Self-powered radiation detector

Abstract

To provide a self-powered radiation detector that is less susceptible to common mode noise than conventional ones and is easy in portable operation.SOLUTION: A self-powered radiation detector includes a meatal emitter 11, a collector 12, a current measuring unit 16, conductor wire 15 for electrically connecting the emitter 11 and the current measuring unit 16, a housing frame 17 housing the current measuring unit 16, and an electron supply unit 18 that supplies electrons to the current measuring unit 16. The emitter 11, collector 12, current measuring unit 16, conductor wire 15, housing frame 17, and electron supply unit 18 are insulated from ground 61, and the current measuring unit 16 measures current flowing between the electron supply unit 18 and the emitter 11.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a self-powered radiation detector for monitoring dose rates. [Background technology]

[0002] As an example of a gamma ray detection device that can detect gamma rays with high sensitivity even in a low dose rate environment, Patent Document 1 describes a gamma ray measurement device that includes an emitter, a collector arranged outside the emitter, a current measuring device connected to the emitter, and an electron inflow path that allows electrons generated in the collector to flow into the emitter, wherein the collector is formed of a material that has a higher probability of interacting with gamma rays than the emitter, and relatively more electrons are generated from the collector than from the emitter. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-165665 Summary of the Invention [Problem to be solved by the invention]

[0004] Self-powered radiation detectors are used to detect radiation. To areas that react with radiation It does not require a power supply such as the application of a voltage. This is a radiation detector that measures the current that flows when the number of electrons in the material that makes up the detector changes due to irradiation with radiation.

[0005] Depending on the type of radiation being measured, they are called self-powered gamma ray detectors (SPGDs) or self-powered neutron detectors (SPNDs).

[0006] In the present invention, the explanation will be mainly given taking SPGD as an example, but the basic concept and structure are the same for SPND.

[0007] In SPGD, electrons are ejected from the emitter, which is part of the detector, when irradiated with gamma rays, resulting in a decrease in the number of electrons in the emitter. To replenish the electrons that have been removed, electrons are supplied to the emitter via a conductor connected to the emitter. An electric current flows as the electrons move through this conductor.

[0008] The source of the moving electrons is earth, as described in the above-mentioned patent application WO 02 / 04499.

[0009] In the configuration of a self-powered radiation detector, a configuration has been disclosed in which the emitter and collector are connected to ground and the current between the emitter and ground is measured. Also known is a configuration in which the current generated when electrons emitted from the emitter are collected by the collector is measured.

[0010] Thus, standard self-powered radiation detectors must be replenished with electrons from earth.

[0011] However, as a result of intensive investigations by the present inventors, the following circumstances have become clear.

[0012] A configuration that supplies electrons from the earth inevitably requires wired operation, which makes it susceptible to common mode noise via the ground wire and makes portable operation difficult.

[0013] On the other hand, simply insulating it from the earth will prevent electrons from being replenished, so some kind of countermeasure must be taken.

[0014] The present invention provides a self-powered radiation detector that is less susceptible to the effects of common mode noise than conventional detectors and is portable and easy to operate. [Means for solving the problem]

[0015] The present invention includes multiple means for solving the above problems, and one example thereof is a device comprising a metallic emitter, a collector, a current measuring unit, a first conductor electrically connecting the emitter and the current measuring unit, a housing frame that houses the current measuring unit, and an electron supply unit that supplies electrons to the current measuring unit, wherein the emitter, the collector, the current measuring unit, the first conductor, the housing frame, and the electron supply unit are insulated from earth, and the current measuring unit measures the current flowing between the electron supply unit and the emitter. [Effects of the Invention]

