CN113050146A

CN113050146A - Personal direct-reading eye crystal dosimeter and monitoring system thereof

Info

Publication number: CN113050146A
Application number: CN202110253741.0A
Authority: CN
Inventors: 韦丽雯; 胡忠良; 邹益民; 何兴旭; 肖佐诗; 赵永生; 丁泮; 李猛
Original assignee: Hainan Nuclear Power Co Ltd
Current assignee: Hainan Nuclear Power Co Ltd
Priority date: 2021-03-09
Filing date: 2021-03-09
Publication date: 2021-06-29

Abstract

The invention discloses a personal direct-reading eye crystal dosimeter and a monitoring system thereof, wherein the eye crystal dosimeter comprises: the control system comprises a single chip microcomputer, a timing system, a data storing and reading module, a key control module, an energy spectrum measuring module, a display module, an audible and visual alarm and a computer interface, wherein the timing system, the data storing and reading module, the key control module, the energy spectrum measuring module, the display module, the audible and visual alarm and the computer interface are connected with the single chip microcomputer; the monitoring system includes: the eye crystal dosimeter comprises an eye crystal dosimeter, and further comprises a computer and an upper management system which are connected with the eye crystal dosimeter. The personal direct-reading eye crystal dosimeter can directly carry out personal eye crystal dosage direct-reading measurement, and the arranged monitoring system can realize high-efficiency analysis and management of personal eye crystal dosage measurement data, thereby meeting the requirement of comprehensively analyzing the irradiated dosage of a person under a new eye crystal dosage limit value.

Description

Personal direct-reading eye crystal dosimeter and monitoring system thereof

Technical Field

The invention relates to the technical field of personal dosage monitoring, in particular to a personal direct-reading eye crystal dosimeter and a monitoring system thereof.

Background

Compared with the conventional limit value, the dose of the eye crystal specified by the international radiation protection and radiation source safety basic safety standard issued by the International Atomic Energy Agency (IAEA) in 2011 is reduced by nearly one order of magnitude, and the limit value is also brought into the national new standard, so that a new requirement is provided for monitoring and evaluating the exposure dose of the eye crystal during radiation protection work of a nuclear power plant.

At present, the prior art has the following disadvantages:

1. eye crystal thermal release dose monitoring system: the system can obtain the dose only after the personnel are irradiated and the thermoluminescent dose sheet in the dose meter is measured and read by special equipment, the irradiated dose of the eye crystal of the worker cannot be monitored in time, and the occurrence of overdose accidents is prevented in advance.

2. Direct-reading personal dosage monitoring system: most of the monitoring systems can only measure the systemic dosage and do not have the function of monitoring the dosage of the ocular lens.

3. Ophthalmic lens personal dosimeter: the current commercial products only have the function of measuring X and gamma eye lens doses and do not form a monitoring system.

Therefore, there is a need to develop a direct-reading personal dosimeter for monitoring the exposure dose of the eye lens, which can measure the dosage of the eye lens of X, γ, β rays and monitor the dosage of the eye lens.

Disclosure of Invention

The invention aims to provide a personal direct-reading eye crystal dosimeter and a monitoring system thereof, which solve the problem that the prior art has no direct-reading personal dosimeter suitable for monitoring the irradiated dose of an eye crystal, realize the measurement and monitoring of the dose of the eye crystal and prevent the occurrence of overdose accidents.

The technical scheme of the invention is realized as follows:

the personal direct-reading eye crystal dosimeter comprises a power supply module, a high-voltage module, an eye crystal detector and a control system, wherein the control system comprises a single chip microcomputer, and a timing system, a data storing and reading module, a key control module, an energy spectrum measuring module, a display module, an audible and visual alarm and a computer interface which are connected with the single chip microcomputer.

Preferably, the eye crystal detector is from last to having set gradually polytetrafluoroethylene layer, plastics scintillator, organic glass layer and SiPM layer down, SiPM layer electric connection has the amplifier, eye crystal detector both sides are provided with the light shading layer.

Preferably, the polytetrafluoroethylene layer has a thickness of 1.2mm and a density of 2.2g/cm³。

Preferably, the thickness of the plastic scintillator is 0.8 mm.

Preferably, the thickness of the organic glass layer is 3 mm.

