Particle radiation detection device

Abstract

The embodiment of the present application provides a particle radiation detection device, comprising: a detection module and a readout module, wherein the detection module is adapted to detect particle radiation and convert into an initial electrical signal; the readout module is coupled with the detection module and is adapted to output a detection signal based on the initial electrical signal; the coupling mode between the detection module and the readout module is determined based on the size of the detection module, so that the noise of the detection signal is less than a preset noise threshold. By using the above technical scheme, the noise of the detection signal can be reduced.

Description

Technical Field

[0001] This invention relates to the field of particle radiation detection technology, and more particularly to a particle radiation detection device. Background Technology

[0002] In the research and experiments of particle radiation detection, the noise of the detection signal is an important indicator for evaluating the detection performance of particle radiation detection devices. In practical applications, it is desirable to reduce the noise of the detection signal.

[0003] In existing technologies, particle radiation detection devices convert detected particle radiation signals into corresponding electrical signals, process these signals, and output a final detection signal. During signal processing, the particle radiation detection device continuously introduces new noise sources, causing the signal noise to gradually increase as it propagates within the device. Therefore, reducing the noise of the detection signal is a pressing issue that needs to be addressed.

[0004] The content in the background section is merely technology known to the public and does not necessarily represent existing technology in this field. Summary of the Invention

[0005] In view of this, embodiments of the present invention provide a particle radiation detection device that can reduce the noise of the detection signal.

[0006] This invention provides a particle radiation detection device, comprising:

[0007] The detection module is suitable for detecting particle radiation and converting it into an initial electrical signal;

[0008] The readout module, coupled to the detection module, is adapted to output a detection signal based on the initial electrical signal;

[0009] The coupling method between the detection module and the readout module is determined based on the size of the detection module, so that the noise of the detection signal is less than a preset noise threshold.

[0010] Optionally, the detection module includes:

[0011] The detector is coupled to an external power supply and the input terminal of the readout module, respectively, and is suitable for detecting particle radiation and converting it into an initial electrical signal.

[0012] Optionally, the coupling method between the detector and the readout module is determined based on the thickness and area of ​​the detector.

[0013] Optionally, when the thickness of the detector is less than a preset first thickness threshold and the area is greater than a preset first area threshold, the detector is DC coupled to the readout module.

[0014] Optionally, when the thickness of the detector is greater than a preset second thickness threshold and the area is less than a preset second area threshold, the coupling mode between the detector and the readout module is determined based on the stray capacitance between the detector and the readout module.

[0015] Optionally, when the stray capacitance is greater than a preset threshold, the detector is AC coupled to the readout module;

[0016] When the stray capacitance is less than or equal to the preset threshold, the detector is DC coupled to the readout module.

[0017] Optionally, the detector is AC-coupled with the readout module, and the detection device further includes:

[0018] A coupling module, coupled between the detection module and the readout module, is adapted to block the DC signal in the initial electrical signal and allow the AC signal in the initial electrical signal to pass through.

[0019] Optionally, the readout module includes:

[0020] An amplification unit, coupled to the detection module, is adapted to amplify the initial electrical signal and output the detection signal;

[0021] A feedback unit, connected in parallel with the amplification unit, is adapted to feed back the detection signal output by the amplification unit to the input terminal of the amplification unit.

[0022] Optionally, the amplification unit includes:

[0023] An operational amplifier, coupled to the detection module, is adapted to output the detection signal;

[0024] The junction field-effect transistor has its gate coupled to the output terminal of the detection module, its source grounded, and its drain coupled to the external power supply and the input terminal of the operational amplifier, respectively.

[0025] Optionally, the feedback unit includes:

[0026] The feedback resistor is connected in parallel with the amplification unit;

[0027] The feedback capacitor is connected in parallel with the amplification unit.

[0028] The particle radiation detection device in this embodiment of the invention detects particle radiation through the detection module and converts the detected particle radiation into an initial electrical signal, which is then output to the readout module. The readout module outputs the detection signal based on the initial electrical signal. The coupling method between the detection module and the readout module is determined according to the size of the detection module, so that the noise of the detection signal is less than a preset noise threshold. Experiments have shown that the above scheme can reduce the noise of the detection signal and improve the detection performance of the particle radiation device.

[0029] Furthermore, when the thickness of the detector is less than a preset first thickness threshold and its area is greater than a preset first area threshold, DC coupling occurs between the detector and the readout module. Experiments have shown that the above scheme can reduce the noise of the detection signal.

[0030] Furthermore, if the stray capacitance is greater than a preset threshold, the detector is AC-coupled with the readout module; if the stray capacitance is less than or equal to the preset threshold, the detector is DC-coupled with the readout module. Experiments have shown that the above scheme can reduce the noise of the detection signal. Attached Figure Description

[0031] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments of the present invention or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this specification. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 A schematic diagram of a particle radiation detection device according to an embodiment of the present invention is shown.

[0033] Figure 2A A schematic diagram of the specific structure of a particle radiation detection device using DC coupling in an embodiment of the present invention is shown.

[0034] Figure 2B It shows Figure 2A The diagram shows a noise model of the particle radiation detection device.