[0016] According to the present invention, it is possible to provide a self-powered radiation detector that is less susceptible to the effects of common mode noise than conventional detectors and that is portable and easy to operate. Other problems, configurations, and effects will become clear from the following description of the embodiments. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a diagram showing a schematic configuration of a self-powered radiation detector of Example 1. FIG. [Figure 2] FIG. 10 is a diagram showing a schematic configuration of a self-powered radiation detector according to a second embodiment. [Figure 3] FIG. 10 is a diagram showing a schematic configuration of a self-powered radiation detector according to a third embodiment. [Figure 4] FIG. 10 is a diagram showing a schematic configuration of a self-powered radiation detector according to a fourth embodiment. [Figure 5] FIG. 10 is a diagram showing a schematic configuration of a self-powered radiation detector according to a fifth embodiment. [Figure 6] FIG. 10 is a diagram showing a schematic configuration of a self-powered radiation detector according to a sixth embodiment. [Figure 7] FIG. 10 is a diagram showing a schematic configuration of a self-powered radiation detector according to a seventh embodiment. [Figure 8] FIG. 13 is a diagram showing a schematic configuration of a self-powered radiation detector according to an eighth embodiment. [Figure 9] FIG. 13 is a diagram showing a schematic configuration of a self-powered radiation detector according to a ninth embodiment. [Figure 10]FIG. 20 is a diagram showing a schematic configuration of a self-powered radiation detector of Example 10. [Figure 11] FIG. 16 is a diagram showing a schematic configuration of a self-powered radiation detector of Example 11. DETAILED DESCRIPTION OF THE INVENTION

[0018] Hereinafter, embodiments of the self-powered radiation detector of the present invention will be described with reference to the drawings. In the drawings used in this specification, identical or similar reference numerals are used to designate identical or corresponding components, and repeated description of these components may be omitted.

[0019] Example 1 A first embodiment of a self-powered radiation detector according to the present invention will be described with reference to Fig. 1. Fig. 1 is a diagram showing the basic concept of a self-powered gamma ray detector (SPGD) according to this embodiment.

[0020] The self-powered radiation detector 1 shown in FIG. 1 includes an emitter 11, a collector 12, insulating materials 13, 14, and 20, a current measuring unit 16, a conductor 15 that electrically connects the emitter 11 and the current measuring unit 16, a housing frame 17 that houses the current measuring unit 16, an electron supply unit 18 that supplies electrons to the current measuring unit 16, and a conductor 19.

[0021] In this embodiment, in the self-powered radiation detector 1, at least the emitter 11, collector 12, current measuring unit 16, conductor 15, housing frame 17, and electron supply unit 18 are insulated from the earth 61. Note that while the self-powered radiation detector 1 is measuring radiation, at least all of the above components of the self-powered radiation detector 1 must be insulated from the earth 61, but there are no particular limitations when radiation is not being measured, and they may or may not be electrically connected to the earth.

[0022] The emitter 11 is a member made of metal such as lead (Pb), and is secured to the collector 12 placed outside it with a space therebetween, or an insulating material is provided to prevent contact between them. The emitter 11 is electrically connected to a conductor 15.

[0023] The collector 12 or the metal electrically connected to the collector 12 is structured so as not to come into contact with the conductor 15 due to the insulating material 13 .

[0024] The current measuring unit 16 is a measuring device that measures the current flowing between the emitter 11 and the conductor 19 connected to the electron supply unit 18, which is a lump of metal such as iron, and essentially measures the current flowing between the electron supply unit 18 and the emitter 11.

[0025] Conductive wire 15 is insulated from housing frame 17 of current measuring unit 16 by insulating material 14. Similarly, conductive wire 19 is insulated from housing frame 17 housing current measuring unit 16 by insulating material 20.

[0026] The housing frame 17 may be made of either metal or non-metal, and is not particularly limited.

[0027] Although the collector 12 may be made of a non-metallic material, it is preferable that the collector 12 be made of a metal in order to avoid self-absorption of electrons in the emitter 11.

[0028] In such a self-powered radiation detector 1, when gamma rays are irradiated, an interaction occurs between the gamma rays and the emitter 11, and electrons are ejected from the emitter 11. Examples of interactions that ultimately result in electrons being ejected from the emitter 11 include the photoelectric effect, Compton scattering, and electron pair creation.

[0029] As the electrons are ejected, the number of electrons in the emitter 11 decreases, so electrons move from the electron supply unit 18 via the conductors 19 and 15 to compensate for the electrons, generating a current. This current is measured by the current measurement unit 16.

[0030] Since the amount of electrons generated is proportional to the amount of radiation irradiated, the amount of radiation (gamma rays) irradiated to the emitter 11 of the self-powered radiation detector 1 can be determined from the measured current value.

[0031] Next, the effects of this embodiment will be described.

