Portable neutron personal dosimeter

Abstract

The portable neutron personal dosimeter disclosed by the embodiment of the invention comprises a silicon semiconductor detector unit used for detecting neutron radiation and generating a corresponding electric signal; the pre-amplification circuit unit is connected with the silicon semiconductor detector unit and is used for processing the detected neutron radiation electric signals and converting the neutron radiation electric signals into pulse signals; the information processing unit is configured to be connected with the pre-amplification circuit unit and is used for processing the pulse signal and outputting neutron dose information; the power supply circuit unit is used for respectively providing proper voltage for the silicon semiconductor detector unit, the pre-amplification circuit unit and the information processing unit; the display screen unit is connected with the information processing unit and is used for displaying the neutron dose information; and the alarm unit is connected with the information processing unit and is used for outputting an alarm signal. The portable neutron personal dosimeter device is simple in structure and light and convenient to use, can accurately detect neutron radiation, can well protect individuals, and has a good application prospect in the field of neutron radiation detection.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of radiation detection, and particularly relates to a portable neutron personal dosimeter. BACKGROUND

[0002] Neutrons are electrically neutral particles, which have radiation hazards to many materials and biological tissues. Therefore, monitoring and measuring neutron radiation is crucial for radiation protection and safety. A neutron dose rate measuring instrument is a device for measuring neutron radiation dose rate. A portable neutron personal dosimeter can detect neutron radiation, provide real-time personal radiation dose equivalent rate and dose equivalent information for nuclear personnel, and provide early warning for possible radiation exceeding events to protect nuclear personnel from excessive nuclear radiation. However, the current portable neutron dosimeter has low accuracy in detecting neutron radiation, cannot well predict the radiation exposure of personnel, and cannot achieve good personal protection. SUMMARY

[0003] Therefore, some embodiments disclose a portable neutron personal dosimeter, which comprises:

[0004] A silicon semiconductor detector unit is used to detect neutron radiation and generate corresponding electrical signals.

[0005] A preamplifier circuit unit is connected to the silicon semiconductor detector unit and is used to process the detected neutron radiation electrical signals and convert them into pulse signals.

[0006] An information processing unit is connected to the preamplifier circuit unit and is used to process the pulse signals and output neutron dose information.

[0007] A power supply circuit unit is used to provide appropriate voltages to the silicon semiconductor detector unit, the preamplifier circuit unit, and the information processing unit, respectively.

[0008] A display screen unit is connected to the information processing unit and is used to display the neutron dose information.

[0009] An alarm unit is connected to the information processing unit and is used to output an alarm signal.

[0010] Some embodiments disclose a portable neutron personal dosimeter, wherein the preamplifier circuit unit comprises:

[0011] A preamplifier module is used to amplify the neutron radiation electrical signals.

[0012] A shaping filter module is used to filter the amplified neutron radiation electrical signals.

[0013] A voltage amplifier module is used to amplify the filtered radiation electrical signals.

[0014] The discrimination comparator module is used to convert the amplified neutron radiation electrical signal into a stable radiation signal.

[0015] Some embodiments of the portable neutron personal dosimeter disclosed include a preamplifier module comprising:

[0016] Operational amplifier U6;

[0017] The fifth and sixth interfaces of the operational amplifier U6 are connected, and further connected to the power supply filter bead FB1. The power supply filter bead FB1 is further connected to the VCC_3V3A power supply.

[0018] The fifth and sixth interface terminals of the operational amplifier U6 are further connected with parallel power supply filter capacitors C24, C25, and C26, which are further grounded.

[0019] The third interface terminal of operational amplifier U6 is connected in sequence to the source of electrostatic discharge protection diode D5, feedback resistor R28, and field-effect transistor Q7; the other end of feedback resistor R28 is connected to VCC_3V3A power supply; electrostatic discharge protection diode D5 is further grounded; the drain of field-effect transistor Q7 is connected to parallel resistor R43 and capacitor C44, and the other end of parallel resistor R43 and capacitor C44 is grounded.

[0020] The fourth interface of operational amplifier U6 is connected to a parallel compensation filter capacitor C39 and a compensation filter resistor R37. The parallel compensation filter capacitor C39 and the compensation filter resistor R37 are further connected to the second interface of operational amplifier U6 and are grounded. The fourth interface of operational amplifier U6 is also connected to a feedback resistor R29. The other end of the feedback resistor R29 is connected to the fifth and sixth interface of operational amplifier U6.

[0021] The gate of the field-effect transistor Q7 is connected to a parallel phase compensation resistor R26 and a phase compensation capacitor C30, which are further connected to the first interface terminal of the operational amplifier U6.

[0022] The gate of the field-effect transistor Q7 is further connected to a DC blocking capacitor C35. C35 is further connected in sequence to a voltage divider and current-limiting resistor R31, a voltage divider and current-limiting resistor R27, and a VCCA_10V power supply. A coaxial interface J2 is connected between C35 and R31, and J2 is grounded. An input filter capacitor C29 is connected between R31 and R27, and C29 is further grounded. An input filter capacitor C27 is connected between R27 and the VCCA_10V power supply, and C27 is further grounded.

[0023] Some embodiments of the portable neutron personal dosimeter disclosed include a shaping filter module comprising:

[0024] Operational amplifier U7A;

[0025] The eighth interface of the operational amplifier U7A is connected to a power supply filter bead FB2, which is further connected to a VCC_3V3A power supply. The eighth interface of the operational amplifier U7A is also connected to parallel power supply filter capacitors C28 and C31, which are further grounded.

[0026] The third interface terminal of operational amplifier U7A is connected in sequence to phase compensation / filter capacitor C38, voltage divider current limiting resistor R34, high-frequency filter capacitor C37, voltage divider current limiting surge resistor R33, filter capacitor C33, and filter resistor R32; phase compensation / filter capacitor C38 is further grounded; resistor R40 and capacitor C36 are connected between voltage divider current limiting resistor R33 and filter capacitor C33, and resistor R40 is further grounded;

[0027] The second interface terminal of the operational amplifier U7A is connected to feedback resistors R44 and R47; feedback resistor R47 is further grounded, feedback resistor R44 is further connected to feedback resistor R45, and feedback resistor R45 is further connected to the first interface terminal of the operational amplifier U7A; high-frequency filter capacitor C37 is further connected between feedback resistor R44 and feedback resistor R45.

[0028] The first interface terminal of the operational amplifier U7A is further connected to capacitor C34, which is further connected to a parallel phase compensation capacitor C42 and a phase compensation resistor R41. The other end of the parallel phase compensation capacitor C42 and the phase compensation resistor R41 is grounded.

[0029] Some embodiments of the portable neutron personal dosimeter disclosed include a voltage amplifier module comprising:

[0030] The fifth interface end of the operational amplifier U7B is configured to be connected with a front-stage circuit;

[0031] The fifth interface end of the operational amplifier U7B is configured to be connected with a front-stage circuit;

[0032] The sixth interface end of the operational amplifier U7B is configured to be connected with the parallel feedback resistor R39 and the phase compensation capacitor C43, and is further configured to be connected with the input current-limiting / bias resistor R46 and the input filter capacitor C45 in sequence, the input filter capacitor C45 is further configured to be grounded, and the parallel feedback resistor R39 and the phase compensation capacitor C43 are further configured to be connected with the seventh interface end of the operational amplifier U7B; the seventh interface end of the operational amplifier U7B is further configured to be connected with the output current-limiting resistor R35.

[0033] The discrimination comparator module of the portable neutron personal dosimeter disclosed by some embodiments comprises:

[0034] The operational amplifier U8;

[0035] The third interface end of the operational amplifier U8 is configured to be connected with the parallel filter resistor R38 and the filter capacitor C40; the parallel filter resistor R38 and the filter capacitor C40 are further configured to be connected with the second interface end of the operational amplifier U8 and are configured to be grounded;

[0036] The fourth interface end of the operational amplifier U8 is configured to be connected with the amplification resistor R42, and the amplification resistor R42 is further configured to be connected with the second interface end of the operational amplifier U8;

[0037] The first interface end of the operational amplifier U8 is configured to be connected with the filter shaping resistor R36, the filter shaping resistor R36 is configured to be connected with the filter shaping capacitor C41, and the filter shaping capacitor C41 is further configured to be connected with the second interface end of the operational amplifier; a rear-stage circuit is configured between the filter shaping resistor R36 and the filter shaping capacitor C41, and a shaped stable radiation signal is transmitted to the rear-stage circuit;

[0038] The fifth interface end of the operational amplifier U8 is configured to be connected with the amplification resistor R30 and the power filter capacitor C32, the power filter capacitor C32 is further configured to be grounded, and the amplification resistor R30 is further configured to be connected with the fourth interface end of the operational amplifier U8; the amplification resistor R30 and the power filter capacitor C32 are configured to be connected with the VCC_3V3A power supply.