[0035] Figure 3A A schematic diagram of the specific structure of a particle radiation detection device using an AC coupling method in an embodiment of the present invention is shown.

[0036] Figure 3B It shows Figure 3A The diagram shows a noise model of the particle radiation detection device.

[0037] Figure 4AThe FWHM particle radiation detection device with a first detector configured in an AC coupling configuration is shown in an embodiment of the present invention. AC A schematic diagram showing the relationship between stray capacitance and the curve.

[0038] Figure 4B The FWHM particle radiation detection device with a first detector configured in a DC-coupled configuration is shown in an embodiment of the present invention. DC A schematic diagram showing the relationship between stray capacitance and the curve.

[0039] Figure 4C It shows Figure 4A and Figure 4B The diagram shows the difference curves between the FWHM and stray capacitance of the particle radiation detection device with the first detector in AC coupling and DC coupling conditions.

[0040] Figure 4D It shows Figure 4A and Figure 4B A schematic diagram showing the relative difference curves between the FWHM and stray capacitance of the particle radiation detection device with the first detector set up under AC coupling and DC coupling conditions.

[0041] Figure 5A The FWHM particle radiation detection device with a second detector configured in an AC coupling configuration is shown in an embodiment of the present invention. AC A schematic diagram showing the relationship between stray capacitance and the curve.

[0042] Figure 5B The FWHM particle radiation detection device with a second detector in DC coupling configuration is shown in an embodiment of the present invention. DC A schematic diagram showing the relationship between stray capacitance and the curve.

[0043] Figure 5C It shows Figure 5A and Figure 5B The diagram shows the difference curves between FWHM and stray capacitance of the particle radiation detection device with the second detector in AC coupling and DC coupling conditions.

[0044] Figure 5D It shows Figure 5A and Figure 5B The diagram shows the relative difference curves between FWHM and stray capacitance for the particle radiation detection device with the second detector in both AC coupling and DC coupling conditions.

[0045] Figure 6The diagram shows the relationship between the output voltage and stray capacitance of the particle radiation detection device with a first detector in an embodiment of the present invention under AC coupling and DC coupling conditions.

[0046] Figure 7 The diagram shows the relationship between the output voltage and stray capacitance of the particle radiation detection device with a second detector in an embodiment of the present invention under AC coupling and DC coupling conditions.

[0047] Figure 8 The diagram shows the corresponding curves of the signal-to-noise ratio and stray capacitance of the particle radiation detection device with a first detector in an embodiment of the present invention under AC coupling and DC coupling conditions.

[0048] Figure 9 The diagram shows the corresponding curves of the signal-to-noise ratio and stray capacitance of the particle radiation detection device with a second detector in an embodiment of the present invention under AC coupling and DC coupling conditions.

[0049] Figure 10 It shows Figure 8 and Figure 9 A schematic diagram showing the relative difference curves between the signal-to-noise ratio and stray capacitance of the particle radiation detection device under different coupling conditions when the detector is set with detectors of different sizes. Detailed Implementation

[0050] As described in the background section, in the research and experiments on space particle radiation detection, the noise of the detection signal is an important indicator for evaluating the detection performance of particle radiation detection devices, and it is desirable to reduce the noise of the detection signal in practical applications.

[0051] However, during research and experimentation, the inventors discovered that as the signal is transmitted within the particle radiation detection device, the noise gradually increases. This is because the particle radiation detection device continuously introduces new noise sources during signal processing, thus causing the signal noise to gradually increase. Therefore, how to reduce the noise of the detection signal is an urgent problem to be solved.

[0052] To address the aforementioned technical problems, the present invention provides a particle radiation detection device, as described above. Figure 1 The particle radiation detection device 100 may include: a detection module 110 and a readout module 120, wherein:

[0053] The detection module 110 is adapted to detect particle radiation and convert it into an initial electrical signal;

[0054] The readout module 120 is coupled to the detection module 110 and is adapted to output a detection signal based on the initial electrical signal;

[0055] The coupling method between the detection module and the readout module is determined based on the size of the detection module, so that the noise of the detection signal is less than a preset noise threshold.

[0056] Using the above technical solution, the particle radiation detection device detects particle radiation through the detection module and converts the detected particle radiation into an initial electrical signal, which is then output to the readout module. The readout module outputs the detection signal based on the initial electrical signal. The coupling method between the detection module and the readout module is determined according to the size of the detection module, so that the noise of the detection signal is less than a preset noise threshold. Experiments have shown that the above solution can reduce the noise of the detection signal and improve the detection performance of the particle radiation device.

[0057] In practice, the coupling can be implemented in various ways, such as electrical connection, wired connection, and wireless connection. Other examples include direct connection and indirect connection.

[0058] In specific implementation, when the size of the detection module is fixed, different coupling methods between the detection module and the readout module result in different noise levels in the corresponding detection signals. The preset noise threshold may include the smaller noise value among the two output detection signals when the coupling methods between the detection module and the readout module are different.

[0059] In a specific implementation, the detection module may include a detector, which is coupled to an external power supply and the input terminal of the readout module, respectively, and is suitable for detecting particle radiation and converting it into an initial electrical signal.

