CN113238277B - Infrared excitation type high-resolution tellurium-zinc-cadmium nuclear radiation detection system - Google Patents

Abstract

The invention provides an infrared excitation type high-resolution cadmium zinc telluride nuclear radiation detection system which improves the carrier transmission efficiency of a cadmium zinc telluride crystal material in an infrared irradiation external excitation mode, so that the current carrier in the cadmium zinc telluride detector can be excited to carry out high-efficiency transmission by irradiating the weakest electric field region in the cadmium zinc telluride detector by using the sub-forbidden band infrared in a specific wavelength range under the condition of not improving the crystal growth and the pulse signal correction of the cadmium zinc telluride detector and improving the electrode structure design of the cadmium zinc telluride detector, thereby furthest improving the detection sensitivity and the energy resolution of the cadmium zinc telluride detector, reducing the cost of the cadmium zinc telluride detector and improving the energy resolution of the cadmium zinc telluride detector.

Description

Infrared excitation high-resolution cadmium zinc telluride nuclear radiation detection system

technical field

The invention relates to the technical field of nuclear radiation detection, in particular to an infrared excitation type high-resolution cadmium zinc telluride nuclear radiation detection system.

Background technique

Nuclear radiation rays such as X-rays and gamma rays are widely used as detection rays in space science, energy science, materials science and biomedicine. At present, cadmium zinc telluride (CdZnTe) semiconductors have been widely used to make nuclear radiation ray detectors due to their excellent material properties, but CdZnTe detectors still have defects in the carrier transport characteristics, which makes it impossible to greatly improve The energy resolution of the cadmium zinc telluride detector for detecting nuclear radiation rays. The existing technology can improve the detection sensitivity and energy of the CdZnTe detector by improving the growth characteristics of the CdZnTe detector, performing pulse signal correction processing on the CdZnTe detector, and improving the electrode structure design of the CdZnTe detector. However, the above method not only has a complicated implementation process, but also requires a large investment, which is not conducive to reducing the production cost of the cadmium zinc telluride detector and expanding the application range of the cadmium zinc telluride detector.

SUMMARY OF THE INVENTION

In view of the defects in the prior art, the present invention provides an infrared excitation type high-resolution cadmium zinc telluride nuclear radiation detection system, which comprises an infrared excitation light source, a nuclear radiation emission source, a cadmium zinc telluride detector, a preamplifier and a spectrometer; The infrared excitation light source is used to emit at least one beam of infrared light, and at least one beam of infrared light is irradiated on the detection surface of the cadmium zinc telluride detector at a corresponding inclination angle; the nuclear radiation emission source is used to emit nuclear radiation rays, the nuclear radiation The radiation ray is vertically irradiated on the detection surface, which is used for the energy spectrum calibration of the CdZnTe detector; the preamplifier is connected with the CdZnTe detector, and is used for amplifying the induced charge on the anode of the CdZnTe detector. , to obtain an exponentially decaying voltage pulse signal proportional to the ray energy; the spectrometer is connected to the preamplifier, which is used to analyze and process the signal output by the preamplifier; it can be seen that the infrared excitation type high-resolution zinc telluride The cadmium nuclear radiation detection system improves the carrier transmission efficiency of the cadmium zinc telluride crystal material through the external excitation method of infrared irradiation, so that the crystal growth improvement, pulse signal correction processing and tellurium improvement of the cadmium zinc telluride detector are not required. In the case of the electrode structure design of the zinc-cadmium detector, the use of sub-gap infrared in a specific wavelength range to irradiate the region with the weakest electric field in the cadmium zinc telluride detector can excite the carriers in the cadmium zinc telluride detector for efficient transport, so that the This maximizes the detection sensitivity and energy resolution of the CdZnTe detector, thereby reducing the cost of the CdZnTe detector and improving the energy resolution of the CdZnTe detector.