[0039] The power supply circuit unit of the portable neutron personal dosimeter disclosed by some embodiments comprises a step-down circuit module, a step-up circuit module, a storage circuit module, a switch control circuit module, a key circuit module, and a display screen interface circuit module.

[0040] Further, the step-down circuit module of the portable neutron personal dosimeter disclosed by some embodiments comprises:

[0041] DC-DC converter U1;

[0042] The first interface end and the fourth interface end of the DC-DC converter U1 are connected, and the second interface end of the DC-DC converter U1 is grounded; the input filter capacitor C1 is connected in parallel between the second interface end and the first interface end of the DC-DC converter U1; the input filter capacitor and the first interface end and the fourth interface end are further connected with the input voltage end VCC_BAT;

[0043] The third interface end of the DC-DC converter U1 is connected with the inductor L1, and the inductor L1 is further connected with the feedback and output adjusting resistor R4, the output filter capacitor C2, C3, C4 in sequence, and further connected with the output voltage end VCC_3V3;

[0044] The feedback and output adjusting resistor R7 is connected between the fifth interface end and the second interface end of the DC-DC converter U1, and the fifth interface end is further connected with the other end of the feedback and output adjusting resistor R4 and the other end of the output filter capacitor C2; the other ends of the output filter capacitors C3 and C4 are grounded;

[0045] The two ends of the output filter capacitor C4 are further connected with the two ends of the protection diode D1 respectively.

[0046] Some embodiments of the portable neutron personal dosimeter disclosed, the boost circuit module comprises:

[0047] Boost converter U3;

[0048] The inductor L2 is connected between the VIN interface end and the SW interface end of the boost converter U3; the EN interface end of the boost converter U3 is connected with one end of the resistor R11, the inductor L2 and the other end of the resistor R11 are connected, and further connected with the input voltage end VCC_BAT;

[0049] The input filter capacitor C6 is connected between the GND end of the boost converter U3 and the input voltage end VCC_BAT, and the input filter capacitor C6 is grounded with the GND end of the boost converter U3;

[0050] The SW interface end of the boost converter U3 is further connected with the diode D2, the output filter capacitors C9 and C10 in sequence; the FB interface end of the boost converter U3 is connected with the output adjusting resistors R12 and R15, the other end of the output adjusting resistor R12 is connected between the diode D2 and the output filter capacitor C9, the other end of the output adjusting resistor R15 is grounded GND, and is further connected with the other end of the output filter capacitors C9 and C10; the output end of the diode D2 outputs the boosted DC voltage VCC_12V;

[0051] voltage stabilizer U2;

[0052] The first interface end and the third interface end of the voltage stabilizer U2 are connected, and are further connected with the direct current voltage VCC_12V; the second interface end of the voltage stabilizer U2 is grounded; and the second interface end and the first interface end of the voltage stabilizer U2 are connected in parallel with the input filter capacitor C11.

[0053] The fourth interface end of the voltage stabilizer U2 is connected with the output adjusting resistor R13, R14 and R16; the fifth interface end of the voltage stabilizer U2 is sequentially connected with the other end of the output adjusting resistor R13, the output filter capacitor C7 and C8; the other end of the output adjusting resistor R16 is connected with the second interface end of the voltage stabilizer U2; the other end of the output adjusting resistor R14 is connected with the other end of the output filter capacitor C7, and the other end of the output filter capacitor C8 is connected with the other end of the output adjusting resistor R16; and the fifth interface end of the voltage stabilizer U2 finally outputs the direct current voltage VCC_10V after being reduced and stabilized.

[0054] Some embodiments of the portable neutron personal dosimeter disclosed, the storage circuit module comprises:

[0055] Erasable programmable read-only memory U4;

[0056] The first interface end, the second interface end, the third interface end and the fourth interface end of the erasable programmable read-only memory U4 are connected, and are grounded;

[0057] The eighth interface end of the erasable programmable read-only memory U4 is connected with the VCC_3V3 power supply;

[0058] The seventh interface end of the erasable programmable read-only memory U4 is grounded;

[0059] The sixth interface end of the erasable programmable read-only memory U4 is connected with the I2C_SCL of the system bus;

[0060] The fifth interface end of the erasable programmable read-only memory U4 is connected with the I2C_SDA of the system data line.

[0061] The portable neutron personal dosimeter disclosed by the embodiment of the application has simple device structure, is light to use, can accurately detect neutron radiation, can realize good protection of individuals, and has good application prospect in the field of neutron detection. BRIEF DESCRIPTION OF DRAWINGS

[0062] Figure 1 , the portable neutron personal dosimeter system composition schematic view;

[0063] Figure 2Fig. 1 is a schematic diagram of a pre-amplifier module;

[0064] Figure 3 Fig. 2 is a schematic diagram of a pre-amplifier module;

[0065] Figure 4 Fig. 3 is a schematic diagram of a shaping filter module;

[0066] Figure 5 Fig. 4 is a schematic diagram of an amplifying circuit module;

[0067] Figure 6 Fig. 5 is a schematic diagram of a discrimination comparator module;

[0068] Figure 7 Fig. 6 is a schematic diagram of a voltage down-conversion circuit module;

[0069] Figure 8 Fig. 7 is a schematic diagram of a voltage up-conversion circuit module;

[0070] Figure 9 Fig. 8 is a schematic diagram of a storage circuit module

[0071] Figure 10 Fig. 9 is a schematic diagram of a portable neutron personal dosimeter structure

[0072] Figure 11 Fig. 10 is a schematic diagram of a switch control circuit module;

[0073] Figure 12 Fig. 11 is a schematic diagram of a key circuit module.

[0074] Reference signs

[0075] 1 lower shell 2 upper shell

[0076] 3 indicator light 4 buzzer

[0077] 5 display screen 6 first key

[0078] 7 second key 8 battery cover DETAILED DESCRIPTION

[0079] The term "exemplary" used in this disclosure as in "exemplary embodiment" should not be construed as a preference or advantage over other embodiments. The performance index test in the embodiments of the present application is carried out by using the conventional test method in the art, unless otherwise specified. It should be understood that the terms described in the embodiments of the present application are only used to describe the specific embodiments, and are not used to limit the disclosure of the embodiments of the present application.

[0080] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which embodiments of the application belong. Methods and materials similar or equivalent to those described herein can be used in the practice of the embodiments of the application. The techniques and procedures described or referenced herein are exemplary and other equivalent techniques and procedures known to those of ordinary skill in the art can be used alternatively.

[0081] The terms "substantially" and "approximately" as used herein are used to describe small fluctuations. For example, they can mean less than or equal to ± 5%, such as less than or equal to ± 2%, such as less than or equal to ± 1%, such as less than or equal to ± 0.5%, such as less than or equal to ± 0.2%, such as less than or equal to ± 0.1%, such as less than or equal to ± 0.05%. Numerical data can be expressed or presented herein in a range format. Accordingly, this disclosure includes numerical values that are the same when rounded to the same significant digits as required by the medium of expression, i.e., the number of significant digits to be used in the presentation of the data. The use of "about" or "approximately" in connection with a range applies to both ends of the range. It will be further understood that the endpoints of the ranges are not significant and are intended to be merely illustrative of the extent of the range. It must be noted that all ranges given throughout this specification will include the beginning and ending values of the range, and further will include any other value or point within the range. The term "about" when used before a numerical designation, including a range of values, indicates that the cap value or operating conditions can vary from the indicated value by as much as 1%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, or other such amount, as understood by those of ordinary skill in the art.

[0082] In this document, including in the claims, the conjunctions, such as "comprising", "including", "containing", "having", "involving", "holding", "carrying", and the like are to be understood as open-ended, i.e., as meaning "including but not limited to". Only the conjunctions "consisting of" and "consisting exclusively of" are closed conjunctions.

[0083] For the purposes of the present application, numerous specific details are set forth in the following description in order to provide a thorough understanding. Those skilled in the art will realize, however, that the application can be practiced without these specific details. In other instances, well-known methods, procedures, instruments, devices, and the like have not been described in detail since they would be well understood that the application is not to be limited in scope by the specific embodiments described herein, which are intended as illustrations of one or more aspects of the application. Any

[0084] The technical features disclosed by the embodiments of the present application can be combined arbitrarily without conflict, and the technical solutions obtained by the combination belong to the disclosure of the embodiments of the present application.