[0060] In specific implementation, the coupling method between the detection module and the readout module is determined based on the size of the detection module, and may include: the coupling method between the detector and the readout module is determined based on the thickness and area of ​​the detector.

[0061] In some embodiments of the present invention, when the thickness of the detector is less than a preset first thickness threshold and the area is greater than a preset first area threshold, DC coupling occurs between the detector and the readout module. Experiments have shown that the above solution can reduce the noise of the detection signal.

[0062] In other embodiments of the present invention, when the thickness of the detector is greater than a preset second thickness threshold and the area is less than a preset second area threshold, the coupling mode between the detector and the readout module is determined based on the stray capacitance between the detector and the readout module.

[0063] Specifically, if the stray capacitance is greater than a preset threshold, the detector is AC-coupled with the readout module; if the stray capacitance is less than or equal to the preset threshold, the detector is DC-coupled with the readout module. Experiments have shown that this scheme can reduce the noise of the detection signal.

[0064] In a specific implementation, the detector is AC coupled to the readout module. The particle radiation detection device 100 further includes a coupling module 130, which is coupled between the detection module 110 and the readout module 120 and is adapted to block the DC signal in the initial electrical signal and allow the AC signal in the initial electrical signal to pass through.

[0065] To enable those skilled in the art to better understand and implement this device, the following specific examples illustrate the specific structure of the particle radiation detection device.

[0066] In some embodiments of the present invention, reference is made to... Figure 2A The particle radiation detection device adopts a DC coupling method. The particle radiation detection device 100 may include a detection module 110 and a readout module 120.

[0067] In a specific implementation, the detection module 110 includes a detector. Specifically, the detector may include a photodetector. As an optional example, the photodetector may be an avalanche photodiode (APD), a single-photon avalanche photodiode (SPAD), a silicon photomultiplier (SiPM), or other photodetectors.

[0068] It is understood that the embodiments of the present invention do not limit the specific structure of the detector, as long as the detector can detect particle radiation and convert it into an initial electrical signal.

[0069] In a specific implementation, the readout module 120 may include an amplification unit coupled to the output terminal of the detection module, adapted to amplify the signal at the input terminal of the readout module and output the detection signal. As an optional example, the amplification unit may include one or more of operational amplifiers, junction field-effect transistors, or other amplifying devices.

[0070] As a specific example, the amplification unit may include the operational amplifier and a junction field-effect transistor (JFET). The operational amplifier is coupled to the detection module, and the JFET is coupled between the detection module and the operational amplifier. By continuously amplifying the initial electrical signal through the two-stage amplification unit composed of the JFET and the operational amplifier, a higher amplification factor can be obtained, thereby increasing the strength of the output signal.

[0071] Furthermore, in a specific implementation, the readout module may further include a feedback unit connected in parallel with the amplification unit, adapted to feed back the detection signal output by the amplification unit to the input terminal of the amplification unit. As an optional example, the feedback unit may include one or more of a feedback resistor, a feedback capacitor, or other feedback devices.

[0072] As a specific example, the feedback unit may include the feedback resistor and the feedback capacitor, wherein the feedback resistor is connected in parallel with the amplification unit and is adapted to limit the amplification factor of the amplification unit based on the detection signal output by the amplification unit to prevent the amplification unit from entering a locked state; the feedback capacitor is connected in parallel with the amplification unit and is adapted to reduce the high-frequency noise gain of the amplification unit and improve the signal SNR based on the detection signal output by the amplification unit.

[0073] In other embodiments of the present invention, reference is made to Figure 2B The particle radiation detection device adopts an AC coupling method. The particle radiation detection device 100 may include: a detection module 110, a coupling module 130, and a readout module 120.

[0074] In a specific implementation, the detection module 110 includes a detector.

[0075] In a specific implementation, the detection module 110 may further include: a first bias resistor, which is coupled between the detector and an external power supply and is adapted to adjust the voltage on the detector. In an optional example, the external power supply supplies power to the detector through the first bias resistor, and by selecting an appropriate resistance value, the first bias resistor adjusts the voltage on the detector, enabling the detector to operate at a safe voltage.

[0076] As an optional example, the external power supply can be a DC power supply, and correspondingly, the electrical signal output by the external power supply is a DC signal. Therefore, the initial electrical signal output by the detection module can include the initial electrical signal output by the detector after conversion and the electrical signal output by the external power supply.

[0077] In a specific implementation, the coupling module 130 may include a coupling capacitor, suitable for filtering the electrical signal input to the input terminal. In an optional example, the coupling module may block the DC signal in the initial electrical signal output by the detector, allowing the AC signal in the initial electrical signal to pass through, thereby avoiding interference caused by the DC signal in the initial electrical signal to the readout module.

[0078] In a specific implementation, the readout module 120 may include an amplification unit coupled to the output terminal of the coupling module, adapted to amplify the signal at the input terminal of the readout module and output the detection signal. As an optional example, the amplification unit may include one or more of an operational amplifier, a junction field-effect transistor, or other amplifying devices. Specific examples are given above and will not be repeated here.