The invention provides an infrared excitation type high-resolution cadmium zinc telluride nuclear radiation detection system, which is characterized in that it comprises an infrared excitation light source, a nuclear radiation emission source, a cadmium zinc telluride detector, a preamplifier and a spectrometer; wherein,

The infrared excitation light source is used to emit at least one beam of infrared light, and the at least one beam of infrared light is irradiated on the detection surface of the cadmium zinc telluride detector at a corresponding inclination angle;

The nuclear radiation emission source is used for emitting nuclear radiation rays, and the nuclear radiation rays are vertically irradiated to the detection surface for energy spectrum calibration of the cadmium zinc telluride detector;

the preamplifier is connected to the cadmium zinc telluride detector, and is used to amplify the anode-induced charge of the cadmium zinc telluride detector to obtain an exponentially decaying voltage pulse signal proportional to the ray energy;

The spectrometer is connected to the preamplifier, and is used for analyzing and processing the signal output by the preamplifier;

Further, the infrared excitation light source includes an infrared LED, a light intensity adjuster, an infrared filter and an infrared light irradiation adjuster; wherein,

The light intensity adjuster is connected to the infrared LED, and is used for adjusting the intensity of the infrared light emitted by the infrared LED;

The infrared filter is arranged on the transmission path of the infrared light emitted by the infrared LED, and is used for filtering the infrared light, so as to obtain infrared light satisfying a preset wavelength range;

The infrared light irradiation adjuster is used for converting infrared light satisfying a preset wavelength range into at least one beam of infrared light, and adjusting the inclination angle at which the at least one beam of infrared light irradiates the detection surface;

Further, the light intensity regulator includes a sliding resistor and a power supply;

the power supply is connected to the infrared LED through the slip resistor;

The sliding resistor is used to change the power supply current output by the power supply to the infrared LED, so as to adjust the intensity of the infrared light emitted by the infrared LED;

Further, the infrared filter is a narrowband infrared filter;

The narrow-band infrared filter is used for filtering the infrared light, so as to obtain infrared light with a wavelength range of 800nm-1200nm and a spectral band width of 30nm-40nm;

Further, the infrared light irradiation adjuster includes an infrared light beam splitter and an infrared light redirector; wherein,

The infrared beam splitter is used for condensing and/or beam splitting the infrared light output by the infrared filter, so as to obtain at least one beam of infrared light;

The infrared light redirector is used for scanning and deflecting the at least one beam of infrared light, so as to change the transmission direction of the at least one beam of infrared light, so that the at least one beam of infrared light is irradiated to the the detection surface of the cadmium zinc telluride detector;

Further, the inclination angle is 30°-75°;

or,

The infrared excitation light source includes an infrared light shielding box, and the infrared light shielding box is used to block infrared light from leaking to the external environment;

or,

The nuclear radiation emission source includes a lead shielding box, and the lead shielding box is used to block the leakage of nuclear radiation rays to the external environment;

or,

the cadmium zinc telluride detector and the preamplifier are placed together in the front-end shielding box;

or,

The cadmium zinc telluride detector is a hemispherical cadmium zinc telluride detector;

Further, the cathode of the cadmium zinc telluride detector is grounded;

The anode of the cadmium zinc telluride detector is connected to the input end of the preamplifier by AC coupling;

The anode of the cadmium zinc telluride detector is also connected with the power supply;

Further, the preamplifier is a charge sensitive preamplifier;

The charge-sensitive preamplifier is used for amplifying the charge induced by the anode of the cadmium zinc telluride detector to obtain an exponentially decaying voltage pulse signal proportional to the ray energy;

Further, the spectrometer includes a linear amplifier and a multi-channel analyzer;

The input end of the linear amplifier is connected to the charge-sensitive preamplifier, for shaping the exponentially decaying voltage pulse signal into a Gaussian pulse signal, and linearly amplifying the Gaussian pulse signal;

The input end of the multi-channel analyzer is connected to the output end of the linear amplifier for analyzing the linearly amplified Gaussian pulse signal;

Further, the output end of the linear amplifier is also connected with an oscilloscope;

The output end of the multi-channel analyzer is also connected with a PC, and the PC is used for calibrating the corresponding energy spectrum of the nuclear radiation ray according to the analysis result of the multi-channel analyzer.

