is provided for accommodating the inner overrule detector (20), wherein the outer overrule detector (30) comprises at least one outer overrule component (31), the at least one outer overrule component (31) being adapted to generate phonons in response to interaction with background radiation and having an outer overrule temperature sensor (33), the outer overrule temperature sensor (33) being arranged for sensing temperature changes in response to absorption of phonons generated in the at least one outer overrule component (31).

2. The neutron detector device of claim 1, wherein

-the crystal volume of the target crystal (11) of the at least one target detector (10) and the dimensions of the target temperature sensor (12) are selected such that the above-ground sensitivity threshold of the at least one target detector (10) is below 100eV, in particular below 50 eV.

3. A mesoparticle detector arrangement according to any of the preceding claims, wherein,

-the target crystal (11) of the at least one target detector (10) has a cubic shape.

4. A neutron detector device according to claim 3, wherein

-the target crystal (11) has an edge length below 10 mm.

5. A mesodetector arrangement according to any preceding claim wherein

-the target temperature sensor (12) of the at least one target detector (10) is a transition edge sensor.

6. A mesodetector arrangement according to any preceding claim wherein

-an array (13) of a plurality of object detectors (10) is arranged within the inner reject detector (20).

7. The neutron detector device of claim 6, wherein

-the target crystal (11) of the target detector (10) is made of a common wafer assembly.

8. A mesoparticle detector arrangement as claimed in any preceding claim wherein the mesoparticle detector arrangement further comprises

-at least one reference target detector (40) arranged within the internal rejection detector (20) and comprising a reference target crystal adapted to generate phonons in response to background interaction events and a reference target temperature sensor arranged for sensing temperature changes in response to absorption of phonons generated in the reference target crystal.

9. The neutron detector device of claim 8, wherein

-both the target crystal (11) and the reference target crystal comprise light nuclei.

10. A neutron detector device according to claim 8 or 9, wherein

-an array (43) of a plurality of reference object detectors (40) is arranged within the inner overruling detector (20).

11. A mesodetector arrangement according to any preceding claim wherein

-the at least one internal veto component (21, 21A, 21B, 26A, 26B) of the internal veto detector (20) encloses the at least one object detector (10) in all spatial directions.

12. A mesodetector arrangement according to any preceding claim wherein

-the at least one internal veto component (21, 21A, 21B, 26A, 26B) of the internal veto detector (20) comprises a monocrystalline wafer.

13. A mesodetector arrangement according to any preceding claim wherein

-the at least one internal veto component (21, 21A, 21B, 26A, 26B) of the internal veto detector (20) comprises a silicon or sapphire wafer.

14. A neutron detector device according to claim 12 or 13, wherein

-the at least one internal veto component (21, 21A, 21B, 26A, 26B) of the internal veto detector (20) has a thickness in the range of 10 μm to 1 mm.

15. A mesodetector arrangement according to any preceding claim wherein

-at least two inner reject assemblies (21A, 21B) of an inner reject detector (20) are arranged on opposite sides of the at least one target detector (10), wherein the inner reject assemblies (21A, 21B) have a first support element (24) clamping the at least one target detector (10) in between.

16. A mesodetector arrangement according to any preceding claim wherein

-the internal veto detector (20) comprises at least one passive support assembly (22), the at least one passive support assembly (22) being adapted to support the at least one internal veto assembly (21A, 21B, 26A, 26B) via a second support element (25).

17. A neutron detector device according to claim 15 or 16, wherein the first and second support elements (24, 25) provide contact surfaces, the dimensions of the contact surfaces being such that

-the thermal coupling between the target crystal (11) of the at least one target detector (10) and the internal veto component (21A, 21B) is negligible compared to the thermal coupling from the target crystal (11) of the at least one target detector (10) to the surrounding hot bath structure via the target temperature sensor (12), and/or

-the thermal coupling between the at least one internal veto component (21A, 21B) of the internal veto detector (20) and the passive support component (22) is negligible compared to the thermal coupling from the at least one internal veto component (21A, 21B) of the internal veto detector (20) to the surrounding hot bath structure via the internal veto temperature sensor (23).

18. A neutron detector device according to claim 17, wherein the neutron detector device comprises a plurality of electrodes

-the first and second support elements (24, 25) provide point-like contact surfaces.

19. A mesoparticle detector arrangement according to any of the preceding claims, wherein,

-the at least one outer reject component (31) of the outer reject detector (30) is made of a single crystal material.

