CN111239579A - X-ray detector electrical parameter testing system and testing method thereof - Google Patents

Abstract

The invention discloses an X-ray detector electrical parameter testing system, comprising: a shielding box for placing an X-ray light source, a lifting frame, a support arm and a sample box; and an instrument cabinet for installation X-ray tube power supply, X-ray tube controller, semiconductor parameter analyzer, electrometer and control computer; a vacuum unit, the vacuum unit is connected with a valve through a gas pipe to evacuate the sample box; the present invention also proposes an X-ray detector A method for testing electrical parameters, comprising the following steps: placing and fixing an X-ray detector on the bottom of a sample box, welding two electrode leads to the core posts of two coaxial electrical connectors, covering and fixing the sample box with screws Seal the cap and conduct electrical parameter testing. This system has the advantages of multi-function and multi-parameter testing, and can perform a relatively complete test and evaluation of the electrical parameters of the X-ray detector. It is an important tool for developing new or high-performance detectors.

Description

X-ray detector electrical parameter testing system and testing method thereof

technical field

The invention relates to the technical field of electrical parameter testing of optoelectronic semiconductors and photoelectric detectors, in particular to an X-ray detector electrical parameter testing system and a testing method thereof.

Background technique

X-ray detectors are an important class of sensors that can be used in many fields such as environmental radiation monitoring, medical X-ray therapy dose monitoring, and X-ray communication. X-ray detectors based on semiconductor materials have the characteristics of small size, easy integration and excellent detection performance, such as silicon photodiodes (Si-PIN), silicon photomultipliers (SiPM), cadmium telluride (CdTe), cadmium zinc telluride ( CdZnTe) and other more mature solid-state X-ray detectors. In recent years, new materials suitable for the development of X-ray detectors have also been developed, such as compound semiconductors such as BiI ₃ , PbI ₂ , CsPbBr ₃ , CsPbI ₃ , CH ₃ NH ₃ PbI ₃ , Cs ₂ BiAgBr ₆ and diamond.

The electrical parameters of X-ray detectors based on the above-mentioned novel compound semiconductors are an important basis for evaluating the device performance. The electrical parameters include the current value and resistance value of the detector when there is no light at room temperature, which are called dark current and dark resistance; the current value and resistance value of the detector when X-ray is irradiated, which are called photoresistance and photocurrent; The current value under the set voltage is called the current-voltage curve; and the response current curve of the device when it is repeatedly turned on or irradiated by tube X-rays. Since air also interacts with X-ray ionization, ionization currents can be observed in high-sensitivity meters, which will affect the electrical parameter testing of the detectors studied. Therefore, in order to reduce the impact of air ionization on the test, the detector can be placed in the evacuated sample box, and a mechanical pump can be selected to pump to a low vacuum, or a mechanical pump plus a molecular pump can be used to pump to a high vacuum according to the measurement needs.

The metal shielding box with the lead plate core can not only prevent the X-ray overflow from causing harm to the human body, but also avoid light, shield electromagnetic interference, and improve the measurement accuracy.

At present, there is no mature and systematic X-ray detector electrical parameter testing system and its testing method for evaluating the electrical performance of X-ray detectors.

SUMMARY OF THE INVENTION

The purpose of the present invention is to solve the shortcomings existing in the prior art, and the proposed X-ray detector electrical parameter testing system and its testing method have the advantages of multi-function and multi-parameter testing, and can test the electrical parameters of the X-ray detector. It is an important tool to develop new or high-performance detectors for more complete testing and evaluation of parameters.

In order to achieve the above object, the present invention adopts the following technical solutions:

X-ray detector electrical parameter test system, including:

a shielding box for placing the X-ray light source, the lifting frame, the support arm and the sample box;

an instrument cabinet for installing an X-ray tube power supply, an X-ray tube controller, a semiconductor parameter analyzer, an electrometer, a source measurement unit, and a control computer;

a vacuum unit, the vacuum unit is connected with the valve through the gas pipe, and the sample box is evacuated;

It also includes a number of cables and a number of electrical connectors to connect the X-ray light source and sample in the shielded box to the X-ray tube power supply, X-ray tube controller, semiconductor parameter analyzer, electrometer, source measure unit and on the instrument cabinet. The control computer is electrically connected.

Preferably, the shielding box is made of a lead plate with a metal encapsulation layer.

Preferably, the X-ray light source is mounted on a support arm.