Compared with the prior art, the infrared excitation type high-resolution cadmium zinc telluride nuclear radiation detection system includes an infrared excitation light source, a nuclear radiation emission source, a cadmium zinc telluride detector, a preamplifier and a spectrometer; In order to emit at least one beam of infrared light, at least one beam of infrared light is irradiated on the detection surface of the cadmium zinc telluride detector at a corresponding inclination angle; the nuclear radiation emission source is used to emit nuclear radiation rays, and the nuclear radiation rays are irradiated vertically to the detection surface of the cadmium zinc telluride detector; The detection surface is used for energy spectrum calibration of the CdZnTe detector; the preamplifier is connected to the CdZnTe detector, and is used for amplifying the induced charge on the anode of the CdZnTe detector to obtain the ray energy proportional exponential decay voltage pulse signal; the spectrometer is connected to the preamplifier, and is used for analyzing and processing the signal output by the preamplifier; it can be seen that the infrared excitation type high-resolution cadmium zinc telluride nuclear radiation detection system The carrier transmission efficiency of the CdZnTe crystal material is improved by the external excitation method of infrared irradiation, so that the crystal growth improvement, the pulse signal correction processing and the improvement of the CdZnTe detector are not required for the CdZnTe detector. In the case of electrode structure design, the use of sub-gap infrared in a specific wavelength range to irradiate the region with the weakest electric field in the CdZnTe detector can excite the carriers in the CdZnTe detector for efficient transport, thereby maximizing the The detection sensitivity and energy resolution of the cadmium zinc telluride detector, thereby reducing the cost of the cadmium zinc telluride detector and improving the energy resolution of the cadmium zinc telluride detector.

Other features and advantages of the present invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description, claims, and drawings.

The technical solutions of the present invention will be further described in detail below through the accompanying drawings and embodiments.

Description of drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained according to these drawings without creative efforts.

1 is a schematic structural diagram of an infrared excitation type high-resolution cadmium zinc telluride nuclear radiation detection system provided by the present invention.

FIG. 2 is a schematic diagram of the irradiation mode of infrared rays and rays in the infrared excitation type high-resolution cadmium zinc telluride nuclear radiation detection system provided by the present invention.

Reference numerals: 1. Cadmium zinc telluride detector; 2. Preamplifier; 3. Spectrometer; 4. Oscilloscope; 5. PC; 6. Front-end shielding box; 7. Nuclear radiation emission source; 8. Lead shielding Box; 9. Infrared LED; 10. Infrared light shielding box; 11. Infrared filter; 12. Power supply; 13. Sliding resistor.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

Referring to FIG. 1 , it is a schematic structural diagram of an infrared excitation type high-resolution cadmium zinc telluride nuclear radiation detection system provided by an embodiment of the present invention. The infrared excitation type high-resolution cadmium zinc telluride nuclear radiation detection system includes an infrared excitation light source, a nuclear radiation emission source 7, a cadmium zinc telluride detector 1, a preamplifier 2 and a spectrometer 3; wherein,

The infrared excitation light source is used to emit at least one beam of infrared light, and the at least one beam of infrared light irradiates the detection surface of the cadmium zinc telluride detector 1 at a corresponding inclination angle;

The nuclear radiation emission source 7 is used for emitting nuclear radiation rays, and the nuclear radiation rays are vertically irradiated on the detection surface for energy spectrum calibration of the cadmium zinc telluride detector;

The preamplifier 2 is connected to the cadmium zinc telluride detector 1, and is used to amplify the anode-induced charge of the cadmium zinc telluride detector 1 to obtain an exponentially decaying voltage pulse signal proportional to the ray energy;

The spectrometer 3 is connected to the preamplifier 2 and is used for analyzing and processing the signal output by the preamplifier 2 .

The beneficial effects of the above technical solutions are: the infrared excitation type high-resolution cadmium zinc telluride nuclear radiation detection system improves the carrier transmission efficiency of the cadmium zinc telluride crystal material through the external excitation mode of infrared irradiation, so that it can be The situation of crystal growth improvement, pulse signal correction processing and electrode structure design improvement of the CdZnTe detector, using sub-gap infrared in a specific wavelength range to illuminate the region with the weakest electric field in the CdZnTe detector, It can excite the carriers in the CdZnTe detector for efficient transport, thereby maximizing the detection sensitivity and energy resolution of the CdZnTe detector, thereby reducing the cost of the CdZnTe detector and improving the detection of the CdZnTe detector. energy resolution of the device.