[0032] The self-powered radiation detector 1 of the above-described first embodiment of the present invention comprises a metallic emitter 11, a collector 12, a current measurement unit 16, a conductor 15 electrically connecting the emitter 11 and the current measurement unit 16, a housing frame 17 that houses the current measurement unit 16, and an electron supply unit 18 that supplies electrons to the current measurement unit 16, and the emitter 11, collector 12, current measurement unit 16, conductor 15, housing frame 17, and electron supply unit 18 are insulated from earth 61, and the current measurement unit 16 measures the current flowing between the electron supply unit 18 and the emitter 11.

[0033] This eliminates the need for earth connection 61, making it possible to avoid the effects of common mode noise from peripheral devices, and to provide an SPGD that can be operated in a portable state, which was previously difficult.

[0034] Furthermore, since the electron supply unit 18 is a metal mass, it can supply a sufficient amount of electrons that will not cause any problems in measurement in many cases.

[0035] <Example 2> Second Embodiment A self-powered radiation detector according to a second embodiment of the present invention will be described with reference to Fig. 2. Fig. 2 is a diagram showing a schematic configuration of the self-powered radiation detector according to the second embodiment.

[0036] The self-powered radiation detector 1A of this embodiment shown in FIG. 2 is configured to supply electrons from an electron supply unit 18A to a current measurement unit 16A via a housing frame 17A.

[0037] The electron supply unit does not necessarily need to be electrically connected to the current measurement unit through a lead wire.

[0038] In FIG. 2, the housing frame 17A is made of metal, and the electronic supply unit 18A and the housing frame 17A are in physical contact with each other, thereby electrically connecting the housing frame 17A and the electronic supply unit 18A.

[0039] In this configuration, when electrons are repelled from emitter 11, the electrons move from electron supply unit 18A to emitter 11 via housing frame 17A and conductor 15. At this time, the current measurement unit 16A measures the value of the current flowing between housing frame 17A and conductor 15. In other words, the current measurement unit 16A measures the current flowing between electron supply unit 18A and emitter 11 via housing frame 17A. The radiation dose irradiated to emitter 11 of self-powered radiation detector 1A is calculated from the measured current value.

[0040] The other configurations and operations are substantially the same as those of the self-powered radiation detector 1 of the first embodiment described above, and the details are omitted here.

[0041] The self-powered radiation detector 1A of the second embodiment of the present invention also provides substantially the same effects as those of the self-powered radiation detector 1 of the first embodiment described above.

[0042] In the second embodiment, the movement of electrons in the collector 12 does not contribute to the current to be measured, so the collector 12 does not need to be metallic and may be non-metallic.

[0043] Example 3 A self-powered radiation detector according to a third embodiment of the present invention will be described with reference to Fig. 3. Fig. 3 is a diagram showing a schematic configuration of the self-powered radiation detector according to the third embodiment.

[0044] The self-powered radiation detector 1B of this embodiment shown in FIG. 3 has a configuration in which a collector 12B and an electron supply section 18B are electrically connected to each other.

[0045] 3, the device is insulated from earth 61 and further includes a conductor 21B connecting metal collector 12B and current measurement unit 16B, providing electrical continuity between collector 12B and electron supply unit 18B. In addition, current measurement unit 16B measures the current flowing between collector 12B and emitter 11 via conductor 21B and metal housing frame 17B.

[0046] Here, the case where the conductor 21B is electrically connected to the housing frame 17B is shown, but as shown in Figure 1, a conductor (corresponding to conductor 19) may be provided to connect the electron supply unit 18B and the current measurement unit 16B (insulated from the housing frame 17B), and this conductor may be connected to the collector 12B.

[0047] With this configuration, measuring the value of the current flowing between conductor 15 and conductor 21B is equivalent to measuring the value of the current flowing between emitter 11 and electron supply unit 18B. With this configuration, the current value measured by current measurement unit 16B correlates with the amount of radiation irradiated to self-powered radiation detector 1B, so it is possible to determine the amount of radiation irradiated to emitter 11 of self-powered radiation detector 1B.

[0048] The other configurations and operations are substantially the same as those of the self-powered radiation detector 1 of the first embodiment described above, and the details are omitted here.

[0049] The self-powered radiation detector 1B of the third embodiment of the present invention also provides substantially the same effects as the self-powered radiation detector 1 of the first embodiment described above.