Preferably, the sample cartridge is made of cylindrical metal, containing a valve, a plurality of electrical connections and a sealing lid with a window.

Preferably, the sample box is installed just below the exit window of the X-ray light source.

Preferably, the vacuum unit adopts a mechanical pump or a combination of a mechanical pump and a molecular pump.

Preferably, the electrical connector adopts a low-noise coaxial connector, and the cable adopts a low-noise coaxial cable.

The present invention also proposes a method for testing the electrical parameters of the X-ray detector, comprising the following steps:

S1. Place and fix the X-ray detector on the bottom of the sample box, weld the electrode leads to the core column of the coaxial electrical connector respectively, cover and fix the sealing cover of the sample box with screws;

S2. Place the sample box directly under the exit window of the X-ray light source, and make the window of the sample box face the exit window of the X-ray light source, connect the trachea to the valve of the sample box, and connect the electrical signal cable to the coaxial connector of the sample box. connect;

S3. Turn on the vacuum unit to evacuate the sample box, manually rotate the lifting frame runner to adjust the distance between the sample box window and the exit window of the X-ray light source, and close the front door of the shielding box;

S4. Turn on the semiconductor analyzer and set the curve to be measured, such as the dark current-time curve under a fixed bias voltage, and obtain the curve through testing;

S5. Turn on the power of the X-ray light source, the software on the controller and the control computer, set the required tube voltage and tube current, and the irradiation duration, turn on the light source to illuminate the detector, and trigger the semiconductor analyzer to perform X-ray irradiation. Current-time curve test;

S6. After a series of tests are completed, turn off the X-ray light source, semiconductor parameter analyzer, and vacuum unit.

The present invention has the following beneficial effects:

1. The X-ray detector electrical parameter testing system and its testing method of the present invention can realize the resistance value and current value of the X-ray detector without light, the resistance value and current value of X-ray irradiation, and the current without light and X-ray irradiation. - Voltage curve, current-time curve without light and X-ray irradiation, response current curve of repeatedly turning on or off X-ray irradiation, and testing of multiple electrical parameters such as the amount of charge under X-ray irradiation.

2. Semiconductor parameter analyzer or electrometer or source measurement unit can be selected as required to meet the requirements of test accuracy, speed and function. According to the needs, a mechanical pump or a combination of a mechanical pump and a molecular pump can be used to draw a low or high vacuum on the sample box to reduce the influence of air on the test results; even, in the simplest test, no vacuum is required.

3. Both the X-ray and the detector are placed in a metal box shielded by radiation, electromagnetic and light, which fully guarantees the safety of the test and the reliability of the test results.

4. The electrical signal paths are connected by low-noise coaxial connectors and coaxial cables, which ensures the effective transmission of weak signals, helps to observe and analyze the sensitive signals of the detector, and improves the extraction range, precision and accuracy of electrical parameters. Spend.

5. This system has the advantages of multi-function and multi-parameter testing, which can conduct a relatively complete test and evaluation of the electrical parameters of X-ray detection, and is an important tool for developing new or high-performance detectors.

Description of drawings

Fig. 1 is the overall structure composition schematic diagram of the present invention;

FIG. 2 is a schematic structural diagram of the sample box of the present invention.

In the picture: 1 shielding box, 101 X-ray light source, 102 sample box, 103 X-ray light source exit window, 104 lift frame, 105 lift frame manual runner, 106 support arm, 107 sample box window, 108, 109 electrical connector, 110 cable , 111, 112 valves, 113 trachea, 114 fixing screws, 115 X-ray detectors;

2 Instrument cabinet, 201, 202 cables, 203 X-ray tube power supply, 204 X-ray tube controller, 205 Semiconductor parameter analyzer, 206, 208 cables, 207 Electrometer, 209 Source measurement unit, 210 Control computer;

3 vacuum units.

Detailed ways

In order to make the above objects, features and advantages of the present invention more clearly understood, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific implementation disclosed below.