[0085] In some embodiments, as shown in FIG. 1, Figure 1 The portable neutron personal dosimeter comprises:

[0086] a silicon semiconductor detector unit for detecting neutron radiation and generating a corresponding electrical signal;

[0087] The preamplifier circuit unit is connected to the silicon semiconductor detector unit to process the detected neutron radiation electrical signal and convert it into a pulse signal;

[0088] The information processing unit is configured to be connected to the preamplifier circuit unit to process pulse signals and output neutron dose information;

[0089] The power supply circuit unit is used to provide appropriate voltages to the silicon semiconductor detector unit, the preamplifier circuit unit, and the information processing unit, respectively.

[0090] The display unit is connected to the information processing unit and is used to display neutron dose information;

[0091] The alarm unit is connected to the information processing unit and is used to output alarm signals.

[0092] Typically, neutrons enter a silicon semiconductor detector and undergo a nuclear reaction, producing charged particle pairs. These high-energy ionized particles enter the detector's sensitive region, generating electron-hole pairs (the number of which is proportional to the energy of the neutrons deposited in the sensitive region). The movement of electrons and holes under a reverse bias voltage causes changes in the induced charge on the two electrodes, which are ultimately collected in the form of electrical pulses to form the detector's response signal.

[0093] The silicon semiconductor detector unit detects neutrons and outputs electrical signals. These signals are amplified by the preamplifier circuit unit and converted into digital signals. The MCU in the information processing unit then counts these signals. The battery circuit unit supplies power to other functional units. The display unit shows the measurement results. The alarm unit provides alarm information. The buttons provide the operation interface. The LED indicator shows the working status and provides a light alarm. The buzzer provides an audible alarm.

[0094] In some embodiments, such as Figure 2 As shown, the preamplifier circuit unit includes: a preamplifier module for amplifying the neutron radiation signal; a shaping filter module for filtering the amplified neutron radiation signal; a voltage amplifier module for amplifying the filtered radiation signal; and a discrimination comparator module for converting the amplified neutron radiation signal into a stable radiation signal. Typically, the preamplifier circuit unit processes electrical pulse signals to facilitate the radiation particle counting function. It includes a detector interface and pre-acquisition stage, a preamplifier, a filter, a voltage amplifier, a discrimination comparator, and an output and interface stage. It receives weak signals from the detector, amplifies them, filters them, discriminates them, shapes them, and outputs them, ultimately converting them into pulses recognizable by a digital system.

[0095] Some embodiments disclose portable neutron personal dosimeters, such as Figure 3As shown, the preamplifier module comprises: an operational amplifier U6; the fifth interface end and the sixth interface end of the operational amplifier U6 are connected, and are further connected with the power filter magnetic bead FB1, and the power filter magnetic bead FB1 is further connected with the VCC_3V3A power supply; the fifth interface end and the sixth interface end of the operational amplifier U6 are further connected with the parallelly connected power filter capacitors C24, C25 and C26, and the parallelly connected power filter capacitors C24, C25 and C26 are further grounded; the third interface end of the operational amplifier U6 is connected with the static protection diode D5, the feedback resistor R28 and the source electrode of the field effect transistor Q7 in sequence; the other end of the feedback resistor R28 is connected with the power supply VCC_3V3A; the static protection diode D5 is further grounded; the drain electrode of the field effect transistor Q7 is connected with the parallelly connected resistor R43 and capacitor C44, and the other end of the parallelly connected resistor R43 and capacitor C44 is grounded; the fourth interface end of the operational amplifier U6 is connected with the parallelly connected compensation filter capacitor C39 and compensation filter resistor R37, and the parallelly connected compensation filter capacitor C39 and compensation filter resistor R37 are further connected with the second interface end of the operational amplifier U6 and grounded; the fourth interface end of the operational amplifier U6 is further connected with the feedback resistor R29, and the other end of the feedback resistor R29 is connected with the fifth interface end and the sixth interface end of the operational amplifier U6; the gate electrode of the field effect transistor Q7 is connected with the parallelly connected phase compensation resistor R26 and phase compensation capacitor C30, and the parallelly connected phase compensation resistor R26 and phase compensation capacitor C30 are further connected with the first interface end of the operational amplifier U6, and the first interface end of the operational amplifier U6 is further connected with the input end of the subsequent circuit; the gate electrode of the field effect transistor Q7 is further connected with the direct current blocking coupling capacitor C35, and the direct current blocking coupling capacitor C35 is further connected with the voltage dividing current limiting resistor R31, voltage dividing current limiting resistor R27 and VCCA_10V power supply in sequence; the coaxial interface J2 is connected between the direct current blocking coupling capacitor C35 and the voltage dividing current limiting resistor R31, and the coaxial interface J2 is grounded; the input filter capacitor C29 is connected between the voltage dividing current limiting resistor R31 and the voltage dividing current limiting resistor R27, and the input filter capacitor C29 is further grounded; the input filter capacitor C27 is connected between the voltage dividing current limiting resistor R27 and the VCCA_10V power supply, and the input filter capacitor C27 is further grounded.

[0096] Generally, in the preamplifier module circuit:

[0097] The preamplifier module is based on the charge sensitivity amplification circuit of the operational amplifier ADA4807 chip, and adopts a complete conditioning circuit of "filtering → protection → precise amplification → power purification" for the weak high-frequency signal collected by the detector. The operational amplifier ADA4807 is used to realize high-precision amplification, so as to provide a clean and appropriate amplitude signal for the subsequent processing, and solve the problems of weak signal interference and difficult amplification. The ADA4807 used by the operational amplifier U6 is a high-speed, low-noise and high-precision operational amplifier, which has high bandwidth and low offset voltage, and can effectively amplify weak signals while maintaining precision.

[0098] The J2 coaxial interface is a COAXIAL socket, which receives external weak signals. The coaxial structure has strong anti-interference performance and is suitable for transmitting high-frequency and small-amplitude signals. The input filter capacitors C27 and C29 (10 nF) cooperate with the voltage dividing and current limiting resistors R27 and R31 to filter high-frequency noise in the input signal and form a simple RC filter to preliminarily purify the signal. The voltage dividing and current limiting resistors R27 (100 KΩ) and R31 (100 MΩ) adjust the amplitude of the input signal, and the high resistance characteristic of R31 can reduce the load impact on the weak input signal.

[0099] The blocking direct current coupling capacitor C35 (1 nF) blocks the direct current component in the input signal and only allows alternating current signals to pass through, so as to ensure that the subsequent amplifier works at a suitable direct current level. The BF862 junction field effect transistor JFET Q7 provides input protection and impedance matching. The high input impedance characteristic of the JFET can further reduce the load on the previous stage signal, and can also provide a certain clamping protection when the voltage is too high. The static protection diode D5 can use PESD7V3L1UG to realize ESD protection, prevent static and surge from damaging the subsequent amplifier through the input port, and clamp the overvoltage within a safe range.

[0100] The feedback resistors R28 (1 KΩ) and R29 (10 KΩ) and the operational amplifier U6 form a same-phase proportional amplification circuit to amplify the weak input signal to a suitable amplitude. The compensation filter capacitor C39 (0.1 μF) and the compensation filter resistor R37 (20 KΩ) improve the frequency response (such as phase compensation) of the operational amplifier U6, avoid self-oscillation, and filter high-frequency noise after amplification. The phase compensation capacitor C30 (1 pF) is connected in parallel in the feedback loop to further optimize the phase margin of the amplifier and ensure the stability of the high-frequency signal amplification.

[0101] The VCC_3V3A power supply provides 3.3V to the operational amplifier U6 and its peripheral circuits, and must ensure low noise and high stability. The power supply filter bead FB1 (CBM160808U121T ferrite bead) suppresses high-frequency noise on the power lines, ensuring a clean operating power supply for the op-amp. Power supply filter capacitors C24 (1nF), C25 (0.1μF), and C26 (10μF) provide all-around filtering from high to low frequencies. The 1nF capacitor C24 filters out high-frequency noise, the 0.1μF capacitor C25 filters out intermediate frequency ripple, and the 10μF capacitor C26 stabilizes the power supply voltage to cope with dynamic current changes in the op-amp.

[0102] The TP9 test point is the output signal test point. It can be used to measure the amplitude and frequency of the amplified signal with an oscilloscope, and is used to debug and verify the circuit performance.