20. A mesoparticle detector arrangement according to any of the preceding claims, wherein,

-the outer overrule detector (30) comprises at least two outer overrule assemblies (31) forming a container enclosing the inner overrule detector (20).

21. A mesodetector arrangement according to any preceding claim wherein

-the target crystal (11) of the at least one target detector (10) is adapted to generate photons in response to background interaction events in the target crystal (11), and

-the internal rejection detector (20) is adapted to detect photons.

22. A mesoparticle detector system (200), said mesoparticle detector system (200) comprising

-at least one mesoparticle detector device (100) according to any of the preceding claims,

a cooling arrangement (210) arranged for cooling the at least one mesogen detector arrangement (100),

-a vacuum device (220) arranged for evacuating the at least one mesogen detector device (100), and

-a control device (230) coupled with the target temperature sensor (12) of the at least one target detector (10), the at least one inner overrule temperature sensor (23) of the inner overrule detector (20) and the at least one outer overrule temperature sensor (33) of the outer overrule detector (30).

23. The mesoparticle detector system of claim 22, wherein the mesoparticle detector system further comprises

-a generator arrangement (240) arranged for powering and operating the in-flight micro sub-detector system independently of the stationary grid.

24. The mesoscopic detector system of claim 22 or 23, wherein the mesoscopic detector system is comprised on a moving carrier device (250) or in a stationary container (260).

25. A method of detecting a neutron, the method comprising the steps of:

-providing a mesodetector device (100) according to any of claims 1 to 20 in an environment (300) to be investigated,

-collecting sensor signals of a target temperature sensor (12) of at least one target detector (10), at least one inner reject temperature sensor (23) of an inner reject detector (20) and at least one outer reject temperature sensor (33) of an outer reject detector (30) as a function of time, and

-analyzing the collected sensor signals to identify mesoparticle scattering events in the at least one target detector (10).

26. The method of claim 25, wherein

-the mesoscopic detector arrangement (100) is operated above ground.

27. The method of claim 25 or 26, wherein

-the environment (300) to be investigated comprises a nuclear power plant (310).

28. The method according to any one of claims 25 to 27, wherein the method comprises the steps of:

-arranging a mesogen detector arrangement (100) at least two different detection positions having different distances to a target location in an environment (300) to be investigated,

-collecting sensor signals at the different detection positions, and

-analyzing the collected sensor signals, wherein the background condition is characterized by differences in the collected sensor signals at the different detection positions.

Technical Field

The present invention relates to a mesoparticle detector device for detecting mesoparticles based on their interaction with heavy nuclei in a target crystal operating at low temperature.

The invention further relates to a mesoparticle detector system comprising at least one mesoparticle detector arrangement and to a method for detecting a mesoparticle using a mesoparticle detector arrangement. The application of the invention can be used for studying mesogens, in particular in above-ground environments, for example in monitoring nuclear power plants, in research experiments or in geological formations.

Background

In the present specification, the technical background of the present invention is described with reference to the following prior arts:

[1] christensen et al, "Phys rev.lett." volume 113, 2014, page 042503;

[2]EP 0 102 398B1；

[3] drukier et al, Phys Rev.D, Vol.20, 1984, p.2295; and

[4] strauss et al, Nuclear Instruments & Methods in Physics Research A volume 845, 2017, page 414 and 4172016; and

[5]F.

et al, J.Low.Temp.Phys. "Vol.100 (12), 1995, pages 69-104.

It is well known that mesogens react with substances only via weak interactions, which are one of the four basic interactions known in nature. Therefore, the mesogens are isotropic away from the source and are not affected by surrounding materials. Which makes them ideal sources of information, for example, for monitoring nuclear reactions. As an example of monitoring artificial nuclear reactions, anti-neutrino monitoring for heavy water reactors has been proposed in document [1 ]. However, detecting mesogens is challenging because they have no charge and a substantially zero mass.

In basic studies, for example for studying the flux of mesogens from outer space or the nuclear reaction in accelerators, mesogen detectors with a large target mass of several hundred tons are used. As an example, through the interaction of neutrinos with a target substance, photons are generated, which are sensed by a photosensor. These detectors operate underground to shield against background radiation, such as cosmic radiation. Due to size and subsurface operation, this type of mesoparticle detector is not suitable for monitoring artificial nuclear reactions with time resolution, for example in nuclear power plants.