It should be noted that when an element is referred to as being "fixed to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for the purpose of illustration only and do not represent the only embodiment.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terms used herein in the description of the present invention are for the purpose of describing specific embodiments only, and are not intended to limit the present invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

1-2, the overall structure of the X-ray detector electrical parameter testing system is shown in FIG. 1, including: a shielding box 1 for placing an X-ray light source 101, a lifting frame 104, a support arm 106 and a sample box 102;

The instrument cabinet 2 is used to install the X-ray tube power supply 203, the X-ray tube controller 204, the semiconductor parameter analyzer 205, the electrometer 207, the source measurement unit 209 and the control computer 210;

The vacuum unit 3 is connected to the valve 111 through the air pipe 113, and the sample box 102 is evacuated;

A plurality of cables 110, 201, 202, 206, 208 and a plurality of electrical connectors 108, 109 connect the X-ray light source 101 and the sample and 102 in the shielding box 1 to the X-ray tube power supply 203 on the instrument cabinet 2, X-ray The tube controller 204 , the semiconductor parameter analyzer 205 , the electrometer 207 , the source measurement unit 209 , and the control computer 210 are electrically connected.

The shielding box 1 is made of a lead plate with a metal encapsulation layer, and has triple functions of blocking X-rays, avoiding light, and shielding external electromagnetic interference;

The X-ray light source 101 is installed on the support arm 106, and the distance from the sample box 102 is adjusted by rotating the manual wheel 105 of the lifting frame 104 at the same time; the sample box 102 is made of cylindrical metal, and contains a valve 111, a plurality of electrical Joint 108 and sealing cover with window 107;

The sample box 102 is installed directly below the exit window 103 of the X-ray light source 101. During the test, the sample box window 107 and the exit window 103 are kept vertically opposite to the center; the electrical connectors 108 and 109 are low-noise coaxial connectors. 202, 206, 208 use low-noise coaxial cables;

According to actual needs, the semiconductor parameter analyzer 205, electrometer 207 or source measurement unit 209 can be selected; according to actual needs, the vacuum unit 3 can be selected from a mechanical pump or a combination of a mechanical pump and a molecular pump.

The system can test the resistance value and current value of the detector sample 115 without light, the resistance value and current value of X-ray irradiation, the current-voltage curve without light and with X-ray irradiation, and the current-voltage curve without light and with X-ray irradiation. Time curve, response current curve of repeatedly turning on or off X-ray irradiation, charge amount under X-ray irradiation.

As an example, the shielding box is made of stainless steel encased lead sheets.

As an example, the X-ray light source adopts a highly integrated product or device to meet the requirement of miniaturization.

As an example, the lift frame uses a manual screw slide module.

As an example, the electrical connectors on the sample box can be arranged into 3 pairs of 6 low-noise triaxial connectors according to actual needs.

As an example, the window on the sealed lid of the sample box uses a pure graphite plate that absorbs less X-rays.

As an example, the test instrument selects a semiconductor parameter analyzer.

As an example, the vacuum unit uses a mechanical pump to pump low vacuum.

As an example, the electrical signal paths are all connected using low-noise triax cables.

As an example, a semiconductor parameter analyzer can be used to measure the current value of the detector sample without light, the current value of X-ray irradiation, the current-voltage curve without light and with X-ray irradiation, and the current-time curve without light and with X-ray irradiation , the response current curve of repeatedly turning on or off X-ray irradiation.

The present invention also proposes a method for testing the electrical parameters of the X-ray detector, comprising the following steps:

S1, place and fix the X-ray detector on the bottom of the sample box 102, solder the two electrode leads to the core posts of the two coaxial electrical connectors, cover and fix the sealing cover of the sample box 102 with screws;

S2, place the sample box 102 directly below the X-ray light source exit window 103, and make the sample box window 107 and the X-ray light source exit window 103 directly opposite, connect the air tube 113 to the sample box valve, and connect the electrical signal cable 110 to the The sample box is connected with the coaxial connector;

S3, turn on the vacuum unit 3 to evacuate the sample box 102, manually rotate the lifting frame runner 105 to adjust the distance between the sample box window 107 and the X-ray light source exit window 103, and close the front door of the shielding box;

S4. Turn on the semiconductor analyzer and set the curve to be measured, such as the dark current-time curve under a fixed bias voltage, and obtain the curve through testing;

S5. Turn on the power supply 203 of the X-ray light source, the software on the controller and the control computer 210, set the required tube voltage and tube current, and the irradiation duration, turn on the light source to irradiate the detector, and trigger the semiconductor analyzer to perform X-ray irradiation at the same time The current-time curve test under the

S6. After a series of tests are completed, turn off the X-ray light source, semiconductor parameter analyzer, and vacuum unit.

It should be noted that, according to the structure and configuration of a specific X-ray detector, the number of electrode leads is uncertain. Therefore, the number of electrical connectors on the sample box, the number of electrical connectors on the shielding box, and the number of cables can be expanded according to the situation, but this does not involve changes in the basic structure, and is within the protection scope of the present invention.