[0079] To enable those skilled in the art to better understand and implement this device, the following specific examples will further illustrate the specific structure of the particle radiation detection device.

[0080] In some embodiments of the present invention, reference continues to be made to... Figure 2A The particle radiation detection device employs DC coupling. The particle radiation detection device 100 may include a detection module 110 and a read / write module 120. The detection module 110 may include a detector D. e The readout module 120 may include: a junction field-effect transistor JF and a second bias resistor R. d Operational amplifier A m Feedback resistor R f and feedback capacitor C f .

[0081] Specifically, the detector D e , respectively connected to external power supply V bias1 The junction field-effect transistor JF is coupled to its gate g, which is suitable for detecting particle radiation and outputting an initial electrical signal.

[0082] The source s of the junction field-effect transistor JF is grounded, and the drain d is connected to the external power supply V. bias2 and the operational amplifier A m The inverting input terminal is coupled to the operational amplifier A, which is suitable for supplying power to the operational amplifier A. m The output is an amplified electrical signal; the second bias resistor R d Coupled to external power supply V bias2 Between the drain d and the drain d, it is suitable to adjust the voltage at the drain d of the junction field-effect transistor JF.

[0083] The operational amplifier A mThe inverting input terminal is coupled to the drain d, and its non-inverting input terminal is grounded, which is suitable for further amplifying the electrical signal output by the junction field-effect transistor JF.

[0084] The feedback resistor R f The gate g of the junction field-effect transistor JF and the operational amplifier A are coupled together. m Between the output terminals, it is suitable for reducing the voltage difference between the junction field-effect transistor JF and the operational amplifier A. m The magnification factor increases the stability of the particle radiation detection device; the feedback capacitor C f The gate g of the junction field-effect transistor JF and the operational amplifier A are coupled together. m Between the output terminals and the feedback resistor R f Parallel connection is suitable for reducing the voltage drop between the junction field-effect transistor JF and the operational amplifier A. m The resulting high-frequency noise gain.

[0085] In a specific implementation, the electrical signal output by the detector after conversion can be a pulse signal. As an optional example, the pulse signal can be a current pulse signal. The junction field-effect transistor (JFET) is a voltage-controlled device; correspondingly, the voltage pulse signal corresponding to the AC signal of the current pulse signal acts at the gate of the JFET. The electrical signal output by the JFET is a pre-amplified voltage pulse signal, and the detection signal output by the operational amplifier is a secondary amplified voltage pulse signal.

[0086] Continue to refer to Figure 2A Based on the material properties of the device, the detector has a detector node capacitance C. d The circuit between the detector and the junction field-effect transistor has a stray capacitance C. s The junction field-effect transistor has an input capacitance C. g The stray capacitance C s The size of each is proportional to the size of the circuit between the detector and the junction field-effect transistor.

[0087] Assuming the detector D e If a current pulse signal with an output charge of Q is generated, then the output signal V of the particle radiation detection device under DC coupling is... outDC for:

[0088]

[0089] Wherein, the charge Q is proportional to the deposited energy of the particle remaining in the detector, and A corresponds to the junction field-effect transistor and the operational amplifier A. m The common open-loop gain has a value much greater than 1; for example, the value of A can range from 10 to 10.5 -10 6 .

[0090] Reference Figure 2B Based on device characteristics, the detector D in the noise model e The junction field-effect transistor JF and the second bias resistor R d and the feedback resistor R f Both can be used as noise sources to introduce noise during signal processing.

[0091] Specifically, the detector D e There is a leakage current i d Shot noise caused The junction field-effect transistor JF has a leakage current i g Shot noise caused Channel thermal noise and flicker noise The second bias resistor R d Thermal noise exists The feedback resistor R f Thermal noise exists Wherein: the shot noise The value is 2i d df, the shot noise The value is 2i d df, the thermal noise The value is 4 / R f df, the flicker noise The value is K F / g f)df, the thermal noise The value is The thermal noise of the channel The value is 8 / (3) m )df.

[0092] In practice, all noise sources are mapped to the input terminal of the amplification unit (the gate of the junction field-effect transistor).

[0093] Specifically, the shot noise shot noise and the thermal noise All of these are current noise mapped to the input terminal of the amplification unit. The corresponding noise source can be equivalent to a current source. Therefore, the noise signal output by the aforementioned equivalent current source during DC coupling is... for:

[0094]

[0095] Where ω represents the radian frequency, and its value is equal to 2*i*.

[0096] The flicker noise The thermal noise of the channel and the thermal noise The voltage noise mapped to the input of the amplification unit can be represented by an equivalent voltage source. Therefore, during DC coupling, the noise signal output by the aforementioned equivalent voltage source... for:

[0097]

[0098] In the case of DC coupling, the output terminal of the amplification unit (the output terminal of the operational amplifier) ​​outputs the total noise signal. for:

[0099]

[0100] In a specific implementation, in order to obtain quantifiable noise of the detection signal, a CR-RC shaping network can be connected to the output of the particle radiation detection device. This network can be coupled to the output of the operational amplifier and is suitable for converting noise signals into shaped signals. Based on the processing of the shaped signals, the noise of the detection signal can be quantified.