[0103] In some embodiments, such as Figure 4 As shown, the shaping filter module includes: an operational amplifier U7A; a power filter bead FB2 is connected to the eighth interface of the operational amplifier U7A, and the power filter bead FB2 is further connected to a VCC_3V3A power supply; the eighth interface of the operational amplifier U7A is also connected to parallel power filter capacitors C28 and C31, and the parallel power filter capacitors C28 and C31 are further grounded to AGND; the third interface of the operational amplifier U7A is sequentially connected to a phase compensation / filter capacitor C38, a voltage divider current limiting resistor R34, a high-frequency filter capacitor C37, a voltage divider current limiting surge resistor R33, a filter capacitor C33, and a filter resistor R32; the phase compensation / filter capacitor C38 is further grounded; a resistor R40 and a capacitor C36 are connected between the voltage divider current limiting resistor R33 and the filter capacitor C33, and the resistor R40 is further grounded; the capacitor C36 is further connected to the output of the preceding circuit. Next, the filter resistor R32 is further connected to the output of the preamplifier circuit, for example, to the first interface terminal of the operational amplifier U6 in the preamplifier module; the second interface terminal of the operational amplifier U7A is connected to feedback resistors R44 and R47; the feedback resistor R47 is further grounded, the feedback resistor R44 is further connected to the feedback resistor R45, and the feedback resistor R45 is further connected to the first interface terminal of the operational amplifier U7A; the high-frequency filter capacitor C37 is further connected between the feedback resistors R44 and R45; the first interface terminal of the operational amplifier U7A is further connected to the capacitor C34, the capacitor C34 is further connected to the parallel phase compensation capacitor C42 and the phase compensation resistor R41, and the other end of the parallel phase compensation capacitor C42 and the phase compensation resistor R41 is grounded to AGND; the pin leading out from the capacitor C34 is the amplified signal output terminal, which can be connected to the subsequent circuit.

[0104] Generally, the shaping filter module is mainly used for filtering, amplifying and noise suppression of the input signal, and is mainly used for precise processing scenes of weak signals. For the complete conditioning circuit of "filtering → precise amplification → power purification" of weak signals, the operational amplifier U7A is used to realize low-noise and high-precision amplification, and to provide a clean and appropriate amplitude signal for the subsequent processing circuit. Among them, the operational amplifier U7A can use ADA4505-2, which is a low-noise, high-precision, rail-to-rail output operational amplifier, with low offset voltage and high common-mode rejection ratio, suitable for weak signal amplification and high-precision signal conditioning, to ensure that the amplified signal is not distorted and has low noise.

[0105] In the shaping filter module, the filter resistor R32 (500Ω) and the filter capacitor C33 (1nF) form an RC filter network to filter out high-frequency noise in the input signal, and preliminarily purify the signal, while forming a simple signal attenuation / impedance matching. The voltage dividing current limiting resistors R33 (3KΩ) and R34 (38KΩ) further adjust the input signal amplitude, adapt to the input range of the operational amplifier ADA4505-2, and avoid overload; at the same time, the high-precision resistor ensures the stability of the voltage division ratio and does not introduce additional errors; the high-frequency filter capacitor C37 (220pF) cooperates with the voltage dividing current limiting resistor R34 to strengthen the high-frequency noise filtering, making the signal input to the operational amplifier more pure;

[0106] The feedback resistors R47 (100KΩ), R44 (20KΩ), and R45 (336R) form an inverting proportional amplification circuit with the operational amplifier ADA4505-2; usually combined with specific feedback resistor value calculation, in order to amplify the weak input signal to an appropriate amplitude (such as from mV level to V level); the phase compensation / filtering capacitor C42 (1nF) is connected in parallel in the feedback loop to optimize the phase margin of the operational amplifier, avoid high-frequency self-oscillation, and filter out high-frequency noise after amplification, ensuring signal stability;

[0107] The power supply VCC_3V3A provides 3.3V power supply for the operational amplifier U8 and the surrounding circuit, ensuring low noise and high stability; the power filter bead FB2 (CBM160808U121T ferrite bead) suppresses high-frequency noise on the power line, ensuring that the operational amplifier power supply is clean and avoiding noise coupling to the signal path; the power filter capacitors C28 (0.1μF) and C31 (0.1μF) filter out medium and high-frequency noise in the power supply, stabilize the power supply voltage, cope with the dynamic current change of the operational amplifier, and ensure the amplification accuracy.

[0108] In some embodiments, as shown in FIG. 1A, the voltage amplifier module includes: Figure 5

[0109] an operational amplifier U7B;

[0110] ​The fifth interface end of the operational amplifier U7B is provided for connecting the front-stage circuit; for example, connecting with the pin led out by the capacitor C34 of the shaping filter module; the fifth interface end of the operational amplifier U7B can be provided with a detection point TP7;

[0111] The sixth interface end of the operational amplifier U7B is provided with the parallel feedback resistor R39 and the phase compensation capacitor C43, and is further provided with the input current-limiting / biasing resistor R46 and the input filter capacitor C45 connected in sequence, the input filter capacitor C45 is further provided with the ground AGND, and the parallel feedback resistor R39 and the phase compensation capacitor C43 are further provided with the seventh interface end of the operational amplifier U7B; the seventh interface end of the operational amplifier U7B is further provided with the output current-limiting resistor R35; the seventh interface end of the operational amplifier U7B can be provided with a detection point TP8; the output current-limiting resistor R35 is provided for connecting the rear-stage circuit, for example, the filter capacitor C40 of the discrimination comparator module.

[0112] Generally, the voltage amplifier module is mainly used for low-noise and high-precision amplification of the input signal, and the stability is optimized through the compensation network. For the "filtering-precision amplification-stable output" circuit of the weak signal, the operational amplifier U7B is used to realize low-noise and high-precision amplification, and the stability is ensured through the compensation network, so as to provide a clean and appropriate amplitude signal for the rear-stage processing, and solve the problem that the weak signal is easy to be overwhelmed by noise and difficult to be accurately amplified; wherein the operational amplifier U7B can be selected as ADA4500-2ARZ, which is a low-noise and high-precision operational amplifier, and has wide bandwidth, low offset voltage and high common-mode rejection ratio (CMRR), and is used for weak signal amplification and high-precision signal processing, so as to ensure that the amplified signal is small in distortion and low in noise;

[0113] The feedback resistor R39 (10KΩ) and the ADA4500-2ARZ constitute a non-inverting proportional amplification circuit, and through the circuit design, the input weak signal can be amplified by 11 times. The phase compensation capacitor C43 (10pF) is connected in parallel between the feedback resistor R39, which optimizes the phase margin of the operational amplifier, avoids self-oscillation when amplifying high-frequency signals, and ensures stable operation of the circuit; the input current-limiting / biasing resistor R46 (1KΩ) provides a direct current bias path for the non-inverting terminal of the operational amplifier U7B, while limiting the input current and protecting the input stage of the operational amplifier; in combination with the non-inverting amplification structure, the input resistor R46 is the input impedance of the amplification circuit. The input filter capacitor C45 (10μF) and the input current-limiting / biasing resistor R46 constitute an RC filter network, which filters out low-frequency noise in the input signal, so that the signal input to the operational amplifier is more pure;

[0114] The output current-limiting resistor R35 (120 Ω) limits the output current of the operational amplifier, protects the load in the rear stage, and can suppress high-frequency oscillation of the output end. TP7 can be used to detect the input signal of the non-inverting terminal of the operational amplifier, and TP8 can be used to detect the amplified output signal, which facilitates the measurement of signal amplitude, frequency, noise, etc. using an oscilloscope and a multimeter, and is used for debugging and verifying the performance of the circuit; AGND is the analog ground, which provides a low-noise reference potential and avoids digital noise coupling.

[0115] In some embodiments, as shown in FIG. 1, the discrimination comparator module includes: Figure 6

[0116] The third interface end of the operational amplifier U8 is provided with parallel filter resistor R38 and filter capacitor C40; the parallel filter resistor R38 and filter capacitor C40 are further connected to the second interface end of the operational amplifier U8 and grounded; the other end of the filter capacitor C40 is connected to the previous stage circuit, for example, the output current-limiting resistor R35 of the voltage amplifier module; the fourth interface end of the operational amplifier U8 is provided with an amplification resistor R42, which is further connected to the second interface end of the operational amplifier U8; the first interface end of the operational amplifier U8 is provided with a filter shaping resistor R36, which is connected to a filter shaping capacitor C41, which is further connected to the second interface end of the operational amplifier; the filter shaping resistor R36 and the filter shaping capacitor C41 are connected to the next stage circuit, which transmits the shaped stable radiation signal to the next stage circuit; the fifth interface end of the operational amplifier U8 is provided with an amplification resistor R30 and a power filter capacitor C32, which is further grounded, and the amplification resistor R30 is further connected to the fourth interface end of the operational amplifier U8; the amplification resistor R30 and the power filter capacitor C32 are connected to the power supply VCC_3V3A.