In addition, according to the actual situation such as cost, function, accuracy and other requirements, the system may not contain a vacuum unit, or the test instrument only uses one of semiconductor parameter analysis, electrometer, and source measurement unit, but this does not involve the change of the basic structure , also within the protection scope of the present invention.

The above description is only a preferred embodiment of the present invention, but the protection scope of the present invention is not limited to this. The equivalent replacement or change of the inventive concept thereof shall be included within the protection scope of the present invention.

Claims (9)

1. An X-ray detector electrical parameter testing system, comprising:

   a shielding box (1), wherein the shielding box (1) is used for placing an X-ray light source (101), a lifting frame (104), a supporting arm (106) and a sample box (102);

   an instrument cabinet (2), the instrument cabinet (2) is used for installing an X-ray tube power supply (203), an X-ray tube controller (204), a semiconductor parameter analyzer (205), an electrometer (207), a source measuring unit (209) and a control computer (210);

   the vacuum unit (3) is connected with the valve (111) through an air pipe (113) and is used for vacuumizing the sample box (102);

   the X-ray tube shielding box further comprises a plurality of cables (110, 201, 202, 206, 208) and a plurality of electric connectors (108, 109), wherein the X-ray light source (101) and the samples (115) and (102) in the shielding box (1) are electrically connected with an X-ray tube power supply (203), an X-ray tube controller (204), a semiconductor parameter analyzer (205), an electrometer (207), a source measuring unit (209) and a control computer (210) on the instrument cabinet (2).
2. 2. The system for testing electrical parameters of an X-ray detector according to claim 1, characterized in that the shielding box (1) is made of a lead plate with a metal envelope.
3. 3. The X-ray detector electrical parameter testing system of claim 1, characterized in that the X-ray light source (101) is mounted on a support arm (106).
4. 4. The X-ray detector electrical parameter testing system of claim 1, characterized in that the sample cartridge (102) is made of cylindrical metal, comprising a valve (111), a plurality of electrical connectors (108) and a sealing lid with a window sheet (107).
5. 5. The X-ray detector electrical parameter testing system of claim 1, characterized in that the sample cartridge (102) is mounted directly below an exit window (103) of an X-ray light source (101).
6. 6. The X-ray detector electrical parameter testing system according to claim 1, characterized in that the vacuum unit (3) employs a mechanical pump or a combination of a mechanical pump and a molecular pump.
7. 7. The X-ray detector electrical parameter testing system of claim 1, characterized in that the electrical connectors (108, 109) are low noise coaxial connectors and the cables (110, 201, 202, 206, 208) are low noise coaxial cables.
8. 8. The X-ray detector electrical parameter testing system of claim 1, wherein: the system can be used for testing the electrical parameters of a detector sample (115), such as a non-irradiation resistance value, a current value, an X-ray irradiation resistance value, a current-voltage curve without irradiation of light and X-ray, a current-time curve without irradiation of light and X-ray, a response current curve with repeated on-off of X-ray irradiation, the charge quantity under the irradiation of X-ray, and the like.
9. The method for testing the electrical parameters of the X-ray detector is characterized by comprising the following steps:

   s1, placing and fixing the X-ray detector at the bottom of the sample box (102), welding electrode leads to core wire columns of coaxial electric connectors respectively, covering and fixing a sealing cover of the sample box (102) by using screws;

   s2, placing the sample box (102) right below the X-ray light source exit window (103), enabling the sample box window (107) to be opposite to the X-ray light source exit window (103), connecting the air pipe (113) with the sample box valve, and connecting the electric signal cable (110) with the sample box coaxial connector;

   s3, opening a vacuum unit (3) to vacuumize a sample box (102), manually rotating a lifting frame rotating wheel (105) to adjust the distance between a sample box window (107) and an X-ray light source exit window (103), and closing the front door of a shielding box;

   s4, opening the semiconductor analyzer and setting a curve to be measured, such as a dark current-time curve under a fixed bias, and obtaining the curve through testing;

   s5, turning on a power supply (203) of the X-ray light source, a controller and software on a control computer (210), setting required tube voltage and tube current and irradiation duration, turning on the light source to irradiate the detector, and simultaneously triggering the semiconductor analyzer to perform current-time curve test under X-ray irradiation;

   and S6, after a series of tests are finished, closing the X-ray light source, the semiconductor parameter analyzer and the vacuum unit.

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