In documents [2] and [3], a compact meson-micron probe including a superconducting semiconductor target material has been proposed. Through the interaction of the mesogens with the target material, a change in the resistivity of the target material is induced, which can be sensed as an indication of the mesogen interaction event. Although this type of mesodetector would allow operation on the ground, even mobile operations, for example for studying radioactive geological sources, it would have a great disadvantage in terms of a limited sensitivity threshold (energy threshold).

Not only for neutron detectionDetectors with low sensitivity thresholds are required, but also for example in dark matter searches. In [4]]The dark matter detector disclosed in (1) comprises CaWO having the dimensions 20mm by 10mm₄A target crystal and a temperature sensor. The temperature sensor is a transition edge sensor (document [5 ]]). Phonons that induce a measurable temperature change are generated in the temperature sensor in response to the interaction of meson or dark material particles with the target crystal. The target crystal is prepared from CaWO₄A rod support, which is also provided with a temperature sensor. CaWO₄The rods are arranged along a single spatial direction relative to the target crystal. CaWO₄The wand is used for discrimination of background interaction events based on anti-coincidence (overruling the detector). By operating at low temperatures, an above ground sensitivity threshold of 190eV is obtained. Further, in document [4]]A sensitivity threshold of 50eV was estimated, which would provide detection of neutrons. However, this energy threshold can only be found in document [4]]The detector disclosed in (a) is obtained in underground operation and is therefore not suitable for above ground neutrino detection.

Disclosure of Invention

Object of the Invention

It is an object of the present invention to provide an improved mesoparticle detector arrangement and method which avoids the limitations of conventional detector technology, in particular to provide an improved sensitivity threshold, for example to allow detection of mesoparticles above ground, and/or to provide improved background rejection. Furthermore, it is an object of the present invention to provide an improved mesoscopic sub-detector system, comprising at least one mesoscopic sub-detector device, which avoids the limitations of conventional detector systems, and in particular allows mobile operation in a research environment.

Drawings

Further details and advantages of the invention are described below with reference to the accompanying drawings, in which:

FIG. 1: a schematic cross-sectional view of a preferred embodiment of a mesodetector arrangement of the present invention;

FIG. 2: the cross section of the target detector and the internal rejection detector of the micro-neutron detector device is shown in the invention;

FIG. 3: a schematic perspective view of an enlarged array of object detectors;

FIG. 4: a schematic perspective view of further details of one embodiment of a mesodetector arrangement of the present invention;

FIG. 5: a schematic diagram of a preferred embodiment of a mesodetector system of the present invention;

fig. 6A and 6B: a schematic diagram of a mesoscopic detector system arranged in an environment to be studied; and

fig. 7 and 8: a graph of simulation results showing the advantages of the present invention is shown.

Detailed Description

The features of the preferred embodiment of the invention are described below with reference to the details of the neutron detector device, in particular its structure and arrangement of detectors. The features of the mesoscopic sub-detector system comprising the mesoscopic sub-detector arrangement, such as the details of the cooling and vacuum means, are not described, since they are for example known from the prior art. In the following, reference will be made to a neutron detector system for monitoring a nuclear power plant. The invention is not limited to this application but may also be used to monitor neutrino sources of other man-made or natural origin, for example in laboratory experiments or other tests, or at geological sites including radioactive geological formations or in celestial particle detection. In the following, the term "comprising" will be used in the context of CaWO-based₄For exemplary reference, a medium micro sub-detector system of the object detector of (1). The invention is not limited to this material but may be used with heavy nuclei, especially W or Mo, e.g. PbWO₄、ZnWO₄、CsI、CdWO₄、CaMoO₄、CdMoO₄Or ZnMoO₄And (3) other crystals.

FIG. 1 shows a schematic diagram of a meson detector arrangement 100 of the present invention, the meson detector arrangement 100 comprising three separate cryogenic detectors 10, 20 and 30, each operated as a calorimeter, the combination of an inner target detector 10 with both an inner reject detector 20 that detects decay of surfaces α and β and an outer reject detector 30 that detects neutrons and gamma photons, significantly reducing background levels in the target detector 10.

The target detector 10 includes a single target crystal 11 (fig. 1) or an array 13 (fig. 2, 3, 4) of multiple target crystals 11 provided with a target temperature sensor 12. The target crystal 11 is a cubic crystal having an edge length of, for example, 5 mm. It consists of a single crystal CaWO comprising W as the heavy nucleus₄(e.g., mass 0.76 g).