[0117] ​Generally, based on the discrimination comparator module of the operational amplifier U8, the operational amplifier U8 can adopt TLV3201AIDBVR for amplification, filtering and shaping of weak radiation signals, and convert the small amplitude and easily disturbed signals output by the detector into stable signals that can be processed. The TLV3201 high bandwidth adapts to the narrow pulse characteristics of the radiation signal, ensuring that the signal is not distorted during amplification. The filter network composed of the filter capacitor C40, the power filter capacitor C32 and the filter shaping capacitor C41 realizes full-link noise suppression and avoids masking weak radiation signals. The filter resistor R38 matches the output impedance of the detector, reduces signal reflection and attenuation, and ensures signal integrity. Among them, the operational amplifier U8 selects a high-speed, low-noise, rail-to-rail output operational amplifier TLV3201AIDBVR as the core device, with high bandwidth (suitable for fast pulse signals) and low offset voltage, which can effectively amplify the weak pulse or current signal output by the radiation detector, while suppressing noise and ensuring signal quality; the filter resistor R38 and the filter capacitor C40 (33pF) form an RC filter network to filter high-frequency noise in the input signal, while achieving impedance matching to make the signal input to the operational amplifier purer; the amplification resistor R42 (9.3KΩ) and R30 (100KΩ) form a non-inverting proportional amplification circuit with the operational amplifier U8, which amplifies the weak signal output by the radiation detector to an appropriate amplitude, facilitating identification and processing by the subsequent circuit; the power filter capacitor C32 (0.1μF) filters high-frequency noise on the power line to ensure that the operational amplifier power supply is pure, avoiding noise coupling to the signal path and affecting the radiation signal amplification accuracy; the filter shaping resistor R36 (33Ω) and the filter shaping capacitor C41 (5.6nF) form an RC output filter / shaping network to further filter the amplified signal, while adjusting the signal rising / falling edge to make the output signal closer to an ideal pulse, facilitating accurate radiation event acquisition by the subsequent circuit; the TP6 test point is set before the subsequent circuit to measure the amplified signal waveform and verify the circuit performance; the CON connects the subsequent circuit to transmit the stable radiation signal after conditioning.

[0118] Some embodiments disclose a portable neutron personal dosimeter, and the power supply circuit unit includes a step-down circuit module, a step-up circuit module, a storage circuit module and a switch control circuit module.

[0119] In some embodiments, as shown in Figure 7 the step-down circuit module includes:

[0120] The first interface end (EN) and the fourth interface end (IN) of the DC-DC converter U1 are connected, and the second interface end (GND) of the DC-DC converter U1 is grounded; the input filter capacitor C1 is connected in parallel between the second interface end (GND) and the first interface end (EN) of the DC-DC converter U1; the input filter capacitor and the first interface end (EN) and the fourth interface end (IN) are further connected with the input voltage end VCC_BAT; the third interface end (LX) of the DC-DC converter U1 is connected with the inductor L1, and the inductor L1 is further connected with the feedback and output adjusting resistor R4, one end of the output filter capacitor C2, C3 and C4 in sequence, and further connected with the output voltage end VCC_3V 3; the feedback and output adjusting resistor R7 is connected between the fifth interface end (FB) and the second interface end (GND) of the DC-DC converter U1, and the fifth interface end (FB) is further connected with the other end of the feedback and output adjusting resistor R4 and the other end of the output filter capacitor C2; the other ends of the output filter capacitors C3 and C4 are grounded; the two ends of the output filter capacitor C4 are further connected with the two ends of the protection diode D1 respectively. The first interface end (EN) and the fourth interface end (IN) of the DC-DC converter U1 are connected, and the two ends of the protection diode D1 are respectively connected with the test points TP2 and TP4.

[0121] Generally, the step-down circuit module is a functional module based on the DC-DC step-down converter. A high-efficiency step-down topology is constructed by the DC-DC step-down converter, and a filter, a feedback, and a protection element are matched to realize conversion from an input voltage to a 3.3V stable output, meet the power supply demand of low noise and high reliability, and accurately and stably provide voltage for a clock circuit, a storage circuit, an MCU, and a communication circuit. The DC-DC step-down converter can adopt a SY8088 high-frequency synchronous step-down DC-DC converter, which has a built-in power MOSFET and supports efficient voltage conversion, and can stably output a target voltage in a wide input voltage range.

[0122] In the step-down circuit module, the input filter capacitor C1 is connected in parallel between the input voltage VCC_BAT and the ground, filters high-frequency noise in the input voltage, makes the voltage input to the chip purer, and helps to stabilize the chip operation and avoid voltage fluctuation interference in the conversion process; the inductor L1 (2.2μH) and the switching node are one of the key elements of the DC-DC step-down circuit. When the switching tube in the chip is turned on, the inductor stores energy; when the switching tube is turned off, the inductor releases energy through freewheeling, and cooperates with the internal circuit of the chip to realize voltage step-down conversion. The inductance value is selected to match the input and output voltages, load current and other parameters to ensure conversion efficiency and stability. The LX pin is the switching node of the DC-DC step-down converter chip, which is connected with the inductor and reflects the working state of the internal switching tube.

[0123] Feedback and output regulating resistors R4 (115K), R7 (25.5K) constitute a voltage dividing feedback network, connected to the feedback (FB pin) of the DC-DC step-down converter chip; the output voltage VCC_3V3 is fed back to the chip after voltage division, compared with the internal reference voltage, and the chip adjusts the on-time of the switch tube accordingly, thereby stabilizing the output 3.3V voltage;

[0124] Output filter capacitors C2 (33pF), C3 (22μF), C4 (0.1μF) are connected in parallel between the output VCC_3V3 and ground, belonging to the output filter capacitor group; small capacitance capacitors (such as C2, C4) mainly filter out high-frequency noise, have fast response speed, and suppress the ripple caused by switching frequency; large capacitance capacitors (such as C3) undertake bulk filtering, stabilize the DC component of the output voltage, and cope with voltage fluctuations when the load current changes, making the output smoother;

[0125] Protection diode D1 is an electrostatic discharge protection element, which can be CESD3V3D3 YU; it is connected in parallel between the output VCC_3V3 and ground; when the circuit encounters abnormal high voltage such as static electricity and surge, the protection diode D1 conducts to clamp the overvoltage within a safe range, protecting the subsequent load U circuit from damage; test points TP1, TP2, TP4 are used to measure the voltage and waveform of the corresponding nodes with an oscilloscope and a multimeter during debugging and maintenance, such as TP1 measuring the input voltage, TP2 measuring the output voltage, and TP4 measuring the ground or auxiliary detection, to quickly determine whether the circuit is working normally.

[0126] In some embodiments, as shown in FIG. 1, the boost circuit module includes: Figure 8

[0127] ​The boost converter U3 is connected between the VIN interface end and the SW interface end of the boost converter U3, and the inductor L2 is connected between the VIN interface end and the SW interface end of the boost converter U3. The EN interface end of the boost converter U3 is connected to one end of the resistor R11, and the inductor L2 is connected to the other end of the resistor R11. The EN interface end of the boost converter U3 is further connected to the input voltage end VCC_BAT. The input filter capacitor C6 is connected between the GND end of the boost converter U3 and the input voltage end VCC_BAT. The input filter capacitor C6 is grounded through the GND end of the boost converter U3. The SW interface end of the boost converter U3 is further connected to the diode D2, the output filter capacitors C9 and C10 in sequence. The FB interface end of the boost converter U3 is connected to the output regulating resistors R12 and R15. The other end of the output regulating resistor R12 is connected between the diode D2 and the output filter capacitor C9. The other end of the output regulating resistor R15 is grounded GND, and is further connected to the other ends of the output filter capacitors C9 and C10. The output end of the diode D2 outputs the boosted DC voltage VCC_12V. The output end of the diode D2 is further provided with a test point TP3.

[0128] The voltage stabilizer U2 is connected between the first interface end and the third interface end of the voltage stabilizer U2, and is further connected to the DC voltage VCC_12V. The second interface end of the voltage stabilizer U2 is grounded. The input filter capacitor C11 is connected in parallel between the second interface end and the first interface end of the voltage stabilizer U2. The fourth interface end of the voltage stabilizer U2 is connected to the output regulating resistors R13, R14 and R16. The fifth interface end of the voltage stabilizer U2 is connected to the other end of the output regulating resistor R13, the output filter capacitors C7 and C8 in sequence. The other end of the output regulating resistor R16 is connected to the second interface end of the voltage stabilizer U2. The other end of the output regulating resistor R14 is connected to the other end of the output filter capacitor C7, and the other end of the output filter capacitor C8 is connected to the other end of the output regulating resistor R16. The fifth interface end of the voltage stabilizer U2 finally outputs the DC voltage VCC_10V after being stepped down and stabilized, and the fifth interface end of the voltage stabilizer U2 is further provided with a test point TP5.

