A device for generating gamma pulse radiation based on free fall

Abstract

The present invention relates to a device for generating gamma pulse radiation based on free fall, belonging to the field of ionizing radiation measurement technology. The device comprises a source container with a shutter and a lead shield. The source container can generate a radiation beam through a radiation outlet of the source container. The lead shield is close to the shutter and has a steel cladding on its outer layer. A circular lead shield radiation outlet is opened on the central axis of the upper position of the lead shield and penetrates the lead shield and the steel cladding. The device also includes a main bracket, which is provided with a guide rail, a slider is installed on the guide rail, and the lead shield is fixed to the slider. The upper end of the main bracket is provided with a top bracket, which is provided with a motor. The output shaft end of the motor is connected to an electromagnet via a nylon rope. The electromagnet is connected to the upper end surface of the lead shield by magnetic force. The device provided by the present invention can generate pulsed gamma radiation of different pulse widths, providing a reliable pulse radiation field for the research and development, calibration and verification of critical safety alarms and other related instruments.

Description

Technical Field

[0001] The present invention belongs to the technical field of ionizing radiation measurement, and in particular relates to a device for generating gamma pulse radiation based on free fall. Background Art

[0002] Pulsed gamma radiation is a unique type of nuclear radiation that is difficult to measure. In criticality safety accidents, it is necessary to detect and generate an alarm to alert personnel to evacuate safely. However, due to the current lack of devices capable of generating pulsed gamma radiation with pulse widths on the order of milliseconds, the reliability of criticality safety alarms and other related instruments has not been fully verified. Summary of the Invention

[0003] In order to address the defects of the existing technology, the purpose of the present invention is to provide a device for generating gamma pulse radiation based on free fall. The device can generate pulsed gamma radiation with different pulse widths, providing a reliable pulse radiation field for the research and development, calibration and verification of critical safety alarms and other related instruments.

[0004] In order to achieve the above purpose, a technical solution adopted by the present invention is:

[0005] A device for generating gamma pulse radiation based on free fall, comprising: a source container and a lead shield; a circular source container radiation outlet is provided on a side wall of the source container; a shutter is provided outside the source container radiation outlet; the source container can generate a radiation beam through the source container radiation outlet;

[0006] The lead shield is close to the shutter, and the outer layer of the lead shield is provided with a steel cladding. A circular lead shield radiation outlet is provided on the central axis of the upper portion of the lead shield, and the lead shield radiation outlet passes through the lead shield and the steel cladding.

[0007] The device also includes a main support, the main support is provided with a guide rail, the guide rail is installed with a slider, the lead shield is fixed to the slider and can move up and down along the guide rail, so that the central axis of the radiation outlet of the lead shield can coincide with the central axis of the radiation outlet of the source container at a set time;

[0008] A top bracket is provided at the upper end of the main bracket, and a motor is fixedly provided on the top bracket. The output shaft end of the motor is connected to an electromagnet through a nylon rope. The electromagnet is connected to the upper end surface of the lead shielding body through magnetic force, and the lead shielding body is lifted by the rotation of the motor.

[0009] Furthermore, in the above-mentioned device for generating gamma pulse radiation based on free fall, the diameters of the radiation exit port of the lead shield and the radiation exit port of the source container are equal.

[0010] Furthermore, for the device for generating gamma pulse radiation based on free fall as described above, the pulse width of the required gamma pulse is calculated by the following formula:

[0011]

[0012] Wherein, T is the pulse width of the required γ pulse, d is the diameter of the ray exit port of the lead shield and the ray exit port of the source container, and v is the movement speed of the lead shield at the moment before the pulse is generated.

[0013] Furthermore, the device for generating gamma pulse radiation based on free fall as described above determines the required pulse width of the gamma pulse based on the pulse width of the gamma pulse generated by a simulated nuclear criticality accident, determines the movement speed of the lead shield based on the required pulse width of the gamma pulse, and then determines the height to which the lead shield needs to be lifted.