[0050] Moreover, the device is insulated from earth 61 and further includes a conductor 21B connecting collector 12B and current measurement unit 16B, and collector 12B and electron supply unit 18B are electrically connected, and current measurement unit 16B can measure the current flowing between collector 12B and emitter 11 to release electrons from collector 12B to electron supply unit 18B, thereby preventing collector 12B from becoming electrically charged and realizing more accurate radiation dose measurement. Furthermore, since electrons can be supplied to electron supply unit 18B, radiation dose measurement can be performed over a longer period of time.

[0051] In this embodiment as well, the movement of electrons in the collector 12B does not contribute to the current to be measured, so the collector 12B does not need to be metallic and may be non-metallic.

[0052] Furthermore, if there is an electrically conductive metal body such as scaffolding around the collector 12B, the accumulation of electrons can be suppressed, and therefore there is less need to provide the conductive wire 21B. Such a solution is suitable for the self-powered radiation detectors 1 and 1A of the first and second embodiments described above.

[0053] Example 4 A self-powered radiation detector according to a fourth embodiment of the present invention will be described with reference to Fig. 4. Fig. 4 is a diagram showing a schematic configuration of the self-powered radiation detector according to the fourth embodiment.

[0054] A self-powered radiation detector 1C of this embodiment shown in FIG. 4 is configured to replenish electrons from an electron replenishment section 18C via a collector 12C.

[0055] In the self-powered radiation detector 1C of this embodiment, an electron supply unit 18C is physically connected to a metal collector 12C, and electrons are exchanged between the electron supply unit 18C and the collector 12C, and are input to a current measuring unit 16C via a conductor 21C.

[0056] The other configurations and operations are substantially the same as those of the self-powered radiation detector 1 of the first embodiment described above, and the details are omitted here.

[0057] The self-powered radiation detector 1C of the fourth embodiment of the present invention also provides substantially the same effects as those of the self-powered radiation detector 1 of the first embodiment described above.

[0058] The electron supply unit 18C and the collector 12C do not need to be in direct physical contact with each other, and the same effect can be obtained if they are electrically connected via a conductor, etc. In this embodiment, the housing frame 17C may be made of metal or non-metal, and is not particularly limited.

[0059] <Example 5> A self-powered radiation detector according to a fifth embodiment of the present invention will be described with reference to Fig. 5. Fig. 5 is a diagram showing a schematic configuration of the self-powered radiation detector according to the fifth embodiment.

[0060] The self-powered radiation detector 1D of this embodiment shown in Figure 5 has a configuration in which the conductor wire 15 is eliminated, the collector 12D and the housing frame 17D are made of metal, and the electron supply unit 18D and the housing frame 17D are electrically connected.

[0061] In the configuration of Figure 5, electrons are emitted from emitter 11 when emitter 11 is irradiated with gamma rays. To compensate for these electrons, electrons are supplied to emitter 11 from housing frame 17D. The value of the current generated at this time is measured by current measurement unit 16D. Electrons moving from housing frame 17D to emitter 11 are supplied from collector 12D or electron supply unit 18D.

[0062] That is, it can be understood that the collector 12D, the housing frame 17D, and the electron supply portion 18D form a large electron supply portion.

[0063] The other configurations and operations are substantially the same as those of the self-powered radiation detector 1 of the first embodiment described above, and the details are omitted here.

[0064] The self-powered radiation detector 1D of the fifth embodiment of the present invention also provides substantially the same effects as the self-powered radiation detector 1 of the first embodiment described above.

[0065] The electron supply unit 18D may be physically connected to the collector 12D instead of the housing frame 17D. The collector 12D may be made of a non-metallic material.

[0066] Example 6 A self-powered radiation detector according to a sixth embodiment of the present invention will be described with reference to Fig. 6. Fig. 6 is a diagram showing a schematic configuration of the self-powered radiation detector according to the sixth embodiment.

[0067] The self-powered radiation detector 1E of this embodiment shown in FIG. 6 has a configuration in which the metal around the current measuring section 16E serves as the electron supply section.

[0068] 6 is made of metal, and if this housing frame 17E can be made of a metal with a sufficiently large capacity, then housing frame 17E can take the place of the electron supply unit, i.e., housing frame 17E and the electron supply unit can be integrated. Note that if, in addition to housing frame 17E, metal collector 12E and housing frame 17E are electrically connected as shown in FIG. 6, collector 12E can also be considered to be integrated with the electron supply unit.