[0129] Generally, the boost circuit module is a power supply system composed of two-stage DC-DC conversion circuit, which realizes the functions of voltage boosting and linear voltage stabilizing respectively, solves the demand of stable output of 10V from low input voltage, and takes into account certain noise suppression and voltage accuracy, to provide stable voltage for silicon semiconductor detectors. Among them, the first stage is the boost circuit part based on boost converter U3 (MT3608 can be used); the core chip MT3608 is a commonly used boost converter, with a built-in power switch tube, which realizes low input voltage boosting through PWM control; VCC_BAT is the input voltage, and the input filter capacitor C6 (22μF) filters out the high-frequency noise in the input voltage to stabilize the input; the inductor L2 is the key component of the boost circuit, which stores energy when the switch tube is turned on and releases energy through the freewheeling diode when the switch tube is turned off, to realize voltage boosting; the diode D2 (B0505WS can be used) is used as a freewheeling element, which provides a path for inductor current when the switch tube is turned off, to ensure energy transmission to the output terminal, and at the same time, the one-way conductivity is used to prevent the output voltage from flowing back; the feedback and output adjusting R3 (100K) and R4 (2.5K) constitute a voltage dividing feedback network, which is connected to the FB pin of the boost converter chip; the output voltage VCC_12V is fed back to the chip after voltage division, compared with the reference voltage, and the chip adjusts the duty cycle of the switch tube to stabilize the output 12V voltage; the output filter capacitors C9 (10μF) and C10 (0.1μF) filter out the high-frequency ripple after boosting, to make the output VCC_12V smoother; the test point TP1 is used to measure the VCC_12V voltage or waveform, to facilitate debugging and detection;

[0130] The second stage is the linear voltage stabilizing circuit part based on the voltage stabilizing converter U2. The voltage stabilizing converter U2 uses the chip CAT4139JT, which is a linear voltage stabilizer (LDO) used to stabilize the 12V input and reduce it to 10V output, with low noise and high linear adjustment rate characteristics, for powering the silicon semiconductor detector;

[0131] The input filter capacitor C11 (2.2μF) is used for input filtering, to further filter out the residual ripple of the previous 12V voltage, to ensure that the voltage input to the LDO is pure; the output filter capacitors C7 (1μF) and C8 (1μF) are used for output filtering, to suppress the low-frequency noise of the LDO output and stabilize the 10V output voltage;

[0132] The output adjusting resistors R13 (110k) and R14 (10k) are used to set the output current limit or cooperate with the internal circuit of the chip to realize current detection; the output adjusting resistor R16 (15K) combines with the internal structure of the chip, which may participate in voltage feedback or bias setting, to ensure the stability of the 10V output;

[0133] The test points TP3 and TP5 are used to measure the voltage or waveform, to assist in debugging and verifying whether the output is normal.

[0134] In some embodiments, as shown in Figure 9 The storage circuit module includes:

[0135] The eighth interface end VCC of the erasable programmable read-only memory U4 is connected with the VCC_3V3 power supply; the seventh interface end WP of the erasable programmable read-only memory U4 is connected with the ground; the sixth interface end SCL of the erasable programmable read-only memory U4 is connected with the I2C_SCL of the system bus; and the fifth interface end SDA of the erasable programmable read-only memory U4 is connected with the I2C_SDA of the system data line.

[0136] Generally, the storage circuit module is an electrically erasable programmable read-only memory (EEPROM) based storage circuit module, realizing a data storage link of “single-chip MCU←I 2 C bus→AT24C64 EEPROM”, which is used for realizing non-volatile data storage in the system;

[0137] The electrically erasable programmable read-only memory (EEPROM) can adopt an AT24C64 with an I 2 C interface, a capacity of 64 Kbit (8 KB bytes), and support for working under a voltage of 2.5 V-5.5 V, and communication with the single-chip microcomputer through the I 2 C bus to realize writing and reading of data, and is used for storing configuration parameters, logs, and data required to be saved during power failure; wherein the eighth interface end VCC is connected with the system 3.3V power supply to supply power for the chip; the fourth interface end GND is used for grounding to provide a reference potential; the fifth interface end is connected with the I2C_SCL of the system I 2 C bus, SCL is an I 2 C clock line, which transmits a clock signal to synchronize data transmission and reception; SDA is an I 2 C data line, which is connected with the system I2C_SDA, and is used for reading and writing commands and storage content; address pins include A0, A1, and A2, which are I 2 C slave address setting pins, all of which are grounded in the circuit, so that the I 2 C slave address of the AT24C64 is fixed by hardware;

[0138] WP is a write protection control pin; I 2 The I 2C bus pull-up resistor R18 (4.7KΩ), R19 (4.7KΩ).

[0139] I2C_SCL, I2C_SDA can be used as test points, convenient for oscilloscope, logic analyzer to capture bus waveform, debug communication failure.

[0140] Some embodiments of the portable neutron personal dosimeter also include a host shell and a back clip; as Figure 10 As shown, the host shell includes an upper shell 2 and a lower shell 1, and is made of ABS engineering plastic with good plasticity, good thermal properties and stable chemical properties, with a density of only 1.18g / cm3, which is light and can ensure structural strength. The upper and lower edges and the left side wall of the host shell are designed with large arc surfaces, without sharp edges. The upper shell 2 is provided with a display screen 5, and a first button 6 and a second button 7 are arranged below the display screen 5. A through hole is provided above the display screen 5 for placing a buzzer 4 and an indicator light 3. The right side of the host shell has a battery cover 8 for taking out and placing the battery, and the edge of the battery cover is sealed with a silicone O-ring to increase waterproofness.

[0141] Generally, the host shell is sealed with an edge, and the inside is sprayed with an anti-electromagnetic interference coating to reduce electromagnetic interference. The joint between the upper and lower shells is sealed with a silicone O-ring to increase waterproofness. The silicon semiconductor detector and the nuclear electronics circuit are arranged inside the host shell. By optimizing the internal structure, the lightweight and portable requirements are achieved. The keys are composed of two key positions, and the operation process is simple and easy to use. Thin film keys are used, and the keys can switch real-time / cumulative dose rate display function, parameter setting menu function and power on / off operation. The display screen is an OLED screen with high brightness and high contrast, which can clearly display data in strong light or dim environment. The response time is short, and the content can be displayed in real time. A 14500 type rechargeable lithium battery is used to achieve the lightweight and portable requirements.

[0142] As shown in some embodiments, Figure 11 The switch control circuit module includes:

[0143] A MOS field effect transistor Q3; the source base S of the MOS field effect transistor Q3 is connected to BAT+, the drain D is connected to VCC_BAT, and the gate G and the source base S are further connected in parallel with a resistor R2; the gate G of the field effect transistor Q3 is further connected to the first interface end of the Schottky diode Q2 and the drain D of the MOS field effect transistor Q4, respectively; the gate G voltage of the field effect transistor Q3 controls its conduction / cutoff:

[0144] The second interface end of the Schottky diode Q2 is provided with a pull-up resistor R1, and the pull-up resistor R1 is further provided with a VCC_3V3 power supply.

[0145] The source S of the MOS field effect tube Q4 is provided with a ground GND, and the source S of the MOS field effect tube Q4 is provided with a resistor pull-down R10 and a current limiting resistor R8.

[0146] The pull-down resistor R10 and the current limiting resistor R8 are connected between the PWC point, and the second interface end of the Schottky diode Q2 and the resistor R1 are connected between the PWT point; usually, the switch control circuit module controls the MOS tube switch circuit of the battery power supply through a digital signal, and uses the complementary characteristics of the P-channel and N-channel MOS tubes, and cooperates with the diode and the resistor to realize the level logic conversion and the power supply control.