The monitoring system of the personal direct-reading eye crystal dosimeter comprises the eye crystal dosimeter, and further comprises a computer and an upper management system which are connected with the eye crystal dosimeter.

Preferably, the computer comprises a communication interface module, a data storage module, an analysis management module and a network interface module.

The invention has the beneficial effects that:

the personal direct-reading eye crystal dosimeter can directly carry out personal eye crystal dosage direct-reading measurement, and the arranged monitoring system can realize high-efficiency analysis and management of personal eye crystal dosage measurement data, thereby meeting the requirement of comprehensively analyzing the irradiated dosage of a person under a new eye crystal dosage limit value.

Drawings

FIG. 1 is a schematic circuit diagram of an ophthalmic crystal dosimeter of the invention;

FIG. 2 is a schematic diagram of the configuration of an ophthalmic lens detector of the present invention;

fig. 3 is a schematic circuit diagram of the monitoring system of the present invention.

In the figure, the device comprises a power supply module 1, a high-voltage module 2, an eye crystal detector 3, a timing system 4, an energy spectrum measuring module 6, a data storing and reading module 7, a single chip microcomputer 8, a computer interface 9, a key control module 10, a display module 11, an audible and visual alarm 12, a polytetrafluoroethylene layer 13, a plastic scintillator 14, an organic glass layer 15, an SiPM layer 16, a light shading layer 17 and an amplifier.

Detailed Description

In order to better understand the technical content of the invention, specific embodiments are provided below, and the invention is further described with reference to the accompanying drawings.

Referring to fig. 1 to 2, the personal direct-reading eye crystal dosimeter comprises a power module 1, a high voltage module 2, an eye crystal detector 3 and a control system, wherein the control system comprises a single chip microcomputer 7, a timing system 4 connected with the single chip microcomputer 7, a data storing and reading module 6, a key control module 9, an energy spectrum measuring module 5, a display module 10, an audible and visual alarm 11 and a computer interface 8.

The power module 1: the device is a 3.7V lithium battery and provides power for the whole eye crystal dosimeter;

the high-voltage module 2: the voltage booster is composed of a boost chip and a temperature sensor, the boost chip converts the voltage of a 3.7V lithium battery into direct current voltage of about 30V, and the gain of the SiPM layer 15 is sensitive to the voltage and the temperature, so that the voltage output by the boost chip is controlled by the singlechip 7 according to the acquired temperature data, and the gain of the SiPM layer 15 keeps a stable value;

eye lens detector 3: the eye crystal detector 3 shown in fig. 2 converts the energy deposited in the incident ray particle into a voltage pulse output;

the timing system 4: a timing chip can be adopted and used for recording time and outputting the current time to the singlechip 7;

energy spectrum measuring module 5: the amplitude measuring device is used for measuring the amplitude of the voltage pulse and converting the amplitude into a spectrum signal;

the data storage module 6: a Flash memory chip can be adopted for storing measured data and can be read by the singlechip 7;

and the singlechip 7: MSP430 singlechip 7 can be used as the central control unit of the eye crystal dosimeter;

computer interface 8: adopting a miniUSB interface for communication;

the key control module 9: two keys are adopted, one is a Mode key and the other is a Set key, and the two keys are used for controlling the operation of the singlechip 7 through the keys;

the display module 10: adopt liquid crystal display to show, the information that can show on the display screen has: dose, dose rate, date, time, dose symbol, dose rate symbol, alarm symbol;

audible and visual alarm 11: the sound and light alarm module 11 is a buzzer, gives an alarm signal through the buzzer under the control of the singlechip 7, and can alarm when an alarm condition (such as exceeding dosage rate) is reached.

Specifically, the eye crystal detector 3 is sequentially provided with a polytetrafluoroethylene layer 12, a plastic scintillator 13, an organic glass layer 14 and an SiPM layer 15 from top to bottom, the SiPM layer 15 is electrically connected with an amplifier 17, two sides of the detector are provided with light shielding layers 16, the thickness of the polytetrafluoroethylene layer 12 is 1.2mm, and the density is 2.2g/cm³The thickness of the plastic scintillator 13 is 0.8mm, and the thickness of the organic glass layer 14 is 3 mm.