Target temperature sensor 12 is TES deposited on one surface of target crystal 11, e.g. from document [4]]Are known in (a). It includes a phonon collector membrane 14 (made of Al, e.g., 1 μm in thickness, e.g., 0.15mm in area)²) And a sensor film 15 (made of W, e.g., 200nm in thickness, e.g., 0.0061mm in area)²). The phonon collector membrane 14 increases the phonon collection area without increasing the thermal capacity of the sensor [4]Thereby resulting in an increased output pulse height. The target temperature sensor 12 is made of Au (e.g., 0.01X 7.0mm in size) via a strip 16²Thickness: 20nm) is weakly coupled to the surrounding hot bath structure (heat sink). The strip is wire bonded via Au to one of the passive support components of the internal rejection probe 20 described below and provides a thermal conductivity of about 10pW/K (at a temperature of 10 mK). Wire bonds (made of Al) having a diameter of, for example, 25 μm are used to provide electrical contacts for the target temperature sensor 12 (bonded on the phonon collector) and the ohmic heater 17 (separate bond pads), respectively. Typically, a bias current of between 100nA and 50 μ a is applied to the target temperature sensor 12. The change in resistance of the target temperature sensor 12 can be measured with a SQUID (Superconducting quantum interference Device) system, as described in, for example, reference [4]]As described in (1).

Performance model predictions prepared by the inventors are for CaWO₄The energy threshold of the target detector 10 of the target crystal is about 6.5 eV. In order to obtain a more efficient overall target quality, a 3 x 3 detector array 13 as shown in fig. 2 and 4 may be foreseen. This corresponds to CaWO₄The total target mass of (2) was 6.84 g.

The internal veto detector 20 includes an internal veto assembly 21 that surrounds the target detector 10 and provides active discrimination of β and α decays on the surface of the volume surrounding the target crystal 11 typical Q values for such decays are between about 10keV to 10MeV, typically shared between 2, 3 or more product particles in configurations where the target crystal 11 is surrounded by a 4 π active veto, the total energy of the reaction (minus the energy transmitted to the neutrino in the β decay) is detected so that a high fraction of such background can be rejected by coincidence events in the internal veto detector 20.

The internal negative assembly 21 comprises, for example, a single crystal Si wafer having a thickness of, for example, 400 μm. Each internal veto assembly 21 has an internal veto temperature sensor 23 disposed on a surface of the corresponding internal veto assembly 21. Preferably, the internal veto temperature sensor 23 is similar in construction to the target temperature sensor 12 described above, but is sized to accommodate the size of the corresponding internal veto assembly 21. In particular, the internal veto temperature sensor 23 is weakly coupled to the surrounding hot bath structure (heat sink) via a strip wire-bonded to one of the passive support components of the internal veto probe 20. The inner veto assembly 21 supports the object detector 10 via a first support element 24, and the inner veto assembly 21 is supported by a passive support assembly via a second support element (not shown in fig. 1), as described below with reference to fig. 2.

The outer overrule detector 30 comprises an outer overrule component 31 which surrounds the inner overrule detector 20 and provides active discrimination of neutron scattering events and gamma radiation. In a preferred embodiment, two single crystals of Ge or CaWO are provided₄The outer reject assembly 31 is formed as a box-shaped or hollow cylindrical container that houses the inner reject detector 20 (see fig. 4). The wall thickness of the outer reject probe 30 is for example 30mm to 60 mm. Each outer reject assembly 31 has an outer reject temperature sensor 33 disposed on a surface of the corresponding outer reject assembly 31. Preferably, the construction of the outer overrule temperature sensor 33 is similar to the target temperature sensor 12 described above, but is adapted to the larger size of the outer overrule assembly.

According to fig. 2, the object detector 10 comprises an array 13 of a plurality of identical object crystals 11, each arranged as described with reference to fig. 1. Fig. 2 is a schematic cross-sectional view. The complete array 13 comprises 3 x 3 target crystals 11, which are arranged in an array plane perpendicular to the drawing plane. The target crystal 11 is surrounded by internal overruling components 21A, 21B, 26A, 26B (shown in black), the internal overruling components 21A, 21B, 26A, 26B being held by passive support components 22 (hatched).