[0069] FIG. 6 shows an example in which the housing frame 17E is made of a sufficiently large metal, and even if the collector 12E is non-metallic or if there is no conductor 21E between the self-powered radiation detector 1E and the current measuring unit 16E, the amount of radiation irradiated onto the self-powered radiation detector 1E can be measured from the current value obtained by the current measuring unit 16E.

[0070] As shown in FIG. 6, when a metal collector 12E and a housing frame 17E are electrically connected via a conductor 21E, the collector 12E can also serve as an electron supply section.

[0071] The other configurations and operations are substantially the same as those of the self-powered radiation detector 1 of the first embodiment described above, and the details are omitted here.

[0072] The self-powered radiation detector 1E of the sixth embodiment of the present invention also provides substantially the same effects as those of the self-powered radiation detector 1 of the first embodiment described above.

[0073] Furthermore, since the housing frame 17E is made of metal and the housing frame 17E and the electronic supply unit are integrated, there is no need to provide a separate electronic supply unit, and the configuration can be further simplified.

[0074] Example 7 A self-powered radiation detector according to a seventh embodiment of the present invention will be described with reference to Fig. 7. Fig. 7 is a diagram showing a schematic configuration of the self-powered radiation detector according to the seventh embodiment.

[0075] The self-powered radiation detector 1F of this embodiment shown in FIG. 7 is configured to be operated without the system up to the data output being connected to earth, and is equipped with an insulated data output unit 31.

[0076] As described above, in the present invention, the presence of the electron supply unit 18 and the like eliminates the need to supply electrons to the system, and therefore the earth 61 does not need to be connected.

[0077] Therefore, the self-powered radiation detector 1F of this embodiment is insulated from the earth 61 and further includes an insulated data output unit 31, which transfers the measured current value as data.

[0078] In the self-powered radiation detector 1F, the electron supply unit 18F is connected to the conductor 21F, and the current measurement unit 16F measures the value of the current flowing between the conductor 21F and the conductor 15. There is an insulating material 22 between the conductor 21F and the housing frame 17F, so there is no electrical continuity, and the current measurement unit 16F measures the current flowing from the collector 12 and the electron supply unit 18F to the emitter 11.

[0079] Information on the measured current value is sent from the insulated data output unit 31 to the data receiving unit 32 via the data communication wiring 33 and is recorded in the data recording device 41 .

[0080] Examples of the insulated data output unit 31 include wireless communication such as wireless LAN and data communication methods that do not use metal wires such as optical fibers.

[0081] Other than that, the operations of the self-powered radiation detector 1F, the current measuring unit 16F, etc. are the same as those described above.

[0082] The other configurations and operations are substantially the same as those of the self-powered radiation detector 1 of the first embodiment described above, and the details are omitted here.

[0083] The self-powered radiation detector 1F of the seventh embodiment of the present invention also provides substantially the same effects as those of the self-powered radiation detector 1 of the first embodiment described above.

[0084] In addition, it is insulated from the earth 61 and further includes an insulated data output unit 31, which is insulated by transferring the measured current value as data, thereby isolating the data output system from the earth 61 and enabling the radiation measurement to be separated with higher accuracy from common mode noise that sneaks in from the power supply system, thereby further reducing the risk of noise contamination.

[0085] The conductive wire 21F is not essential and can be omitted.

[0086] Example 8 A self-powered radiation detector according to an eighth embodiment of the present invention will be described with reference to Fig. 8. Fig. 8 is a diagram showing a schematic configuration of the self-powered radiation detector according to the eighth embodiment.

[0087] The self-powered radiation detector 1G of this embodiment shown in FIG. 8 is configured such that a battery 34 that supplies power to a current measuring unit 16G and an insulated data output unit 31 serves as an electron supply unit.

[0088] As shown in FIG. 8, in the self-powered radiation detector 1G, power is supplied to the current measuring section 16G and the insulated data output section 31 from a battery 34 via a power supply wire 35 and a power supply wire 36, respectively.

[0089] The current measuring unit 16G measures the current flowing from the cathode of the battery 34 to the emitter 11. At this time, the collector 12 and the housing frame 17G may be electrically connected to the cathode of the battery 34. Information on the measured current value is sent by the insulated data output unit 31 to the data receiving unit 32 via the data communication wiring 33, and is recorded in the data recording device 41.

[0090] The other configurations and operations are substantially the same as those of the self-powered radiation detector 1 of the first embodiment described above, and the details are omitted here.