[0101] As an optional example, the noise signal output by the amplification unit The signal is transmitted to the CR-RC forming network, processed by the CR-RC forming network, and then output as a forming signal. Its value is:

[0102]

[0103] Where, A(ω)=0ωτ / (1+ 2 τ 2 A0 represents the network gain constant, ω represents the radian frequency, and its value is equal to 2*i*. τ is the forming time constant of the CR-RC forming network.

[0104] To calculate the equivalent noise comparable to actual measurements, the equivalent noise charge (ENC) and the full-width at the half of the maximum (FWHM) are used. For DC coupling, the corresponding ENC is... DC and FWHM DC They are respectively:

[0105]

[0106] FWHM DC =2.35W / ENCDC (7)

[0107] Where e represents the natural logarithm, which has a value of 2.718, and W represents the average ionization energy (the corresponding value for silicon detectors is 3.62 eV).

[0108] At the same time, through the output signal With forming signal The ratio can also be used to obtain the signal-to-noise ratio (SNR) of the probe signal under DC coupling. DC The signal-to-noise ratio (SNR) of the detection signal DC for:

[0109]

[0110] In other embodiments of the present invention, reference continues to be made. Figure 3A The particle radiation detection device employs AC coupling. The particle radiation detection device 100 may include a detection module 110, a readout module 120, and a coupling module 130. The detection module 110 may include a detector D. e The coupling module 130 may include a coupling capacitor C. X The readout module 120 may include: a junction field-effect transistor JF and a second bias resistor R. d Operational amplifier A m Feedback resistor R f and feedback capacitor C f .

[0111] Specifically, the detector D e , respectively connected to external power supply V bias1 and the coupling capacitor C X The input terminal is coupled, suitable for detecting particle radiation and outputting an electrical signal; the first bias resistor R b Coupled to an external power supply and the detector D e Between, suitable for adjusting the detector D e The voltage on it.

[0112] The coupling capacitor C X Coupled to the detector D e Between the junction field-effect transistor JF and the detector D, it is suitable for blocking the detector D. e The initial electrical signal output after conversion and the external power supply V bias1 The DC signal in the output electrical signal passes through the detector D. e The AC signal in the initial electrical signal output after conversion.

[0113] The gate g of the junction field-effect transistor JF is coupled to the coupling capacitor C. XThe output terminal is coupled, the source s is grounded, and the drain d is connected to the external power supply V. bias2 and the operational amplifier A m The inverting input terminal is coupled to the operational amplifier A, which is suitable for supplying power to the operational amplifier A. m The output is an amplified electrical signal; the second bias resistor R d Coupled to external power supply V bias2 Between the drain d and the drain d, the voltage at the drain d of the junction field-effect transistor JF can be adjusted. The operational amplifier A m The inverting input terminal is coupled to the drain d, and its non-inverting input terminal is grounded, which is suitable for further amplifying the electrical signal output by the junction field-effect transistor JF.

[0114] The feedback resistor R f The gate g of the junction field-effect transistor JF and the operational amplifier A are coupled together. m Between the output terminals, it is suitable for reducing the voltage difference between the junction field-effect transistor JF and the operational amplifier A. m The magnification factor increases the stability of the particle radiation detection device; the feedback capacitor C f The gate g of the junction field-effect transistor JF and the operational amplifier A are coupled together. m The output terminal is connected to the feedback resistor R. f Parallel connection is suitable for reducing the voltage drop between the junction field-effect transistor JF and the operational amplifier A. m The resulting high-frequency noise gain.

[0115] Based on the material properties of the device, the detector has a detector node capacitance C. d The circuit between the detector and the coupling capacitor has a stray capacitance C. s1 The line between the coupling capacitor and the junction field-effect transistor has a stray capacitance C. s2 The junction field-effect transistor has an input capacitance C. g The stray capacitance C s1 and the stray capacitance C s2 The size of each is proportional to the size of the corresponding line.

[0116] Continue to refer to Figure 3A In conjunction with other devices in the particle radiation detection device, from the detector D e The equivalent capacitance C from the output terminal to the gate g of the junction field-effect transistor JF in1 for:

[0117] C in1 = (C g +C s2 +(1+A)C f C x / (C x +C g +C s2 +(1+A)C f (9)

[0118] Assuming the detector D e If a current pulse signal with an output charge of Q is generated, then the output signal V of the particle radiation detection device during AC coupling is... outAC for:

[0119]

[0120] Wherein, the charge Q is proportional to the deposited energy of the particle remaining in the detector, and A corresponds to the junction field-effect transistor and the operational amplifier A. m The common open-loop gain has a value much greater than 1; for example, the value of A can range from 10 to 10. 5 -10 6 .

[0121] Reference Figure 3B Based on device characteristics, the detector D described in the AC noise model e The first bias resistor R b The junction field-effect transistor JF and the second bias resistor R d and the feedback resistor R f Both can be used as noise sources to introduce noise during signal processing.

