阅读说明：本技术 采用CMOS图像传感器测量Rn-222的装置及方法 (Device and method for measuring Rn-222 by adopting CMOS image sensor ) 是由 谭延亮 林芬 王璐薇 谢若梅 范钟凯 胡滔 莫贻香 刘帅彬 袁帅 袁红志 于 2021-07-27 设计创作，主要内容包括：采用CMOS图像传感器测量Rn-222的装置及方法,装置包括测量腔、CMOS图像传感器、计算机、高压触头、高压模块、氡室、第一电磁阀、第二电磁阀及气泵。测量腔下部的筒壁上设有第一气管阀门及第二气管阀门,CMOS图像传感器安装在测量腔的端盖上,CMOS图像传感器通过USB线与计算机连接,高压触头通过导线与高压模块连接,第一气管阀门与第一电磁阀连接,第一电磁阀的另一端与氡室连接,第二气管阀门与第二电磁阀连接,第二电磁阀的另一端与气泵连接,气泵的另一端与氡室连接。测量时,利用CMOS图像传感器通过测量β射线和γ射线的数量来得到Rn-222的浓度。本发明的装置成本低,利用CMOS图像传感器通过测量β射线和γ射线的数量来得到Rn-222的浓度,测量灵敏度高。(The device comprises a measuring cavity, the CMOS image sensor, a computer, a high-voltage contact, a high-voltage module, a radon chamber, a first electromagnetic valve, a second electromagnetic valve and an air pump. The cylinder wall of the lower portion of the measuring cavity is provided with a first air pipe valve and a second air pipe valve, the CMOS image sensor is installed on an end cover of the measuring cavity and connected with a computer through a USB wire, the high-voltage contact is connected with the high-voltage module through a wire, the first air pipe valve is connected with the first electromagnetic valve, the other end of the first electromagnetic valve is connected with the radon chamber, the second air pipe valve is connected with the second electromagnetic valve, the other end of the second electromagnetic valve is connected with the air pump, and the other end of the air pump is connected with the radon chamber. During measurement, the concentration of Rn-222 is obtained by measuring the quantity of beta rays and gamma rays by using a CMOS image sensor. The device has low cost, obtains the Rn-222 concentration by measuring the quantity of beta rays and gamma rays by utilizing the CMOS image sensor, and has high measurement sensitivity.)

1. Adopt CMOS image sensor to measure Rn-222's device, characterized by: the radon measuring device comprises a measuring cavity, a CMOS image sensor, a computer, a high-voltage contact, a high-voltage module, a radon chamber, a first electromagnetic valve, a second electromagnetic valve and an air pump;

the cylinder wall at the lower part of the measuring cavity is provided with a first air pipe valve and a second air pipe valve, a CMOS image sensor is arranged on an end cover of the measuring cavity and is connected with a computer through a USB wire and used for observing experimental phenomena and processing data, a high-voltage contact is arranged on the cylinder wall at the upper part of the measuring cavity and is connected with a high-voltage module through a wire, the first air pipe valve is connected with a first electromagnetic valve through a pipeline, the other end of the first electromagnetic valve is connected with a radon chamber through a pipeline, the second air pipe valve is connected with a second electromagnetic valve through a pipeline, the other end of the second electromagnetic valve is connected with an air pump through a pipeline, and the other end of the air pump is connected with the radon chamber through a pipeline;

the inner wall of the measuring cavity is made of conductive metal, the high-voltage module generates high voltage on the inner wall of the measuring cavity through the high-voltage contact, metal wiring is contained in the CMOS image sensor, low voltage is generated during working, and the high voltage on the inner wall of the measuring cavity and the low voltage of the CMOS image sensor form an electrostatic field.

2. The method for measuring Rn-222 using the apparatus for measuring Rn-222 using a CMOS image sensor as claimed in claim 1, wherein:

when measurement is started, the first air pipe valve and the second air pipe valve are opened, Rn-222 is pumped from the radon chamber through the air pump, enters the measurement cavity through the second electromagnetic valve, and is sent back to the radon chamber through the first electromagnetic valve by the first air pipe valve to form a closed loop;

during the decay process of Rn-222, Pb-214, Bi-214 and Po-214 can generate beta rays and gamma rays, the beta rays and the gamma rays interact with the CMOS image sensor, electric charges generated by ionization can be collected by pixels on the CMOS image sensor and form pixel clusters, and under the condition that the decay process reaches the balance, the total count of the pixel clusters is proportional to the concentration of the Rn-222;

because the high-voltage module generates high voltage electricity on the inner wall of the measuring cavity through the high-voltage contact and forms an electrostatic field with the low voltage of the CMOS image sensor, radon daughter generated by the decay of Rn-222 in the measuring cavity is collected on the surface of the CMOS image sensor under the action of the electrostatic field, after a period of time, when the decay in the measuring cavity reaches balance, video shooting is completed by the CMOS image sensor within the measuring time, then the video is split into a frame image, the number of pixel clusters is counted, and the total beta and gamma counts generated by the decay of three daughter Pb-214, Bi-214 and Po-214 are utilized to reversely push the concentration of the Rn-222, namely:

（1）

in the formula (1), N (. beta. + gamma.) represents the total count of the beta rays and the gamma rays in the measurement time,the concentration of Rn-222 is shown, and K is a proportionality coefficient and is obtained by experiment.

Technical Field

The invention relates to a nuclear radiation measuring technology, in particular to a device and a method for measuring Rn-222 by adopting a CMOS image sensor.

Background

Rn-222 and the daughter are radioactive elements, and internal irradiation is generated on the respiratory system of the human body after inhalation. Therefore, the study of radon measurement methods and improved measurement techniques are very important for radiation protection. In the decay chain of Rn-222, Rn-222 decays to generate Po-218, Po-218 decays to generate Pb-214, then Pb-214 decays to generate Bi-214, and Bi-214 decays to generate Po-214. Wherein the Pb-214, Bi-214 and Po-214 all release beta rays and gamma rays with certain energy when decaying. While CMOS image sensors have a certain response to beta and gamma radiation, it has been proven that CMOS image sensors can detect beta and gamma radiation. Under equilibrium conditions, the number of beta and gamma rays produced by this decay chain is directly proportional to the concentration of Rn-222. For this reason, how to detect beta rays and gamma rays by using the irradiation response of the CMOS, count them, and further, how to back-predict the concentration of Rn-222 by counting is a challenging task, and it is necessary to specially design and manufacture a device for collecting Rn-222 daughter by electrostatic collection method, and to be able to measure the concentration of Rn-222 in a certain carrier gas.

Disclosure of Invention

It is an object of the present invention to overcome the above-mentioned deficiencies of the prior art and to provide an apparatus and method for measuring Rn-222 using a CMOS image sensor.

The technical scheme of the invention is as follows: the device for measuring Rn-222 by adopting the CMOS image sensor comprises a measuring cavity, the CMOS image sensor, a computer, a high-voltage contact, a high-voltage module, a radon chamber, a first electromagnetic valve, a second electromagnetic valve and an air pump.

The cylinder wall of the lower part of the measuring cavity is provided with a first air pipe valve and a second air pipe valve, the CMOS image sensor is installed on an end cover of the measuring cavity and is connected with a computer through a USB wire and used for observing experimental phenomena and processing data, the high-voltage contact is installed on the cylinder wall of the upper part of the measuring cavity and is connected with the high-voltage module through a wire, the first air pipe valve is connected with the first electromagnetic valve through a pipeline, the other end of the first electromagnetic valve is connected with the radon chamber through a pipeline, the second air pipe valve is connected with the second electromagnetic valve through a pipeline, the other end of the second electromagnetic valve is connected with the air pump through a pipeline, and the other end of the air pump is connected with the radon chamber through a pipeline.

The inner wall of the measuring cavity is made of conductive metal, the high-voltage module generates high voltage on the inner wall of the measuring cavity through the high-voltage contact, metal wiring is contained in the CMOS image sensor, low voltage is generated during working, and the high voltage on the inner wall of the measuring cavity and the low voltage of the CMOS image sensor form an electrostatic field.

The further technical scheme of the invention is as follows: the method for measuring Rn-222 by using the device for measuring Rn-222 by using the CMOS image sensor is characterized in that when the measurement is started, a first air pipe valve and a second air pipe valve are opened, the Rn-222 is pumped from a radon chamber through an air pump, enters a measurement cavity through a second electromagnetic valve, and then is sent back to the radon chamber through the first electromagnetic valve by the first air pipe valve to form a closed loop.

During the decay process of Rn-222, Pb-214, Bi-214 and Po-214 generate a certain proportion of beta rays and gamma rays, the beta rays and the gamma rays interact with the CMOS image sensor, charges generated by ionization can be collected by pixels on the CMOS image sensor and form pixel clusters, and under the condition that the decay reaches the equilibrium, the total count of the pixel clusters is proportional to the concentration of Rn-222.