[0014] Furthermore, for the device for generating gamma pulse radiation based on free fall as described above, the required pulse width of the gamma pulse is in the range of 60ms to 140ms, and the movement speed of the lead shield is ≥3.1m / s.

[0015] Furthermore, in the above-mentioned apparatus for generating gamma pulse radiation based on free fall, the source container is arranged on a source container holder.

[0016] Furthermore, in the apparatus for generating gamma pulse radiation based on free fall as described above, the main support and the source container support are arranged on a supporting platform, and the supporting platform is arranged on a supporting platform support.

[0017] Furthermore, in the above-mentioned device for generating gamma pulse radiation based on free fall, a buffer pad is provided on the support platform at a position corresponding to the bottom end of the lead shield, for providing buffering for the free fall motion of the lead shield.

[0018] Furthermore, in the device for generating gamma pulse radiation based on free fall as described above, there are two guide rails, which are parallel to each other and symmetrically arranged; there are four sliders, which are symmetrically installed at both ends of the lead shield.

[0019] Furthermore, when the device for generating gamma pulse radiation based on free fall as described above is used for calibration and performance testing of a nuclear criticality accident gamma radiation alarm, the distance between the detection unit of the nuclear criticality accident gamma radiation alarm and the radiation source is determined based on the required gamma pulse dose rate; based on the size of the detection unit and the distance from the detection unit to the radiation source, and on the premise of ensuring that the quality of the radiation field meets the requirements, the diameter of the ray exit port of the lead shield is determined to ensure that the effective area of the radiation field can completely cover the detection unit.

[0020] The device for generating gamma pulse radiation based on free fall described in the present invention applies free fall motion characteristics to a lead shielding body, causing the lead shielding body to move relative to a ray exit port, thereby constructing a single pulse gamma ray capable of generating pulse width and dose characteristics that meet requirements, forming a single pulse gamma ray radiation field, thereby calibrating measuring instruments for measuring single pulse gamma rays. The device can be used for calibration and performance testing of nuclear criticality accident gamma radiation alarms, and can also be applied to performance evaluation of other instruments and equipment used for single pulse X and gamma radiation measurement. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 1 is a schematic structural diagram of a device for generating gamma pulse radiation based on free fall provided in an embodiment of the present invention;

[0022] In the figure: 1-motor; 2-top bracket; 3-nylon rope; 4-electromagnet; 5-main bracket; 6-slider; 7-ray exit port of lead shield; 8-lead shield; 9-shutter; 10-ray exit port of source container; 11-source container; 12-guide rail; 13-source container bracket; 14-support platform; 15-buffer pad; 16-support platform bracket. DETAILED DESCRIPTION

[0023] The present invention will be further described below in conjunction with specific embodiments and the accompanying drawings.

[0024] Figure 1 A schematic diagram of the structure of a device for generating gamma pulse radiation based on free fall, provided by an embodiment of the present invention, is shown. The device includes: a rectangular lead shield 8 and a source container 11. A circular source container radiation outlet 10 is provided on a side wall of the source container 11. A shutter 9 is provided outside the source container radiation outlet 10. When the shutter 9 is opened, the source container 11 generates a radiation beam through the source container radiation outlet 10. A side wall of the lead shield 8 is close to the shutter 9 of the source container 11. The outer layer of the lead shield 8 is provided with a steel cladding. A circular lead shield radiation outlet 7 is provided on the central axis of the upper portion of the lead shield 8. The lead shield radiation outlet 7 passes through the lead shield 8 and the steel cladding.

[0025] The device also includes a main bracket 5, which is provided with a guide rail 12, and a slider 6 is installed on the guide rail 12. The lead shield 8 is fixed on the slider 6 and can move up and down along the guide rail 12, so that the central axis of the lead shield's radiation outlet 7 can coincide with the central axis of the source container's radiation outlet 10 at a certain moment; a top bracket 2 is provided at the upper end of the main bracket 5, and a motor 1 is fixedly provided on the top bracket 2. The output shaft end of the motor 1 is connected to the electromagnet 4 through a nylon rope 3, and the electromagnet 4 is connected to the upper end surface of the lead shield 8 through magnetic force. The lead shield 8 can be lifted by rotating the motor 1.