Preferably, the infrared excitation light source includes an infrared LED 9, a light intensity adjuster, an infrared filter 11 and an infrared light irradiation adjuster; wherein,

The light intensity adjuster is connected with the infrared LED9, and is used to adjust the intensity of the infrared light emitted by the infrared LED9;

The infrared filter 11 is arranged on the transmission path of the infrared light emitted by the infrared LED 9, and is used for filtering the infrared light to obtain infrared light satisfying a preset wavelength range;

The infrared light irradiation adjuster is used for converting infrared light satisfying a preset wavelength range into at least one beam of infrared light, and adjusting the inclination angle at which the at least one beam of infrared light irradiates the detection surface.

The beneficial effects of the above technical solutions are: because the intensity of the infrared light irradiated on the cadmium zinc telluride detector will affect the excitation in the cadmium zinc telluride crystal and improve the degree of excitation of the carrier transmission efficiency, generally speaking, the intensity of the infrared light The larger the value is, the better the carrier transport efficiency in the CdZnTe crystal can be improved, but when the intensity of the infrared light is too large, the energy spectrum characteristics will be reduced due to the generation of photogenerated carriers. In addition, since the carrier transition of CdZnTe crystal has a certain forbidden band width, it is required that the infrared light irradiated on the CdZnTe crystal must meet a certain wavelength range in order to make the carrier transition in the CdZnTe crystal. , and the infrared light emitted by infrared LEDs has a wider spectrum. The infrared filter is used to filter the infrared light and only allow the transmission of infrared light in the preset wavelength range, which can maximize the exposure to the detection surface of the cadmium zinc telluride detector. The infrared light on it effectively excites the carriers to transition.

Since the electric field strength at the four corners of the detection surface of the CdZnTe detector is the weakest, the carriers at the four corners are correspondingly more easily captured, so the infrared light irradiation adjuster is used to satisfy the preset The infrared light in the wavelength range is converted into at least one beam of infrared light, and the inclination angle at which the at least one beam of infrared light is irradiated to the detection surface can be adjusted to ensure that the four corners can be excited by the infrared light to the greatest extent and improve the load carrying capacity. The carrier's transport efficiency.

Preferably, the light intensity adjuster includes a sliding resistor 13 and a power source 12;

The power supply 12 is connected to the infrared LED 9 through the sliding resistor 13;

The sliding resistor 13 is used to change the power supply current output by the power supply 12 to the infrared LED 9 , so as to adjust the intensity of the infrared light emitted by the infrared LED 9 .

The beneficial effects of the above technical solutions are: because the infrared LED is a current-excited light-emitting element, the power supply and the infrared LED are connected through a sliding resistor, which can easily change the resistance value of the sliding resistor connected to the circuit according to actual needs, thereby changing the power supply. The power supply current output to the infrared LED, so as to adjust the intensity of the infrared light actually emitted by the infrared LED. The power source may be, but not limited to, different types of DC power sources such as dry cells or accumulators.

Preferably, the infrared filter 11 is a narrowband infrared filter;

The narrow-band infrared filter is used to filter the infrared light to obtain infrared light with a wavelength range of 800nm-1200nm and a spectral band width of 30nm-40nm.

The beneficial effects of the above technical solutions are: the infrared filter is set as a narrow-band infrared filter, which can effectively bandpass and filter the infrared light emitted by the infrared LED, thereby ensuring that only infrared light satisfying the preset wavelength range can transmit through the infrared filter. Narrowband infrared filter. In addition, the wavelength of the infrared light filtered by the narrow-band infrared filter may preferably be 940 nm, so that the wavelength of the infrared light can be more matched with the forbidden band width of the cadmium zinc telluride crystal, and the spectral band of the infrared light obtained after filtering The width is preferably 35 nm, which can improve the excitation efficiency of infrared light.

Preferably, the infrared light irradiation adjuster includes an infrared light beam splitter and an infrared light redirector; wherein,

The infrared beam splitter is used for condensing and/or beam splitting the infrared light output by the infrared filter 11, thereby obtaining at least one beam of infrared light;

The infrared light redirector is used for scanning and deflecting the at least one beam of infrared light, so as to change the transmission direction of the at least one beam of infrared light, so that the at least one beam of infrared light is irradiated to the cadmium zinc telluride detector at a corresponding inclination angle on the detection surface of device 1.

The beneficial effects of the above technical solutions are: the infrared beam splitter can include a focusing and collimating lens group and at least one semi-transparent mirror, and the focusing and collimating lens group is used for focusing and collimating the infrared light, thereby improving the infrared light The convergence efficiency of the semi-transparent mirror is used to divide the infrared light into a beam of reflected infrared light and a beam of transmitted infrared light, so that at least one beam of infrared light can be obtained, and the more the number of semi-transparent mirrors, The number of infrared beams obtained after splitting is also greater.