[0091] The self-powered radiation detector 1G of the eighth embodiment of the present invention also provides substantially the same effects as those of the self-powered radiation detector 1 of the first embodiment described above.

[0092] In addition, the electronic supply unit is a battery 34 that supplies power to the current measurement unit 16G, and the current measurement unit 16G measures the current flowing from the cathode of the battery 34 to the emitter 11, thereby being able to separate radiation measurement from common mode noise that sneaks in from the power supply system, thereby further reducing the risk of noise contamination.

[0093] The conductor 21G is not essential.

[0094] Example 9 A self-powered radiation detector according to a ninth embodiment of the present invention will be described with reference to Fig. 9. Fig. 9 is a diagram showing a schematic configuration of the self-powered radiation detector according to the ninth embodiment.

[0095] The self-powered radiation detector 1H of this embodiment shown in Figure 9 is insulated from earth 61 and is configured with a data recording device 41 that records the measurement results of the current measuring unit 16H, and is a compact device configured to be mounted on equipment such as drones.

[0096] In FIG. 9, in order to make the self-powered radiation detector 1H more compact, the collector 12 and the housing frame 17H ​​are physically connected, and no conductor is provided between them and the current measuring unit 16H; however, the collector 12 and the housing frame 17H ​​may not be physically connected, and a conductor equivalent to the conductor 21B or the like may be provided.

[0097] The data recording device 41 receives and records the current value information from the current measuring unit 16H via the data communication wiring 33. An example of the data recording device 41 here is a data logger.

[0098] The power supply to the current measuring unit 16H and the data recording device 41 is provided by a battery 34.

[0099] The current measuring unit 16H measures the current flowing from the cathode of the battery 34 to the emitter 11.

[0100] The other configurations and operations are substantially the same as those of the self-powered radiation detector 1 of the first embodiment described above, and the details are omitted here.

[0101] The self-powered radiation detector 1H of Example 9 of the present invention also provides effects similar to those of the self-powered radiation detector 1 of Example 1 described above, and since the radiation measurement system can be configured wirelessly up to data collection, restrictions on operation when mounted on a drone or the like can be relaxed, making it easier to measure radiation levels in difficult-to-access locations.

[0102] Example 10 A self-powered radiation detector according to a tenth embodiment of the present invention will be described with reference to Fig. 10. Fig. 10 is a diagram showing a schematic configuration of the self-powered radiation detector according to the tenth embodiment.

[0103] The self-powered radiation detector 1I of this embodiment shown in FIG. 10 is configured such that the electron supply unit 18I and the ground 61 are periodically connected by a switch mechanism 51.

[0104] Since the number of electrons that can be supplied from the electron supply unit 18I is limited even if the electron supply unit 18I is a lump of metal, it is desirable to also provide a configuration for supplying electrons to the electron supply unit 18I in order to prevent electron depletion in areas with very high doses or when operating for very long periods of time.

[0105] Therefore, in the self-powered radiation detector 1I shown in FIG. 10, a contact conductor 52 is drawn out so as to contact the surrounding metal around the self-powered radiation detector 1I or the earth 61, and the detector is further provided with a switch mechanism 51 electrically connected to the electron supply unit 18I.

[0106] This switch mechanism 51 allows the electron supply unit 18I to be switched between conductive and insulated with respect to the earth 61 by the switch mechanism 51, and periodically connects to the earth 61 as a means for intermittently supplying electrons to the electron supply unit 18I. The switching between conductive and insulated may be automatic by a control board or the like, or may be manual by a user of the self-powered radiation detector 1I, and is not particularly limited.

[0107] Instead of or in addition to the earth 61, a switchable connection / insulation with a peripheral metal 72 may be used as will be described in an eleventh embodiment below.

[0108] If the earth 61 and the self-powered radiation detector 1I are always connected, there is a risk of interference noise from the power supply system, such as common mode noise. However, by using a configuration as shown in Figure 10, the earth 61 and the self-powered radiation detector 1I can be separated during radiation measurement.

[0109] The current measuring unit 16I measures the current flowing between the collector 12 and the emitter 11.

[0110] Regarding the timing for connecting the earth 61 and the self-powered radiation detector 1I by the switch mechanism 51, it is expected that the switch mechanism 51 will be connected periodically at regular intervals, or that the switch mechanism 51 will be connected to the earth 61 while measurement is stopped.