[0026] In the embodiment of the present invention, the diameters of the ray exit opening 7 of the lead shield and the ray exit opening 10 of the source container are equal, and the size of the ray exit opening 7 of the lead shield will not change once it is set.

[0027] In the embodiment of the present invention, the pulse width of the required γ pulse can be calculated by the following formula:

[0028]

[0029] Wherein, T is the pulse width of the required γ pulse, d is the diameter of the ray exit port 7 of the lead shield and the ray exit port 10 of the source container, and v is the moving speed of the lead shield 8 at the moment before the pulse is generated.

[0030] The required gamma pulse width is determined by the pulse width of the gamma pulse generated by the simulated nuclear criticality accident and ranges from 60 ms to 140 ms. The movement speed of the lead shield 8 depends on the required gamma pulse width and is used to determine the height to which the lead shield 8 is lifted. The movement speed v of the lead shield 8 is at least 3.1 m / s.

[0031] In the embodiment of the present invention, the source container 11 is disposed on a source container support 13 .

[0032] In the embodiment of the present invention, the main support 5 and the source container support 13 are arranged on a support platform 14 , and the support platform 14 is arranged on a support platform support 16 .

[0033] In this embodiment of the present invention, a cushion pad 15 is provided on the support platform 14 at a position corresponding to the bottom end of the lead shield 8 to cushion the free fall of the lead shield 8. The thickness of the cushion pad 15 is determined by the total weight of the lead shield 8 and the slider, thereby providing a better deceleration and cushioning effect.

[0034] In the embodiment of the present invention, there are two guide rails 12 , which are parallel to each other and symmetrically arranged; there are four sliders 6 , which are symmetrically installed at both ends of the lead shield 8 .

[0035] When using the above device, electromagnet 4 is first energized, and then lead shield 8 is raised to the desired height via motor 1. Shutter 9 is then opened, de-energizing electromagnet 4, causing slider 6 and lead shield 8 to freely fall, resulting in the generated gamma pulse being emitted from lead shield radiation outlet 7. Specifically, the required movement speed of lead shield 8 can be determined based on the desired pulse width of the gamma pulse, and the required movement speed can be achieved by adjusting the drop height of lead shield 8.

[0036] When the above-mentioned radiation device is used for calibration and performance testing of nuclear criticality accident gamma radiation alarms:

[0037] Based on the required gamma pulse dose rate, the distance between the detection unit of the nuclear criticality accident gamma radiation alarm and the radiation source is calculated; based on the size of the detection unit of the nuclear criticality accident gamma radiation alarm and the distance between the detection unit and the radiation source, and on the premise that the radiation field quality meets the requirements, the diameter of the radiation exit port is determined so that the effective area of the radiation field can completely cover the detection unit.

[0038] The device for generating gamma pulse radiation based on free fall provided by the present invention applies free fall motion characteristics to a lead shielding body, causing the lead shielding body to move relative to a ray exit port, thereby constructing a single pulse gamma ray capable of generating pulse width and dose characteristics that meet requirements, forming a single pulse gamma ray radiation field, and thereby calibrating measuring instruments for measuring single pulse gamma rays. The device can be used for calibration and performance testing of nuclear criticality accident gamma radiation alarms, and can also be applied to performance evaluation of other instruments and equipment used for single pulse X and gamma radiation measurement.

[0039] The above embodiments are merely illustrative of the present invention, and the present invention may also be implemented in other specific ways or in other specific forms without departing from the gist or essential characteristics of the present invention. Therefore, the described embodiments are to be considered in all respects as illustrative and not restrictive. The scope of the present invention is to be determined by the appended claims, and any variations equivalent to the intent and scope of the claims are intended to be within the scope of the present invention.