[0122] Specifically, the detector D e There is a leakage current i d Shot noise caused The first bias resistor R b Thermal noise exists The junction field-effect transistor JF has a leakage current i g Shot noise caused Channel thermal noise and flicker noise The second bias resistor R d Thermal noise exists The feedback resistor R f Thermal noise exists Wherein: the shot noise The value is 2qi d df, the thermal noise The value is 4KT / R b df, the shot noise The value is 2qi d df, the thermal noise The value is 4KT / R f df, the flicker noise The value is K F / (C g f)df, the thermal noise The value is The thermal noise of the channel The value is 8KT / (3g) m )df.

[0123] In practice, all noise sources are mapped to the input terminal of the amplification unit (the gate of the junction field-effect transistor).

[0124] Specifically, the shot noise thermal noise shot noise and the thermal noise All of these are current noise mapped to the input terminal of the amplification unit. The corresponding noise source can be equivalent to a current source. Therefore, during AC coupling, the noise signal output by the aforementioned equivalent current source... for:

[0125]

[0126] Where ω represents the radian frequency, and its value is equal to 2*i*.

[0127] The flicker noise The thermal noise of the channel and the thermal noise The voltage noise mapped to the input of the amplification unit can be equivalently represented by a voltage source. Therefore, during AC coupling, the noise signal output by the aforementioned equivalent voltage source... for:

[0128]

[0129] Among them, C in2 This represents the equivalent capacitance from the gate of the junction field-effect transistor to the detector terminal, and its value is:

[0130] C in2 =C g +C s2 +C X (C d +C s1 ) / (C X +C d +C s1 (13)

[0131] During AC coupling, the total noise signal output from the output terminal of the amplification unit (the output terminal of the operational amplifier) ​​is... for:

[0132]

[0133] Similar to the previous example, in order to obtain quantifiable noise of the detection signal, a CR-RC shaping network can be connected to the output of the particle radiation detection device. This network can be coupled to the output of the operational amplifier and is suitable for converting the noise signal into a shaped signal. Based on the processing of the shaped signal, the noise of the detection signal can be quantified.

[0134] As an optional example, the noise signal output by the amplification unit The signal is transmitted to the CR-RC forming network, processed by the CR-RC forming network, and then output as a forming signal. Its value is:

[0135]

[0136] During AC coupling, the corresponding ENC AC and FWHM AC They are respectively:

[0137]

[0138] FWHM AC =2.35W / ENC AC (17)

[0139] At the same time, through the output signal With forming signal The ratio can also be used to obtain the signal-to-noise ratio (SNR) of the probe signal during AC coupling. AC The signal-to-noise ratio (SNR) of the detection signal AC for:

[0140]

[0141] To enable those skilled in the art to better understand, the following specific examples illustrate the correlation between the coupling method between the detection module and the readout module and the size of the detection module.

[0142] As an optional example, continue to refer to Figure 2A and Figure 2B The structure of the particle radiation detection device is shown, and a comparative analysis is conducted on particle radiation detection devices equipped with a first detector and a second detector under both DC coupling and AC coupling conditions. As a specific example, the main parameters of the particle radiation detection device are listed in the following table:

[0143] value <![CDATA[4mm 2 ]]> 500um <![CDATA[1×10 -9 A]]> 1pF

[0144] Table 1 Parameters of the first detector

[0145] value <![CDATA[200mm 2 ]]> 50um <![CDATA[50×10 -9 A]]> 500pF

[0146] Table 2 Parameters of the second detector

[0147] For two particle radiation detection devices using the same coupling method, all parameters are identical except for the detector parameters; for two particle radiation detection devices using the same detector, all parameters are identical except for the presence or absence of a coupling capacitor. As a specific example, the main parameters of the particle radiation detection device other than the detector are listed below:

[0148] value <![CDATA[10×10 -9 A]]> 8pF <![CDATA[7×10 -3 S]]> <![CDATA[5×10 -28 J]]> <![CDATA[1.380649×10 -23 J / K]]>

[0149] Table 3 Parameters of Junction Field-Effect Transistors

[0150] value 300K(27℃) 1.5KΩ 100MΩ 3pF parameter <![CDATA[R b ]]> <![CDATA[C x ]]> <![CDATA[A0]]> A value 100MΩ 0.01uF 38*2.718 <![CDATA[10 5 ]]>

[0151] Table 4 Other parameters

[0152] Based on the parameters in Tables 3 and 4, the first and second thickness thresholds are preset to 100 μm, and the first and second area thresholds are preset to 10 mm. 2 .

[0153] Configure the particle radiation detection device according to the following four examples:

[0154] Example A1: The particle radiation detection device uses AC coupling and employs a first detector. The first detector and the coupling capacitor are integrated. In this case, the stray capacitance C exists on the line between the first detector and the coupling capacitor. s1 The stray capacitance C between the first detector and the junction field-effect transistor can be ignored. s The equivalent stray capacitance C on the line between the coupling capacitor and the junction field-effect transistor is... s2 .