Each target crystal 11 is, for example, 5X 5mm with TES (not shown)³The calorimeter cube of (1). The internal veto assemblies 21A, 21B, 26A, 26B are Si wafers equipped with TES (as described with reference to FIG. 1) and providing 4 π surface veto. Two of the internal veto elements 21A, 21B (flat plates parallel to the array plane) have a first support element 24, such as a pyramid or truncated pyramid, with a height of, for example, 200 μm, which is preferably produced by wet-chemical etching of these internal veto elements 21A, 21B. These first support elements 24 directly hold the target crystal 11. One of the internal negative components (e.g., 21B) in direct contact with the target crystal is flexible due to a thickness of only 200 μm. The internal veto assembly 21B functions as a spring. Pressing on the target crystal 11, it achieves a spring loaded retention structure that compensates for thermal contraction of the various components of the internal rejection detector 20. Possible events caused by the internal veto detector 20 (e.g. by thermal stress relaxation) that induce phonons in the TES of the internal veto components 21A, 21B may be countered. Another internal negative component (e.g., 21A) in direct contact with the target crystal is not flexible and it has an opening 27A for wire bonding. The remaining inner veto components 26A, 26B are not in direct contact with the target crystal 11, but are arranged to completely surround the array 13.

The passive support assembly 22 is a Si or sapphire wafer without a temperature sensor, for example, 2mm thick. The inner negative component 21A, 21B, 26A, which is parallel to the array plane, is supported by the passive support component 22 via a second support element 25, e.g. a sapphire ball with a diameter of e.g. 1 mm. The second support elements 25 may be adhesively attached to the respective passive support assemblies 22, or they may be received in a receptacle hole of smaller diameter than the second support elements 25. The passive support assembly 22 presses the inner parts together. A further inner overruling component 26B perpendicular to the array plane is arranged at a distance from the passive support component 22, thereby enclosing the side view line from the target crystal 11 and allowing its pressing function. To this end, the internal veto assembly 26B is supported by an additional flexible retainer (not shown). An opening 27B is provided in the passive support assembly 22 for passage of the wire bonds 18 of a target temperature sensor (not shown). In addition, passive support assembly 22 carries wires connected to wire bonds 18.

The internal negative subassembly 21A, 21B, 26A, 26B and the passive support assembly 22 are held together by means of a mechanical connector 28 (shown in fig. 4), said mechanical connector 28 comprising, for example, a screw, acting only on the passive support assembly 22. The inner veto assembly 21A, 21B, 26A, 26B is held indirectly by the mechanical connector 28 via the passive support assembly 22.

The array 13 of object detectors may comprise more object crystals 11, as schematically shown in fig. 3 an arrangement of 15 x 15 object crystals 11 each with an object temperature sensor 12. Preferably, all target crystals 11 have the same composition, for example by manufacturing them from one common wafer. As described with reference to fig. 2, the target crystal 11 is held between the inner overruling assemblies 21A, 21B by a first support element (not shown). The upper inner veto assembly 21A is shown with an opening 27A for passage of a wire bond (as shown in fig. 2).

Fig. 4 shows more details of the inventive meso-micro sub-detector arrangement 100 in the open state, the meso-micro sub-detector arrangement 100 having an array 13 of object detectors 10, an inner reject detector (partially shown) and an outer reject detector. The array 13 of object detectors 10 comprises 3 x 3 object crystals as described above. Furthermore, an array 43 (schematically shown) of reference object detectors 40 is provided. Array 43 includes 3 × 3 reference target crystals, each of which is arranged like a target crystal with TES (not shown), but in contrast to the target crystal, e.g., CaWO₄And another material, such as sapphire. Preferably CaWO₄(e.g., 0.76g) and sapphire (e.g., 0.49g) crystals, because of their excellent low temperature detector performance. The total mass of the sapphire array 43 is, for example, 4.41 grams. The reference target crystal is arranged in a reference array plane parallel to the array plane of the target detector 10In (1). The two detector arrays 13, 43 and the inner reject detector 20 are mounted in a Ge or CaWO assembly having at least two cup-shaped outer reject assemblies 31 having a diameter of, for example, 10cm and a height of, for example, 5cm₄Within the external reject detector, each component is equipped with an external reject temperature sensor and operates as a cryogenic detector.

With the object detector 10 and the reference object detector 40, a multi-target method with multiple sensitive crystals is provided, which is particularly advantageous for separating the signal and the background by characteristic interaction intensities. This advantage is further illustrated in fig. 7 described below.