Claims

1. A device for generating gamma pulse radiation based on free fall, characterized in that: The device comprises: a source container (11) and a lead shield (8); a circular source container radiation outlet (10) is provided on a side wall of the source container (11); a shutter (9) is provided outside the source container radiation outlet (10); and the source container (11) can generate a radiation beam through the source container radiation outlet (10); The lead shield (8) is close to the shutter (9), the outer layer of the lead shield (8) is provided with a steel shell, a circular lead shield ray exit port (7) is provided on the central axis of the upper position of the lead shield (8), and the lead shield ray exit port (7) passes through the lead shield (8) and the steel shell; The device further comprises a main support (5), a guide rail (12) is provided on the main support (5), a slider (6) is mounted on the guide rail (12), the lead shield (8) is fixed on the slider (6), and can move up and down along the guide rail (12), so that the central axis of the radiation outlet (7) of the lead shield can coincide with the central axis of the radiation outlet (10) of the source container at a set time; A top bracket (2) is provided at the upper end of the main bracket (5), a motor (1) is fixedly provided on the top bracket (2), an output shaft end of the motor (1) is connected to an electromagnet (4) via a nylon rope (3), the electromagnet (4) is connected to the upper end surface of the lead shielding body (8) via magnetic force, and the lead shielding body (8) is lifted by the rotation of the motor (1).

2. The device for generating gamma pulse radiation based on free fall according to claim 1, characterized in that: The diameters of the lead shielding body radiation outlet (7) and the source container radiation outlet (10) are equal.

3. The device for generating gamma pulse radiation based on free fall according to claim 2, characterized in that: The required pulse width of the γ pulse is calculated by the following formula: Wherein, T is the pulse width of the required gamma pulse, d is the diameter of the ray exit port (7) of the lead shield and the ray exit port (10) of the source container, and v is the movement speed of the lead shield (8) at the moment before the pulse is generated.

4. The device for generating gamma pulse radiation based on free fall according to claim 3, characterized in that: The pulse width of the required gamma pulse is determined according to the pulse width of the gamma pulse generated by the simulated nuclear criticality accident, the movement speed of the lead shield (8) is determined according to the pulse width of the required gamma pulse, and then the height to which the lead shield (8) needs to be lifted is determined.

5. The device for generating gamma pulse radiation based on free fall according to any one of claims 1 to 4, characterized in that: The required pulse width of the gamma pulse is in the range of 60ms to 140ms, and the moving speed of the lead shield (8) is ≥3.1m / s.

6. The device for generating gamma pulse radiation based on free fall according to claim 1, characterized in that: The source container (11) is arranged on a source container support (13).

7. The device for generating gamma pulse radiation based on free fall according to claim 6, characterized in that: The main support (5) and the source container support (13) are arranged on a support platform (14), and the support platform (14) is arranged on a support platform support (16).

8. The device for generating gamma pulse radiation based on free fall according to claim 7, characterized in that: A buffer pad (15) is provided on the support platform (14) at a position corresponding to the bottom end of the lead shield (8), for providing buffering for the free-fall motion of the lead shield (8).

9. The device for generating gamma pulse radiation based on free fall according to any one of claims 6 to 8, characterized in that: There are two guide rails (12), which are parallel to each other and symmetrically arranged; there are four sliders (6), which are symmetrically installed at both ends of the lead shielding body (8).

10. The device for generating gamma pulse radiation based on free fall according to claim 1, characterized in that: When the device is used for calibration and performance testing of a nuclear criticality accident gamma radiation alarm, the distance between the detection unit of the nuclear criticality accident gamma radiation alarm and the radiation source is determined based on the required gamma pulse dose rate; based on the size of the detection unit and the distance between the detection unit and the radiation source, and on the premise that the radiation field quality meets the requirements, the diameter of the ray exit port (7) of the lead shield is determined so that the effective area of the radiation field can completely cover the detection unit.

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