The infrared light redirector may include a scanning galvanometer and a driver, and the driver is used to drive the scanning galvanometer to rotate, so that the scanning galvanometer can irradiate each beam of infrared light to the cadmium zinc telluride detector at a preset inclination angle In the four corner areas of the detection surface of the detector, the controllability of the irradiation angle of the infrared beam and the range of the irradiation area is greatly improved.

Since the detection surface of the CdZnTe detector is rectangular, in order to accurately control the scanning galvanometer to reflect and deflect the infrared light, a rectangular vertex of the detection surface of the CdZnTe detector is taken as the origin, and a rectangular side passing through the origin is located. The line passing through the origin is the x-axis, the line passing through the origin of the other rectangular side is the y-axis, and the line passing through the origin and perpendicular to the detection surface is the z-axis to construct a space Cartesian coordinate system, according to the space Cartesian coordinate system to obtain CdZnTe The normal vector corresponding to the detection surface of the detector is (0, 0, 1), and the coordinates of the four rectangular vertices of the detection surface of the CdZnTe detector are (0, 0, 0), (X, 0 respectively. , 0), (0, Y, 0), (X, Y, 0); and the infrared light is reflected and deflected by the scanning galvanometer, and the unit vector corresponding to the propagation direction of each reflected and deflected infrared light That is (X _a , Y _a , Z _a ), wherein (X _a , Y _a , Z _a ) represent the unit vector corresponding to the transmission direction of the a-th infrared light. First, the unit vector corresponding to each infrared light is analyzed, and the infrared light that can reach the detection surface after being reflected and deflected by the scanning galvanometer is selected; then the distance between the propagation direction of the selected infrared light and the normal direction of the detection surface is calculated. If the calculated angle is within the preset angle range, the infrared light will no longer be reflected and deflected; if the calculated angle is not within the preset angle range, then calculate the angle that the scanning galvanometer needs to deflect. The specific process includes:

Step S1, using the following formula (1), according to the unit vector corresponding to each infrared light and the coordinates of the four rectangular vertices of the detection surface, filter out the infrared light that can reach the detection surface after being reflected and deflected by the scanning galvanometer,

In the above formula (1), A _a represents the screening value of the a-th infrared light. When A _a = 0, it means that the a-th infrared light cannot reach the detection surface after being reflected and deflected by the scanning galvanometer. When A _a ≠ 0 When , it means that the a-th infrared light can reach the detection surface after being reflected and deflected by the scanning galvanometer _.

Through the above formula (1), filter out all the infrared lights with A _a ≠ 0, sort them from small to large according to the size of A _a , and renumber all the infrared lights with A _a ≠ 0 according to the sorted order And get (X _i ,Y _i ,Z _i ) of each infrared light, where (X _i ,Y _i ,Z _i )represents the infrared light after screening and processing according to its corresponding A _a value sorted from small to large unit vector of the i-th infrared light;

Step S2, using the following formula (2), according to the normal vector of the detection surface and the unit vector (X _i , Y _i , Z _i ) of each infrared light obtained after screening and sorting, calculate each selected infrared light. The angle between the propagation direction of the light and the normal direction of the detection surface,

In the above formula (2), θ _i represents the angle between the propagation direction of the i-th infrared light after screening and sorting and the normal direction of the detection surface;

Compare the included angle θ _i with the preset angle range, where the preset angle range can be but is not limited to 30°-75°, if the included angle θ _i is within the preset angle range, the infrared The light is reflected and deflected; if the included angle θ _i is not within the preset angle range, the following step S3 is used to calculate the deflection angle that the infrared light needs to continue to deflect;

Step S3, using the following formula (3), it is determined that when the included angle θ _i is not within the preset angle range, the angle that the scanning galvanometer needs to be deflected is calculated,

表示求取括号内的最小值，n表示A_a≠0对应的所有红外光的总数，α_min表示预设角度范围对应的最小角度值，α_max表示预设角度范围对应的最大角度值，||表示绝对值符号；In the above formula (3), θ represents the angle at which the scanning galvanometer needs to be deflected,

Represents the minimum value in the brackets, n represents the total number of all infrared lights corresponding to A _a ≠ 0, α _min represents the minimum angle value corresponding to the preset angle range, α _max represents the maximum angle value corresponding to the preset angle range, | | represents the absolute value symbol;

Then, the deflection angle θ of the scanning galvanometer is controlled to ensure that all infrared light corresponding to A _a ≠ 0 can be accurately reflected to the detection surface by the scanning galvanometer.