[0147] Figure 11 In the formula, Q3 is a P-channel MOS tube, which can be AO3401A, and is used as a main power supply switch, the source (S) of which is connected with the battery power supply BAT+, the drain (D) of which is connected with the load through VCC_BAT, and the gate (G) of which is controlled to be turned on / off: when the G voltage is lower than the S voltage by a certain threshold, Q3 is turned on, and VCC_BAT supplies power to the subsequent stage; otherwise, it is turned off; Q4 is an N-channel MOS tube, which is used as a control switch and can be AO3400, and cooperates with Q3 to realize the gate level control, and the N-channel characteristic is that the G voltage is higher than the S voltage by a certain threshold; Q2 is a Schottky diode, which can be BAT54C, and is used for level clamping and logic conversion, and the node level is adjusted by using the forward conduction voltage drop thereof; R1 (100K) is a pull-up resistor, which pulls up the G of Q3 to VCC_3V3 when Q4 is turned off, so that Q3 can be reliably turned off, and the gate is not suspended to cause false conduction; R8 (10K) is a current limiting resistor, which provides a suitable driving current for the G of Q4, and prevents the Q4 gate from being damaged by excessive current when the PWC level is abnormal; R10 (100K) is a pull-down resistor, which provides a stable potential for the S of Q4, and ensures the accuracy of the Q4 gate level detection; Q2 (BAT54C): Schottky diode, which uses the one-way conduction characteristic to assist the level state of the control circuit, and ensures that the elements work in a safe and suitable voltage range.

[0148] The working logic of the switch control circuit mainly has two states.

[0149] State 1: PWC is low

[0150] PWC low→ Q4's G terminal voltage is low→ Q4 (N channel) is off; Q3's G terminal voltage is pulled up by R1, VCC_3V3 through R1 (100K) to PWT node, and then through Q2's internal diode to Q3's G terminal→ Q3's G terminal voltage is close to VCC_3V3; Q3 is P channel, S terminal is connected to VCC_BAT, G terminal voltage is close to VCC_3V3, if VCC_BAT and VCC_3V3 voltage are close, then the voltage difference between G terminal voltage and S terminal voltage is small, Q3 is off→ the load in the back stage has no VCC_BAT power supply.

[0151] State 2: PWC is high

[0152] PWC high→ through R8 (10K) to Q4's G terminal→ Q4 (N channel) is on; after Q4 is on, Q3's G terminal is grounded through Q4→ Q3's G terminal voltage becomes low; Q3 is P channel, S terminal is connected to VCC_BAT, G terminal voltage is low→ meets the P channel on condition→ Q3 is on→ VCC_BAT supplies power to the back stage.

[0153] Generally, the key circuit module adopts a key de-bouncing input circuit, which converts the key action into a stable level signal by using the mechanical structure of a four-pin key + filter capacitor, for the host control system to detect. The key includes two thin film keys K1 and K2, which realize the switching on and off of the host, parameter setting, function setting, etc.

[0154] In some embodiments, as shown in Figure 12 the key circuit module includes:

[0155] The thin film key K1 has a second interface end and a third interface end connected in parallel with a filter capacitor C16; a fourth interface end is connected to the third interface end; a first interface end and a second interface end are provided with a key K1; and the second end of the thin film key K1 is further used to connect a switch control circuit of K1.

[0156] The thin film key K2 has a third interface end and a fourth interface end connected, and a first interface end provided with a parallel capacitor filter capacitor C17; a first interface end and a fourth interface end of the thin film key K2 are used to set a key K2; a third interface end and a fourth interface end of the thin film key K1, a third interface end and a fourth interface end of the thin film key K2 are provided with a ground GND; and a second interface end of the thin film key K2 is used to connect a switch control circuit of K2.

[0157] When the key is not pressed, the internal contact of the key is disconnected, and the key signal end is kept at a high level through the filter capacitors C16 and C17; when the key is pressed, the internal contact of the key is closed, the key signal end is directly grounded, the level becomes low, and the host control detects the key action.

[0158] Filter capacitors C16 and C17 (10nF, ceramic capacitors) are debounce capacitors. When a button is pressed / released, the mechanical contacts may briefly jitter, causing a rapid change in voltage level, which may be misinterpreted by the main controller as multiple button presses. The capacitors "smooth" the voltage level change through charging and discharging, absorbing the spike noise generated by the jitter, ensuring that the main controller detects a stable low level (pressed) or high level (released), thus achieving the "debounce" function.

[0159] In some embodiments, the information processing unit includes a microcontroller. Typically, the information processing unit includes a microcontroller (MCU) and peripheral control and debugging interface circuitry. For example, a minimum microcontroller system based on the FM33LG045 integrates power supply, clock, debugging, communication, and general-purpose I / O. The debugging and communication interface circuitry is a combined "SWD debugging + UART serial port" interface, accommodating both program development debugging and serial communication needs. The MCU needs to process and calculate the dose rate and cumulative dose from the acquired sensor signals. In some embodiments, the MCU is a 64MHz ARM Cortex-M0+ low-power processor, 256kB flash memory, 32kBSRAM, and rich interfaces and peripherals. Typical operating power consumption is 30130μA / MHz@48MHz. It has a built-in display driver module for driving OLED LCD screens, supporting 4, 6, and 8 COM, with maximum display segments of 176 segments (4COM), 252 segments (6COM), and 320 segments (8COM), respectively.

[0160] In addition, through the interconnected control of various components, functions such as audible and visual alarms for exceeding dose rate thresholds and cumulative dose storage are achieved. The device records the dose rate of the current environment in real time, refreshing the data every 2 seconds. When the dose rate exceeds the preset threshold, the device will issue a visual and audible alarm and display the alarm information on the screen. The device has the function of recording the cumulative dose rate, from zero to the current moment.

[0161] The portable neutron personal dosimeter disclosed in this invention has a simple structure, is easy to use, and can accurately detect neutron radiation, providing good protection for individuals. It has good application prospects in the field of neutron detection.

[0162] The technical solutions and technical details disclosed in the embodiments of this invention are merely illustrative of the inventive concept of this invention and do not constitute a limitation on the technical solutions of the embodiments of this invention. Any conventional changes, substitutions, or combinations made to the technical details disclosed in the embodiments of this invention have the same inventive concept as this invention and are within the protection scope of the claims of this invention.

Claims

1. A portable neutron personal dosimeter characterized in that, The utility model relates to a kind of neutron dosimeter, comprising: Silicon semiconductor detector unit for detecting neutron radiation and generating corresponding electrical signals; Pre-amplifier unit, connected with the silicon semiconductor detector unit, for processing the detected neutron radiation electrical signals and converting into pulse signals; Information processing unit, configured to connect with the pre-amplifier unit, for processing pulse signals and outputting neutron dose information; Power supply circuit unit for providing appropriate voltage to the silicon semiconductor detector unit, the pre-amplifier unit and the information processing unit respectively; Display unit, connected with the information processing unit, for displaying neutron dose information; Alarm unit, connected with the information processing unit, for outputting alarm signals.

2. The portable neutron dosimeter of claim 1, wherein, The pre-amplifier unit comprises: Pre-amplifier module for amplifying neutron radiation electrical signals; Shaping filter module for filtering amplified neutron radiation electrical signals; Voltage amplifier module for amplifying filtered radiation electrical signals; Discrimination comparator module for converting amplified neutron radiation electrical signals into stable radiation signals.

3. The portable neutron personal dosimeter of claim 2, wherein, The pre-amplifier module comprises: Operational amplifier (U6); The fifth interface end and the sixth interface end of the operational amplifier (U6) are connected, and further connected with a power filter bead (FB1), which is further connected with a VCC_3V3A power supply; The fifth interface end and the sixth interface end of the operational amplifier (U6) are further connected with parallel power filter capacitors (C24, C25, C26), and the parallel power filter capacitors (C24, C25, C26) are further grounded; The third interface end of the operational amplifier (U6) is connected with an electrostatic protection diode (D5), a feedback resistor (R28) and a source electrode of a field effect transistor (Q7) in sequence;The other end of the feedback resistor (R28) is connected with a VCC_3V3A power supply;The electrostatic protection diode (D5) is further grounded;The drain electrode of the field effect transistor (Q7) is connected with parallel resistors (R43) and capacitors (C44), and the other ends of the parallel resistors (R43) and capacitors (C44) are grounded; The fourth interface end of the operational amplifier (U6) is connected with parallel compensation filter capacitors (C39) and compensation filter resistors (R37), and the parallel compensation filter capacitors (C39) and compensation filter resistors (R37) are further connected with the second interface end of the operational amplifier (U6) and grounded;The fourth interface end of the operational amplifier (U6) is also connected with a feedback resistor (R29), and the other end of the feedback resistor (R29) is connected with the fifth interface end and the sixth interface end of the operational amplifier (U6); The gate electrode of the field effect transistor (Q7) is connected with parallel phase compensation resistors (R26) and phase compensation capacitors (C30), and the parallel phase compensation resistors (R26) and phase compensation capacitors (C30) are further connected with the first interface end of the operational amplifier (U6). The gate of the field effect tube (Q7) is further provided with a direct current isolation coupling capacitor (C35) connected with a voltage division current limiting resistor (R31), a voltage division current limiting resistor (R27) and a VCCA_10V power supply in sequence; a coaxial interface (J2) is arranged between the direct current isolation coupling capacitor (C35) and the voltage division current limiting resistor (R31), and the coaxial interface (J2) is grounded; an input filter capacitor (C29) is arranged between the voltage division current limiting resistor (R31) and the voltage division current limiting resistor (R27), and the input filter capacitor (C29) is further grounded; an input filter capacitor (C27) is arranged between the voltage division current limiting resistor (R27) and the VCCA_10V power supply, and the input filter capacitor (C27) is further grounded.