A schematic diagram of a mesoscopic sub-detector system 200 of the present invention is schematically shown in fig. 5. The neutron detector system 200 comprises a neutron detector device 100 of the present invention, a cooling device 210, a vacuum device 220, a control device 230, and a generator device 240. The cooling device 210 is, for example, a dilution refrigerator cryostat, which is capable of adjusting the temperature of the mesogen detector device 100 to, for example, 5 mK. The vacuum device 220 includes a vacuum pump 221, such as a turbo-molecular pump, connected to a vacuum chamber 222 cooled by the cooling device 210. The neutron detector device 100 is arranged at a vacuum pressure lower than 10^-7To 10^-8In a vacuum chamber 222 of hPa. The generator device 240 is, for example, a diesel generator having an output of, for example, 10 kW.

The control means 230 comprises computer circuitry arranged to receive an output signal from the temperature sensor of each probe 10, 20, 30. The output signal may be transmitted by wire or by wireless communication. Each temperature sensor provides a separate output channel. In the case of an array of target crystals 11 (see fig. 1, 4) and the number of inner veto modules 21A, 21B, 26A and outer veto modules 31, for example up to 20 output channels are connected to the control device 230. In more detail, the control means 230 is arranged for storing a time series of output signals of each output channel and performing a coincidence analysis on the time series. Only signal events occurring in the output signal of the target temperature sensor are assigned to the mesoscopic sub-scattering events. The control means 230 is further arranged for controlling the components 210, 220 and 240.

Fig. 6 schematically illustrates the application of the present invention in monitoring a nuclear power plant 310 (the reactor core is the target site to be monitored). The one or more than two mesodetector systems 200 are located on at least one mobile carrier device 250 that is movable in the environment 300 of the nuclear power plant 310, for example in a range of 15m to 100m or more, for example up to 500m from the reactor core (fig. 6A), or in at least one stationary container 260 arranged in a building 320 and/or in the nuclear power plant 310 (fig. 6B). Advantageously, the building 320 is additionally shielded from the cosmic background. Fig. 6 shows a mesoscopic sub-detector system 200 operating in the ground. Alternatively, the mesoscopic detector system 200 can also be operated underground.

By moving the moving carrier device 250 and/or by using a plurality of stationary mesogen detector systems 200 (fig. 6B) at different positions, the mesogens can be detected at different detection positions. Since mesoparticle interactions with materials are extremely low, the output signals of detectors 10 to 30 at different detection positions differ according to different background conditions and the known inverse square law of mesoparticle flux with respect to distance from the source of mesoparticles. Thus, performing coincidence analysis on the output signals at different detection positions allows for additional background suppression.

Fig. 7 shows an example of the output signals of a meson-micronaire detector arrangement 100 comprising an array 13, 43 of object detectors and reference object detectors as shown in fig. 4. The expected count rate of medium and micro-sub scattering events from a nuclear power plant, e.g. 4GW, is shown. The black dashed line represents an example of background levels from measurement and simulation. Curve A shows a curve based on CaWO₄While curve B shows the Al-based neutron recoil energy based on the neutron recoil energy₂O₃Reference target detector count rate. Advantageously, in CaWO₄In the case of (1), the output signal at low and medium-micro-neutron recoil energy is 2 to 3 orders of magnitude higher than background, while at Al₂O₃The ratio of signal to background is much smaller (1-5 times). FIG. 7 shows that the strong material dependence of the count rate is used to distinguish between mesoparticle signals and irreducibleA powerful tool for the background. CaWO₄And Al₂O₃Is significantly different, for example at 10eV, the ratio is about 50: 1. in contrast, background counts from external gamma radiation are comparable (within about 2 times). Furthermore, the neutron background will produce a similar spectrum, since in both materials-for neutron induced scattering-due to kinematics the dominant O-scattering is above the energy threshold.

Curve a of fig. 8 shows the significance of detecting a medium micro-sub scattering event (CNNS event) according to the measurement time with the medium micro-sub detector arrangement 100 of fig. 4 based on likelihood analysis with a sensitivity threshold of 10 eV. The simulation results represent measurements in the nuclear power plant 310 as shown in FIG. 6B. The dashed line shows the level of detection of statistical significance of CNNS events used in scientific experiments. Advantageously, significant neutrino detection can be obtained within about 2 days of detector operation. This represents a significant advance over conventional detection techniques in view of the use of detectors having a total mass of about 10 g. In particular, fig. 8 shows the potential of the present invention for reliably detecting neutrino in a short measurement time.

The features of the invention disclosed in the above description, the drawings and the claims may be of significance individually, in combination or in sub-combination for the implementation of the invention in its different embodiments.