The beneficial effect of the above technical solution is: using the above formula (1), the infrared light that can reach the detection surface after being reflected and deflected by the scanning galvanometer is screened, so that unnecessary infrared light reflection analysis can be reduced, and the calculation and analysis efficiency of the system can be improved; Then use the above formula (2) to calculate the angle between the propagation direction of each infrared light screened out and the normal direction of the detection surface, so as to facilitate the accurate control of the scanning galvanometer according to the calculation result; finally use the above formula (3) ), calculate the angle that the scanning galvanometer needs to deflect, so as to drive the scanning galvanometer to deflect the corresponding angle, so as to ensure that all infrared light can be accurately reflected by the scanning galvanometer to the detection surface and improve the utilization efficiency of infrared light.

Preferably, the inclination angle is 30°-75°, wherein the inclination angle can be 45°, which can ensure that the infrared light can comprehensively cover the four corners of the detection surface of the cadmium zinc telluride detector.

Preferably, the infrared excitation light source includes an infrared light shielding box 10, and the infrared light shielding box 10 is used to block the leakage of infrared light to the external environment. Infrared light blocking shielding efficiency.

Preferably, the nuclear radiation emitting source 7 includes a lead shielding box 8, and the lead shielding box 8 is used to block the leakage of nuclear radiation rays to the external environment, and the nuclear radiation emitting source 7 can be, but is not limited to, a Cs ¹³⁷ radiation source;

Preferably, the cadmium zinc telluride detector 1 and the preamplifier 2 are placed together in a front-end shielding box 6, and the front-end shielding box 6 may be but not limited to an aluminum shielding box, which can effectively avoid the cadmium zinc telluride detector 1 and the preamplifier 2 suffers from EMI.

Preferably, the cadmium zinc telluride detector 1 is a hemispherical cadmium zinc telluride detector 1 .

Preferably, the cathode of the cadmium zinc telluride detector 1 is grounded;

The anode of the cadmium zinc telluride detector 1 is connected to the input end of the preamplifier 2 by AC coupling;

The anode of the cadmium zinc telluride detector 1 is also connected to the power supply.

The beneficial effects of the above technical solutions are as follows: the cathode of the cadmium zinc telluride detector is grounded and the anode is connected to the input end of the preamplifier in an AC coupling manner, which can ensure that the anode-induced charge signal signal of the cadmium zinc telluride detector can be free of charge. Distortionally transmitted to the preamplifier for corresponding processing, and output an exponentially decaying voltage pulse signal. The power supply can be, but is not limited to, a DC power supply, so that the cadmium zinc telluride detector can be supplied with voltage regulation and constant current.

Preferably, the preamplifier 2 is a charge sensitive preamplifier 2;

The charge sensitive preamplifier 2 is used for amplifying the charge induced by the anode of the cadmium zinc telluride detector 1 to obtain an exponentially decaying voltage pulse signal proportional to the ray energy.

The beneficial effect of the above technical scheme is that the charge signal induced by the anode of the cadmium zinc telluride detector can be converted into an exponentially decaying voltage pulse signal by using the charge sensitive preamplifier, so as to facilitate subsequent reliable signal analysis and processing.

Preferably, the spectrometer 3 includes a linear amplifier and a multi-channel analyzer;

The input end of the linear amplifier is connected to the charge-sensitive preamplifier 2 for shaping the exponentially decaying voltage pulse signal into a Gaussian pulse signal and linearly amplifying the Gaussian pulse signal;

The input end of the multi-channel analyzer is connected with the output end of the linear amplifier for analyzing the linearly amplified Gaussian pulse signal.

The beneficial effects of the above technical solutions are: the spectrometer uses a linear amplifier to perform Gaussian shaping on an exponentially decaying voltage pulse signal to obtain a Gaussian pulse signal, and performs linear amplification, which can improve the fidelity of the signal; and the multi-channel analyzer can be used. Effectively perform statistical analysis on the linearly amplified voltage signal to obtain the corresponding nuclear radiation ray energy spectrum information.