The measurement principle of the eye crystal detector of the invention is as follows:

as shown in FIG. 2, the top layer of the ocular lens detector 3 is a 1.2mm thick Teflon layer 12, the Teflon layer 12 is equivalent to 2.6mm tissue material, and the Teflon layer 12 is chosen as the cover layer because Teflon has both an average atomic number close to that of human tissue (relative to other optional materials) and a high density (2.2 g/cm)³) Is the most suitable material.

A plastic scintillator 13 with the thickness of 0.8mm is arranged below the polytetrafluoroethylene layer 12, the distance between the center point of the plastic scintillator 13 and the upper surface of the eye crystal detector 3 is just 3.0mm, and if the attenuation effect of rays in the plastic scintillator 13 is neglected, the absorbed dose in the plastic scintillator 13 can represent the absorbed dose D at the position 3mm below the skin of a human body_p(3) Since the quality factors Q of γ and β are both 1, H_p(3)＝D_p(3)。

The SiPM layer 15 is a silicon photomultiplier, and can convert weak light generated in the plastic scintillator 13 into an electrical signal and amplify the electrical signal, and has the advantages of small volume and low power consumption.

Protocol for measurement with plastic scintillator 13, the method of measurement is by definition:

measuring the deposited dose E in a thin layer of tissue at a position 3mm below the surface of the human body, and dividing the deposited dose by the mass m of the thin layer of tissue to obtain the absorbed dose D_p(3) Since the quality factors Q of γ and β are both 1, H_p(3)＝D_p(3)×1＝D_p(3)。

For the deposition energy E in a layer of tissue in the ocular lens detector 3, the deposition energy E in the layer can be obtained by measuring the deposition energy spectrum in the layer of tissue and then using the following formula:

wherein M represents the maximum number of traces of the measured spectrum, N_iRepresenting the count of the nth trace in the spectrum; w is a_iRepresenting the deposition energy in the scintillator represented by 1 count in the ith pass,

the mass m of a layer of tissue can be obtained by depositing the area, thickness and density of the tissue, i.e. the area is multiplied by the thickness to obtain the volume, and the volume is multiplied by the density to obtain the mass m.

Referring to fig. 3, the monitoring system of the personal direct-reading eye crystal dosimeter comprises the eye crystal dosimeter, and further comprises a computer and an upper management system connected with the eye crystal dosimeter.

A communication interface module: communicating with the eye crystal dosimeter through a USB port;

a data storage module: collecting and storing data monitored by an eye crystal dosimeter;

an analysis management module: analyzing and managing the monitoring data, such as searching the highest instantaneous dosage rate, calculating the average dosage rate and the like;

a network interface module: and the network interface module is communicated with the upper management system, and data is sent according to the requirement of the upper management system.

Principle of the monitoring system:

the eye crystal dosimeter is used for measuring, a matched module on the computer is used for reading, storing, analyzing and the like of data of the eye crystal dosimeter, and the upper management system is used for performing more specialized processing and comprehensive management on the data.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.

Claims

1. The personal direct-reading eye crystal dosimeter is characterized by comprising a power supply module, a high-voltage module, an eye crystal detector and a control system, wherein the control system comprises a single chip microcomputer, and a timing system, a data storage and reading module, a key control module, an energy spectrum measuring module, a display module, an audible and visual alarm and a computer interface which are connected with the single chip microcomputer.

2. The personal direct-reading eye crystal dosimeter of claim 1, wherein the eye crystal detector is provided with a polytetrafluoroethylene layer, a plastic scintillator, an organic glass layer and an SiPM layer from top to bottom in sequence, the SiPM layer is electrically connected with an amplifier, and two sides of the eye crystal detector are provided with light shielding layers.

3. The personal direct-reading eye crystal dosimeter of claim 2, wherein the polytetrafluoroethylene layer has a thickness of 1.2mm and a density of 2.2g/cm³。

4. The personal direct-reading eye crystal dosimeter of claim 2, wherein the thickness of the plastic scintillator is 0.8 mm.

5. The personal direct-reading eye crystal dosimeter of claim 2, wherein the thickness of the plexiglass layer is 3 mm.

6. A monitoring system of a personal direct-reading eye crystal dosimeter, which comprises the eye crystal dosimeter of any one of claims 1-5, and is characterized by further comprising a computer and an upper management system connected with the eye crystal dosimeter.

7. The monitoring system of the personal direct-reading ophthalmic lens dosimeter of claim 6, wherein the computer comprises a communication interface module, a data storage module, an analysis management module, and a network interface module.