[0111] The other configurations and operations are substantially the same as those of the self-powered radiation detector 1 of the first embodiment described above, and the details are omitted here.

[0112] The self-powered radiation detector 1I of the tenth embodiment of the present invention also provides substantially the same effects as those of the self-powered radiation detector 1 of the first embodiment described above.

[0113] In addition, a contact conductor 52 is drawn out so as to contact the surrounding metal or earth 61 around the self-powered radiation detector 1I, and the detector is further provided with a switch mechanism 51 electrically connected to the electron supply unit 18I.The electron supply unit 118I can be switched between conductive and insulated with the surrounding metal or earth 61 by the switch mechanism 51, so that the amount of electrons supplied from the electron supply unit 18I, which is the electron supply source, can be made virtually infinite, and there is no risk of interference noise from the power supply system, such as common mode noise.

[0114] In this embodiment, the conductor 21I is not essential. Alternatively, the housing frame 17I may be insulated from the electron replenishment unit 18I, and the electron replenishment unit 18I and the current measurement unit 16I may be connected by a conductor.

[0115] Example 11 An eleventh embodiment of the self-powered radiation detector of the present invention will be described with reference to Fig. 11. Fig. 11 is a diagram showing a schematic configuration of the self-powered radiation detector of the eleventh embodiment.

[0116] The self-powered radiation detector 1J of this embodiment shown in Figure 11 is configured to be suitable for operation in an environment where metal is present in the vicinity, and instead of being equipped with electron supply units 18, 18A, 18B, 18C, 18D, 18F, 18I like the self-powered radiation detectors 1, 1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H, 1I of embodiments 1 to 10, it is configured to utilize surrounding metal as an electron supply unit.

[0117] As shown in FIG. 11, the self-powered radiation detector 1J includes a metal emitter 11, a collector 12, insulating materials 13 and 14, a current measuring unit 16J, a conductor 15 electrically connecting the emitter 11 and the current measuring unit 16J, a housing frame 17J that houses the current measuring unit 16J, a conductor 21, and a switch mechanism 51J from which a contact conductor 71 is drawn out so as to come into contact with surrounding metal 72 around the self-powered radiation detector 1J.

[0118] Of these components, at least the emitter 11, the collector 12, the current measuring unit 16J, the conductor 15, the housing frame 17J, and the switch mechanism 51J are insulated from the earth 61.

[0119] The surrounding metal 72 is, for example, a metal scaffolding or the like that exists around the self-powered radiation detector 1J, and is referred to as the surrounding metal 72 here.

[0120] The contact conductor 71 is preferably mounted on a moving mechanism, and is configured so that by changing its orientation, the contact conductor 71 comes into contact with the surrounding metal 72. When the contact conductor 71 and the surrounding metal 72 are in contact and the current measuring unit 16J and the contact conductor 71 are brought into a conductive state by the switch mechanism 51J, the surrounding metal 72 functions as an electron supply unit.

[0121] The connection between the switch mechanism 51J and the current measurement unit 16J may be a direct connection to the circuit within the current measurement unit 16J, or may be a configuration in which the housing frame 17 is connected to the circuit within the current measurement unit 16J via the housing frame 17.

[0122] Then, the current measurement unit 16J measures the current flowing between the peripheral metal 72 and the emitter 11 when the peripheral metal 72 and the current measurement unit 16J are connected by the switch mechanism 51J.

[0123] With this configuration, when gamma rays are irradiated onto the self-powered radiation detector 1J, an interaction occurs between the gamma rays and the emitter 11, causing electrons to be ejected from the emitter 11. As the electrons are ejected, the number of electrons in the emitter 11 decreases, and electrons move from the surrounding metal 72 to compensate for these electrons, generating a current. This current is measured by the current measurement unit 16J. Because the number of electrons generated is proportional to the amount of radiation irradiated, the amount of radiation irradiated onto the self-powered radiation detector 1J can be measured from the measured current value.

[0124] The other configurations and operations are substantially the same as those of the self-powered radiation detector 1 of the first embodiment described above, and the details are omitted here.

[0125] The self-powered radiation detector 1J of the eleventh embodiment of the present invention also provides substantially the same effects as the self-powered radiation detector 1 of the first embodiment described above.