4. The portable neutron personal dosimeter of claim 2, wherein, The shaped filter module comprises: an operational amplifier (U7A); an eighth interface end of the operational amplifier (U7A) is provided with a power supply filter magnetic bead (FB2) connected with a VCC_3V3A power supply; and the eighth interface end of the operational amplifier (U7A) is further provided with a parallel power supply filter capacitor (C28, C31) connected in parallel, and the parallel power supply filter capacitor (C28, C31) is further grounded; a third interface end of the operational amplifier (U7A) is provided with a phase compensation / filter capacitor (C38), a voltage division current limiting resistor (R34), a high-frequency filter capacitor (C37), a voltage division current limiting resistor (R33), a filter capacitor (C33) and a filter resistor (R32) connected in sequence; the phase compensation / filter capacitor (C38) is further grounded; and a resistor (R40) and a capacitor (C36) are arranged between the voltage division current limiting resistor (R33) and the filter capacitor (C33), and the resistor (R40) is further grounded; a second interface end of the operational amplifier (U7A) is provided with a feedback resistor (R44, R47); the feedback resistor (R47) is further grounded, and the feedback resistor (R44) is further provided with a feedback resistor (R45) connected with the first interface end of the operational amplifier (U7A); and the high-frequency filter capacitor (C37) is further connected between the feedback resistor (R44) and the feedback resistor (R45); the first interface end of the operational amplifier (U7A) is further provided with a capacitor (C34) connected with a parallel phase compensation capacitor (C42) and a phase compensation resistor (R41), and the other end of the parallel phase compensation capacitor (C42) and the phase compensation resistor (R41) is grounded.

5. The portable neutron personal dosimeter of claim 2, wherein, The voltage amplifier module comprises: an operational amplifier (U7B); a fifth interface end of the operational amplifier (U7B) is provided for connecting a previous stage circuit; The sixth interface end of the operational amplifier (U7B) is provided with a feedback resistor (R39) and a phase compensation capacitor (C43) connected in parallel, and is further provided with an input current limiting / biasing resistor (R46) and an input filter capacitor (C45) connected in sequence, and the input filter capacitor (C45) is further grounded, and the feedback resistor (R39) and the phase compensation capacitor (C43) connected in parallel are further connected to the seventh interface end of the operational amplifier (U7B); and the seventh interface end of the operational amplifier (U7B) is further provided with an output current limiting resistor (R35).

6. The portable neutron personal dosimeter of claim 2, wherein, The discrimination comparator module comprises: an operational amplifier (U8); The third interface end of the operational amplifier (U8) is provided with a filter resistor R38 and a filter capacitor (C40) connected in parallel; the filter resistor (R38) and the filter capacitor (C40) connected in parallel are further connected to the second interface end of the operational amplifier (U8) and are grounded; The fourth interface end of the operational amplifier (U8) is provided with an amplification resistor (R42), and the amplification resistor (R42) is further connected to the second interface end of the operational amplifier (U8); The first interface end of the operational amplifier (U8) is provided with a filter shaping resistor (R36), and the filter shaping resistor (R36) is provided with a filter shaping capacitor (C41), and the filter shaping capacitor (C41) is further connected to the second interface end of the operational amplifier (U8); a post-stage circuit is provided between the filter shaping resistor (R36) and the filter shaping capacitor (C41), and a shaped stable radiation signal is transmitted to the post-stage circuit; The fifth interface end of the operational amplifier (U8) is provided with an amplification resistor (R30) and a power supply filter capacitor (C32), and the power supply filter capacitor (C32) is further grounded, and the amplification resistor (R30) is further connected to the fourth interface end of the operational amplifier (U8); the amplification resistor (R30) and the power supply filter capacitor (C32) are connected to the VCC_3V3A power supply.

7. The portable neutron personal dosimeter of claim 1, wherein, The power supply circuit unit comprises a step-down circuit module, a step-up circuit module, a storage circuit module, a switch control circuit module, a key circuit module, and a display screen interface circuit module.

8. The portable neutron personal dosimeter of claim 7, wherein, The step-down circuit module comprises: a DC-DC converter (U1); The first interface end and the fourth interface end of the DC-DC converter (U1) are connected, and the second interface end of the DC-DC converter (U1) is grounded; an input filter capacitor (C1) is connected in parallel between the second interface end and the first interface end of the DC-DC converter (U1); and the input filter capacitor (C1) and the first interface end and the fourth interface end are further connected to an input voltage end VCC_BAT. The third interface end of the DC-DC converter (U1) is connected with the inductor (L1), the inductor (L1) is further connected with the feedback and output adjusting resistor (R4) and one end of the output filter capacitor (C2, C3, C4) in sequence, and is further connected with the output voltage end VCC_3V3; The fifth interface end of the DC-DC converter (U1) is connected with the feedback and output adjusting resistor (R7) arranged between the second interface end, the other end of the feedback and output adjusting resistor (R4) and the other end of the output filter capacitor (C2); and the other end of the output filter capacitor (C3, C4) is connected with the ground; The two ends of the output filter capacitor (C4) are further connected with the two ends of the protection diode (D1) respectively.

9. The portable neutron personal dosimeter of claim 7, wherein, The boost circuit module comprises: The boost converter (U3); The inductor (L2) is arranged between the VIN interface end and the SW interface end of the boost converter (U3); the EN interface end of the boost converter (U3) is connected with one end of the resistor (R11), the inductor (L2) and the other end of the resistor (R11) are connected, and the input voltage end VCC_BAT is further connected; The input filter capacitor (C6) is arranged between the GND end of the boost converter (U3) and the input voltage end VCC_BAT, and the input filter capacitor (C6) is connected with the ground of the GND end of the boost converter (U3); The SW interface end of the boost converter (U3) is further connected with the diode (D2) and the output filter capacitor (C9, C10) in sequence; the FB interface end of the boost converter (U3) is connected with the output adjusting resistor (R12, R15), the other end of the output adjusting resistor (R12) is connected between the diode (D2) and the output filter capacitor (C9), the other end of the output adjusting resistor (R15) is connected with the ground (GND), and is further connected with the other end of the output filter capacitor (C9, C10); the output end of the diode (D2) outputs the boosted direct current voltage VCC_12V; The voltage stabilizing converter (U2); The first interface end and the third interface end of the voltage stabilizing converter (U2) are connected, and are further connected with the direct current voltage VCC_12V; the second interface end of the voltage stabilizing converter (U2) is connected with the ground; the input filter capacitor (C11) is arranged in parallel between the second interface end and the first interface end of the voltage stabilizing converter (U2). The fourth interface end of the voltage stabilizing converter (U2) is provided with an output adjusting resistor (R13, R14, R16); the fifth interface end of the voltage stabilizing converter (U2) is sequentially provided with the other end of the output adjusting resistor (R13) and one end of an output filter capacitor (C7, C8); the other end of the output adjusting resistor (R16) is provided with the second interface end of the voltage stabilizing converter (U2); the other end of the output adjusting resistor (R14) is provided with the other end of the output filter capacitor (C7), and the other end of the output filter capacitor (C8) is provided with the other end of the output adjusting resistor (R16); and the fifth interface end of the voltage stabilizing converter (U2) finally outputs a DC voltage VCC_10V after voltage reduction and voltage stabilization.

10. The portable neutron personal dosimeter of claim 7, wherein, The storage circuit module comprises: an erasable programmable read-only memory (U4); the first interface end, the second interface end, the third interface end and the fourth interface end of the erasable programmable read-only memory (U4) are connected and grounded; the eighth interface end of the erasable programmable read-only memory (U4) is provided with a VCC_3V3 power supply; the seventh interface end of the erasable programmable read-only memory (U4) is grounded; the sixth interface end of the erasable programmable read-only memory (U4) is provided with an I2C_SCL of a system bus; and the fifth interface end of the erasable programmable read-only memory (U4) is provided with an I2C_SDA of a system data line.

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