[0155] Example A2: The particle radiation detection device uses AC coupling and a second detector. In this case, the stray capacitance C present on the line between the second detector and the coupling capacitor... s1 The stray capacitance C between the second detector and the junction field-effect transistor can be ignored. s The equivalent stray capacitance C on the line between the coupling capacitor and the junction field-effect transistor is... s2 .

[0156] Example B1: The particle radiation detection device uses DC coupling and employs a first detector.

[0157] Example B2: The particle radiation detection device uses DC coupling and employs a second detector.

[0158] Figure 4A The FWHM shows a particle radiation detection device with the first detector set in an AC-coupled configuration. AC Curve 4a shows the relationship between stray capacitance and stray capacitance.

[0159] Figure 4B The FWHM shows a particle radiation detection device with the first detector set in a DC-coupled configuration. DC With stray capacitance C s The corresponding relationship curve 4b.

[0160] Figure 5A FWHM illustrates a particle radiation detection device with a second detector configured in AC coupling conditions. AC The corresponding curve 5a shows the relationship between stray capacitance and the capacitance.

[0161] Figure 5B FWHM illustrates a particle radiation detection device with a second detector configured in DC coupling conditions. DC With stray capacitance C s The corresponding relationship curve between them is shown in curve 5b.

[0162] Reference Figure 4A , Figure 4B , Figure 5A and Figure 5B In the four examples described above, the FWHM of each particle radiation detection device increases with the stray capacitance C. s The stray capacitance C increases with the increase of [something]. Considering noise reduction, in specific implementations, the stray capacitance C can be reduced. s The value of .

[0163] Through the formula (FWHM) AC -FWHM DC ), Figure 4C Show Figure 4A and Figure 4B The corresponding curve 4c shows the difference between the FWHM and stray capacitance of the particle radiation detection device with the first detector under AC coupling and DC coupling conditions.

[0164] Through the formula (FWHM) AC -FWHM DC ) / FWHM AC , Figure 4D It shows Figure 4A and Figure 4B The corresponding curve 4d shows the relative difference between FWHM and stray capacitance of the particle radiation detection device with the first detector under AC coupling and DC coupling conditions.

[0165] Reference Figure 4C and Figure 4D When the stray capacitance C between the first detector and the junction field-effect transistor s When the stray capacitance is less than or equal to 30 pF (i.e., the aforementioned preset threshold), the values ​​of curves 4C and 4d are not less than 0, and the corresponding noise during AC coupling is relatively large. For the same stray capacitance value, the noise value corresponding to AC coupling is the preset noise threshold at this time. Considering noise reduction, in specific implementations, for particle radiation detection devices equipped with the first detector, when the stray capacitance is less than or equal to the preset threshold, the first detector and the junction field-effect transistor can be set to DC coupling.

[0166] When the stray capacitance C between the first detector and the junction field-effect transistor s When the value is greater than 30 pF (i.e., the aforementioned preset threshold), the values ​​of curves 4c and 4d are less than 0, and the noise corresponding to DC coupling is relatively large. For the same stray capacitance value, the noise value corresponding to DC coupling is the preset noise threshold at this time. Considering the need to reduce noise, in specific implementations, for particle radiation detection devices equipped with the first detector, the first detector and the junction field-effect transistor can be set to AC coupling.

[0167] Through the formula (FWHM) AC -WHM DC ), Figure 5C It shows Figure 5A and Figure 5B The corresponding particle radiation detection device of the second detector is set with the difference curves between FWHM and stray capacitance under AC coupling and DC coupling conditions, 5c.

[0168] Through the formula (FWHM) AC -FWHM DC ) / FWHM AC , Figure 5D It shows Figure 5A and Figure 5B The corresponding relative difference curves 5d between FWHM and stray capacitance of the particle radiation detection device of the second detector under AC coupling and DC coupling conditions are shown.

[0169] Reference Figure 5C and Figure 5D The values ​​of curves 5c and 5d are always less than 0, and the corresponding noise during AC coupling is always relatively high. For the same stray capacitance value, the noise value corresponding to AC coupling is the preset noise threshold at this time. Considering noise reduction, in specific implementations, for particle radiation detection devices with the second detector, the second detector and the junction field-effect transistor can be set to DC coupling.

[0170] Figure 6The output voltage V of the particle radiation detection device with the first detector set is shown under AC coupling conditions. outAC With stray capacitance C s The corresponding relationship curve 6a, and the output voltage V under DC coupling conditions. outDC With stray capacitance C s The corresponding relationship curve 6b between them.

[0171] Figure 7 The output voltage V of the particle radiation detection device with a second detector in AC coupling condition is shown. outAC With stray capacitance C s The corresponding relationship curve 7a, and the output voltage V under DC coupling conditions. outDC With stray capacitance C s The corresponding relationship curve between them is shown in curve 7b.

[0172] Reference Figure 6 and Figure 7 In the four examples described above, the output voltage V of each particle radiation detection device... out All with stray capacitance C s The stray capacitance C increases with the increase of [something]. Considering noise reduction, in specific implementations, the stray capacitance C can be reduced. s The value of . Meanwhile, the output voltage of each detector is relatively small under AC coupling because, due to the presence of the coupling capacitor, some charge signal is distributed on the stray capacitor; the larger the stray capacitor, the more charge signal is distributed. Considering a larger output voltage, the detector and the junction field-effect transistor can be set to DC coupling.