Because the high-voltage module generates high voltage electricity on the inner wall of the measuring cavity through the high-voltage contact and forms an electrostatic field with the low voltage of the CMOS image sensor, radon daughter generated by the decay of Rn-222 in the measuring cavity is collected on the surface of the CMOS image sensor under the action of the electrostatic field, after a period of time, when the decay in the measuring cavity reaches balance, video shooting is completed by the CMOS image sensor within the measuring time, then the video is split into a frame image by software, the number of pixel clusters is counted by the software, and the total beta and gamma counts generated by the decay of three daughter Pb-214, Bi-214 and Po-214 are utilized to reversely deduce the concentration of Rn-222, namely:

（1）

in the formula (1), N (. beta. + gamma.) represents the total count of the beta rays and the gamma rays in the measurement time,the concentration of Rn-222 is shown, and K is a proportionality coefficient and is obtained by experiment.

Compared with the prior art, the invention has the following characteristics:

the device for measuring Rn-222 by using the CMOS image sensor provided by the invention has low cost, obtains the concentration of Rn-222 by measuring the number of beta rays and gamma rays by using the CMOS image sensor, and has high measurement sensitivity.

The detailed structure of the present invention will be further described with reference to the accompanying drawings and the detailed description.

Drawings

FIG. 1 is a schematic structural diagram of the present invention.

Detailed Description

The first embodiment of the invention relates to a device for measuring Rn-222 by using a CMOS image sensor, which comprises a measuring cavity 1, the CMOS image sensor 2, a computer 3, a high-voltage contact 4, a high-voltage module 5, a radon chamber 6, a first electromagnetic valve 7, a second electromagnetic valve 8 and an air pump 9.

The wall of the lower portion of the measuring cavity 1 is provided with a first air pipe valve 1-1 and a second air pipe valve 1-2, the CMOS image sensor 2 is installed on an end cover of the measuring cavity 1, the CMOS image sensor 2 is connected with the computer 3 through a USB line and used for observing experimental phenomena and processing data, the high-voltage contact 4 is installed on the wall of the upper portion of the measuring cavity 1 and connected with the high-voltage module 5 through a lead, the first air pipe valve 1-1 is connected with the first electromagnetic valve 7 through a pipeline, the other end of the first electromagnetic valve 7 is connected with the radon chamber 6 through a pipeline, the second air pipe valve 1-2 is connected with the second electromagnetic valve 8 through a pipeline, the other end of the second electromagnetic valve 8 is connected with the air pump 9 through a pipeline, and the other end of the air pump 9 is connected with the radon chamber 6 through a pipeline.

The inner wall of the measuring cavity 1 is made of conductive metal, the high-voltage module 5 generates high-voltage electricity to the inner wall of the measuring cavity 1 through the high-voltage contact 4, metal wiring (not shown in the figure) is arranged in the CMOS image sensor 2, low voltage is generated during working, and the high voltage of the inner wall of the measuring cavity 1 and the low voltage of the CMOS image sensor 2 form an electrostatic field so as to collect radon daughters.

In the second embodiment, the device for measuring Rn-222 by using the CMOS image sensor is used for measuring Rn-222, when the measurement is started, the first air pipe valve 1-1 and the second air pipe valve 1-2 are opened, the Rn-222 is pumped from the radon chamber 6 through the air pump 9, enters the measurement cavity 1 through the second electromagnetic valve 8, and then is sent back to the radon chamber 6 through the first electromagnetic valve 7 by the first air pipe valve 1-1, so that a closed loop is formed.

During the decay process of Rn-222, Pb-214, Bi-214 and Po-214 generate a certain proportion of beta rays and gamma rays, the beta rays and the gamma rays interact with the CMOS image sensor 2, the charges generated by ionization can be collected by pixels on the CMOS image sensor 2 and form pixel clusters, and under the condition that the decay reaches the equilibrium, the total count of the pixel clusters is proportional to the concentration of Rn-222.

Because the high-voltage module 5 generates high-voltage electricity on the inner wall of the measurement cavity 1 through the high-voltage contact 4 and forms an electrostatic field with the low voltage of the CMOS image sensor 2, radon daughters generated by the decay of Rn-222 in the measurement cavity 1 are collected on the surface of the CMOS image sensor 2 under the action of the electrostatic field, after a period of time, when the decay in the measurement cavity 1 reaches the balance, the CMOS image sensor 2 finishes video shooting in the measurement time, then the video is split into a frame of image by software, the number of pixel clusters is counted by the software, and the total beta and gamma counts generated by the decay of three daughters of Pb-214, Bi-214 and Po-214 are utilized to reversely deduce the concentration of Rn-222, namely:

（1）

in the formula (1), N (. beta. + gamma.) represents the total count of the beta rays and the gamma rays in the measurement time,the concentration of Rn-222 is shown, and K is a proportionality coefficient and is obtained by experiment.