Preferably, an oscilloscope 4 is also connected to the output end of the linear amplifier, and the oscilloscope 4 may be, but is not limited to, a digital oscilloscope;

The output end of the multi-channel analyzer is also connected with a PC 5, and the PC 5 is used to calibrate and display the corresponding energy spectrum of the nuclear radiation ray according to the analysis result of the multi-channel analyzer.

The beneficial effect of the above technical solution is that the oscilloscope can accurately observe the shape and parameters of the signal output by the linear amplifier, so as to adjust the working parameters of the linear amplifier in real time. Using a PC can quickly and accurately calibrate the corresponding energy spectrum of the nuclear radiation ray according to the statistical results of the multi-channel analyzer, thereby improving the automation and intelligence of the nuclear radiation ray energy spectrum measurement.

Referring to FIG. 2 , it is a schematic diagram of the irradiation mode of infrared rays and rays in the infrared excitation type high-resolution cadmium zinc telluride nuclear radiation detection system provided by the present invention. It can be seen from FIG. 2 that the nuclear radiation rays such as X-rays and/or gamma rays emitted by the nuclear radiation emission source are irradiated to the detection surface in a direction perpendicular to the detection surface of the cadmium zinc telluride detector, which can ensure that the nuclear radiation The radiation beam can impinge on the detection surface without loss. The infrared light is irradiated on the four corner regions of the CdZnTe detector in an oblique manner. Since the electric field strength of the four corner regions of the CdZnTe detector is the weakest, the four corners are irradiated to the four corner regions. The carriers in the region are more easily captured, thereby maximizing the carrier transport efficiency of the CdZnTe detector, thereby improving the detection sensitivity and energy resolution of the CdZnTe detector.

It can be known from the content of the above embodiment that the infrared excitation type high-resolution cadmium zinc telluride nuclear radiation detection system includes an infrared excitation light source, a nuclear radiation emission source, a cadmium zinc telluride detector, a preamplifier and a spectrometer; the infrared excitation light source It is used to emit at least one beam of infrared light, and at least one beam of infrared light is irradiated on the detection surface of the cadmium zinc telluride detector at a corresponding inclination angle; the nuclear radiation emission source is used to emit nuclear radiation rays, and the nuclear radiation rays are irradiated vertically to the detection surface; the preamplifier is connected to the cadmium zinc telluride detector, which is used to convert the induced charge on the anode of the cadmium zinc telluride detector into an exponentially decaying voltage pulse signal; the spectrometer is connected to the preamplifier Amplifier connection, which is used for analyzing and processing the signal output by the preamplifier; it can be seen that the infrared excitation type high-resolution cadmium zinc telluride nuclear radiation detection system improves the loading of the cadmium zinc telluride crystal material through the external excitation mode of infrared irradiation. The carrier transmission efficiency, so that it is possible to irradiate tellurium with sub-gap infrared in a specific wavelength range without the need for crystal growth improvement, pulse signal correction processing and improvement of electrode structure design for the CdZnTe detector. The region with the weakest electric field in the ZnCd detector can excite the carriers in the ZnZnTe detector for efficient transport, thereby maximizing the detection sensitivity and energy resolution of the ZnZnTe detector, thereby reducing the ZnZnTe detector. Cost of cadmium detectors and improving detection reliability of cadmium zinc telluride detectors.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit and scope of the invention. Thus, provided that these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims (8)

1. The infrared excitation type high-resolution tellurium-zinc-cadmium nuclear radiation detection system is characterized by comprising an infrared excitation light source, a nuclear radiation emission source, a tellurium-zinc-cadmium detector, a preamplifier and a spectrometer; wherein,

the infrared excitation light source is used for emitting at least one beam of infrared light, and the at least one beam of infrared light irradiates the detection surface of the cadmium zinc telluride detector at a corresponding inclination angle;

the nuclear radiation emission source is used for emitting nuclear radiation rays which vertically irradiate the detection surface and are used for calibrating the energy spectrum of the cadmium zinc telluride detector;

the preamplifier is connected with the cadmium zinc telluride detector and is used for amplifying induced charges of the anode of the cadmium zinc telluride detector to obtain an exponential decay voltage pulse signal which is in direct proportion to ray energy;