[0173] Figure 8 The SNR of the detection signal of the particle radiation detection device with the first detector set up is shown under AC coupling conditions. AC With stray capacitance C s The corresponding relationship curve 8a, and the SNR of the detection signal under DC coupling conditions. DC With stray capacitance C s The corresponding relationship curve between them is shown in curve 8b.

[0174] Figure 9 The SNR of the detection signal of the particle radiation detection device with a second detector in AC coupling condition is shown. AC With stray capacitance C s The corresponding relationship curve 9a, and the SNR of the detection signal under DC coupling. DC With stray capacitance C s The corresponding relationship curve between them is shown in curve 9b.

[0175] Reference Figure 8and Figure 9 In the four examples described above, the SNR of the detection signal of each particle radiation detection device decreases with the increase of the corresponding stray capacitance. Considering the need to increase the SNR of the detection signal, in specific implementations, the stray capacitance C can be reduced. s The value of .

[0176] Through the formula (SNR) AC -SNR DC ) / SNR AC , Figure 10 It shows Figure 8 and Figure 9 The corresponding curves 10a show the relative differences between the SNR and stray capacitance of the particle radiation detection device with the first detector in AC coupling and DC coupling, and 10b show the relative differences between the SNR and stray capacitance of the particle radiation detection device with the second detector in AC coupling and DC coupling.

[0177] Reference Figure 10 In a particle radiation detection device with a first detector and a second detector, the relative difference in the SNR of the corresponding detection signals decreases with increasing stray capacitance under both AC and DC coupling conditions. Furthermore, regardless of whether the relative difference curve is 10a or 10b, the relative difference in SNR is less than 0, meaning the SNR under DC coupling is... DC The signal density (SNR) of the particle radiation detection device is relatively high. In specific implementations, when considering the SNR of the detection signal of the particle radiation detection device, the detector and the junction field-effect transistor can be set to DC coupling.

[0178] It should be noted that the first thickness threshold, the second thickness threshold, the first area threshold, the second area threshold, and the preset threshold are all determined by the parameters of other devices in the particle radiation detection device besides the detector.

[0179] It is understood that the first thickness threshold and the second thickness threshold may be equal or unequal, and the first area threshold and the second area threshold may be equal or unequal; the embodiments of the present invention do not impose any restrictions on them.

[0180] It should be noted that the terms "first" and "second" in the embodiments of this specification are used only for distinguishing descriptions and are not used to indicate the order, priority or importance of the corresponding concepts.

[0181] While the embodiments disclosed in this specification are as described above, the present invention is not limited thereto. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the invention; therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

Claims

1. A particle radiation detection device, characterized in that, include: The detection module is suitable for detecting particle radiation and converting it into an initial electrical signal; The readout module, coupled to the detection module, is adapted to output a detection signal based on the initial electrical signal; The coupling method between the detection module and the readout module is determined based on the size of the detection module to ensure that the noise of the detection signal is less than a preset noise threshold. The detection module includes a detector, which is coupled to an external power supply and the input terminal of the readout module, respectively, and is suitable for detecting particle radiation and converting it into an initial electrical signal. Whether the coupling method between the detector and the readout module is DC coupling or AC coupling is determined based on the thickness and area of ​​the detector.

2. The detection device according to claim 1, characterized in that, When the thickness of the detector is less than a preset first thickness threshold and the area is greater than a preset first area threshold, the detector is DC coupled to the readout module.

3. The detection device according to claim 1, characterized in that, When the thickness of the detector is greater than a preset second thickness threshold and the area is less than a preset second area threshold, the coupling mode between the detector and the readout module is determined based on the stray capacitance between the detector and the readout module.

4. The detection device according to claim 3, characterized in that, When the stray capacitance is greater than a preset threshold, the detector is AC coupled to the readout module; When the stray capacitance is less than or equal to the preset threshold, the detector is DC coupled to the readout module.

5. The detection device according to claim 4, characterized in that, The detector is AC-coupled to the readout module, and the detection device further includes: A coupling module, coupled between the detection module and the readout module, is adapted to block the DC signal in the initial electrical signal and allow the AC signal in the initial electrical signal to pass through.

6. The detection device according to claim 1, characterized in that, The readout module includes: An amplification unit, coupled to the detection module, is adapted to amplify the initial electrical signal and output the detection signal; A feedback unit, connected in parallel with the amplification unit, is adapted to feed back the detection signal output by the amplification unit to the input terminal of the amplification unit.

7. The detection device according to claim 6, characterized in that, The amplification unit includes: An operational amplifier, coupled to the detection module, is adapted to output the detection signal; The junction field-effect transistor has its gate coupled to the output terminal of the detection module, its source grounded, and its drain coupled to the external power supply and the input terminal of the operational amplifier, respectively.

8. The detection device according to claim 6, characterized in that, The feedback unit includes: The feedback resistor is connected in parallel with the amplification unit; The feedback capacitor is connected in parallel with the amplification unit.

Images