[0126] In this embodiment, the conductive wire 21J is not essential.

[0127] <Other> It should be noted that the present invention is not limited to the above-described embodiment, and includes various modifications. The above-described embodiment has been described in detail to clearly explain the present invention, and the present invention is not necessarily limited to an embodiment having all of the described configurations.

[0128] It is also possible to replace part of the configuration of one embodiment with the configuration of another embodiment, or to add the configuration of another embodiment to the configuration of one embodiment, or to add, delete, or replace part of the configuration of each embodiment with the configuration of another embodiment. [Explanation of symbols]

[0129] 1, 1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H, 1I, 1J: Self-powered radiation detector 11: Emitter 12, 12B, 12C, 12D, 12E: Collector 13, 14, 20, 22: Insulation material 15: Conductor (first conductor) 16, 16A, 16B, 16C, 16D, 16E, 16F, 16G, 16I, 16H, 16J: Current measurement section 17, 17A, 17B, 17C, 17D, 17E, 17F, 17G, 17H, 17I, 17J: Housing frame 18,18A,18B,18C,18D,18F,18I:Electronic supply section 19: Conductor 21B, 21C, 21E, 21F, 21G, 21I, 21J: Conductor (second conductor) 31: Isolated data output section 32: Data receiving unit 33: Data communication wiring 34: Battery (electronic supply unit) 35,36:Power supply wire 41: Data recording device (data recording unit) 51, 51J: Switch mechanism 52,71: Contact conductor 61: Earth 72: Surrounding metal (metal part)

Claims

1. A metallic emitter; A collector and a current measuring unit; a first conductor electrically connecting the emitter and the current measuring unit; a housing frame that houses the current measuring unit; an electron supply unit that supplies electrons to the current measurement unit, the emitter, the collector, the current measuring unit, the first conductor, the housing frame, and the electron supply unit are insulated from earth; The current measuring unit measures the current flowing between the electron supply unit and the emitter. Self-powered radiation detector.

2. 2. The self-powered radiation detector of claim 1, the housing frame is made of metal, the housing frame and the electronic supply unit are electrically connected to each other; The current measuring unit measures the current flowing between the electron supply unit and the emitter via the housing frame. Self-powered radiation detector.

3. 2. The self-powered radiation detector of claim 1, a second conductor insulated from the earth and connecting the collector and the current measuring unit; the collector and the electron supply unit are electrically connected to each other, The current measuring unit measures the current flowing between the collector and the emitter. Self-powered radiation detector.

4. 4. The self-powered radiation detector of claim 3, the housing frame is made of metal, The housing frame and the electronic supply unit are integrated together. Self-powered radiation detector.

5. 2. The self-powered radiation detector of claim 1, The device further includes a data recording unit that is insulated from the earth and records the measurement results of the current measuring unit. Self-powered radiation detector.

6. 2. The self-powered radiation detector of claim 1, the electronic supply unit is a power source that supplies power to the current measurement unit, The current measuring unit measures the current flowing from the cathode of the power supply to the emitter. Self-powered radiation detector.

7. A metallic emitter; A collector and a current measuring unit; a first conductor electrically connecting the emitter and the current measuring unit; a housing frame that houses the current measuring unit; a switch mechanism having a contact conductor drawn out so as to contact a metal portion around the self-powered radiation detector; the emitter, the collector, the current measuring unit, the first conductor, the housing frame, and the switch mechanism are insulated from ground; The current measuring unit measures the current flowing between the metal part and the emitter when the metal part and the current measuring unit are connected by the switch mechanism. Self-powered radiation detector.

8. 8. The self-powered radiation detector according to claim 1, wherein The second conductor is insulated from the earth and connects the collector and the current measuring unit. Self-powered radiation detector.

9. 8. A self-powered radiation detector according to claim 1, and further comprising an isolated data output section insulated from the ground, The data output unit transfers the measured current value as data. Self-powered radiation detector.

10. 7. A self-powered radiation detector according to claim 1, a switch mechanism having a contact lead drawn out so as to contact a metal part around the self-powered radiation detector or the earth and electrically connected to the electron supply unit; The electron supply unit can be switched between electrical continuity and insulation with the metal unit or the earth by the switch mechanism. Self-powered radiation detector.

11. 7. A self-powered radiation detector according to claim 1, The electron supply unit is a metal block. Self-powered radiation detector.

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