the spectrometer is connected with the preamplifier and is used for analyzing and processing the signal output by the preamplifier;

the infrared excitation light source comprises an infrared LED, a light intensity adjuster, an infrared filter and an infrared light irradiation adjuster; wherein,

the light intensity adjuster is connected with the infrared LED and is used for adjusting the intensity of infrared light emitted by the infrared LED;

the infrared filter is arranged on a transmission path of infrared light emitted by the infrared LED and is used for filtering the infrared light so as to obtain the infrared light meeting a preset wavelength range;

the infrared light irradiation adjuster is used for converting infrared light meeting a preset wavelength range into at least one beam of infrared light and adjusting the inclination angle of the at least one beam of infrared light irradiating the detection surface;

wherein the infrared light irradiation adjuster includes an infrared beam splitter and an infrared beam diverter; wherein,

the infrared beam splitter is used for converging and/or splitting the infrared light output by the infrared filter so as to obtain at least one beam of infrared light;

the infrared light redirector is used for scanning and deflecting the at least one beam of infrared light so as to change the transmission direction of the at least one beam of infrared light, and therefore the at least one beam of infrared light irradiates the detection surface of the cadmium zinc telluride detector at a corresponding inclination angle.

2. The infrared-excited high-resolution cadmium zinc telluride nuclear radiation detection system as set forth in claim 1 wherein:

the light intensity adjuster comprises a slide resistor and a power supply;

the power supply is connected with the infrared LED through the sliding resistor;

the sliding resistor is used for changing the power supply current output by the power supply to the infrared LED, so that the intensity of infrared light emitted by the infrared LED is adjusted.

3. The infrared-excited high-resolution cadmium zinc telluride nuclear radiation detection system as set forth in claim 1 wherein:

the infrared filter is a narrow-band infrared filter plate;

the narrow-band infrared filter is used for filtering the infrared light, so that the infrared light with the wavelength range of 800-1200 nm and the bandwidth of 30-40 nm is obtained.

4. The infrared-excited high-resolution cadmium zinc telluride nuclear radiation detection system as set forth in claim 1 wherein:

the inclination angle is 30-75 degrees;

or,

the infrared excitation light source comprises an infrared light shielding box, and the infrared light shielding box is used for blocking infrared light from leaking to the external environment;

or,

the nuclear radiation emission source comprises a lead shielding box, and the lead shielding box is used for preventing nuclear radiation rays from leaking to the external environment;

or,

the cadmium zinc telluride detector and the preamplifier are jointly placed in a front-end shielding box;

or,

the tellurium-zinc-cadmium detector is a hemispherical tellurium-zinc-cadmium detector.

5. The infrared-excited high-resolution cadmium zinc telluride nuclear radiation detection system as set forth in claim 1 wherein:

the cathode of the cadmium zinc telluride detector is grounded;

the anode of the cadmium zinc telluride detector is connected with the input end of the preamplifier in an alternating current coupling mode;

and the anode of the cadmium zinc telluride detector is also connected with a power supply.

6. The infrared-excited high-resolution cadmium zinc telluride nuclear radiation detection system as set forth in claim 1 wherein:

the preamplifier is a charge sensitive preamplifier;

the charge sensitive preamplifier is used for amplifying the anode induced charge of the cadmium zinc telluride detector to obtain an exponential decay voltage pulse signal which is in direct proportion to ray energy.

7. The infrared-excited high-resolution cadmium zinc telluride nuclear radiation detection system as set forth in claim 6 wherein:

the spectrometer comprises a linear amplifier and a multi-channel analyzer;

the input end of the linear amplifier is connected with the charge sensitive preamplifier and is used for shaping the exponential decay voltage pulse signal into a Gaussian pulse signal and linearly amplifying the Gaussian pulse signal;

and the input end of the multichannel analyzer is connected with the output end of the linear amplifier and is used for analyzing the linearly amplified Gaussian pulse signal.

8. The infrared-excited high-resolution cadmium zinc telluride nuclear radiation detection system as set forth in claim 7 wherein:

the output end of the linear amplifier is also connected with an oscilloscope;

the output end of the multichannel analyzer is further connected with a PC (personal computer), and the PC is used for calibrating the energy spectrum corresponding to the nuclear radiation rays according to the analysis result of the multichannel analyzer.

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