A kind of method and device that gas concentration in the emanometer measuring chamber is mixed
Technical field
The present invention relates to a kind of nuclear radiation detection technology, particularly a kind of electrostatic collection method that is used for is measured
222Rn/
220Method that during Rn concentration gas concentration in the emanometer measuring chamber is mixed and device.
Background technology
Radon pumps into measuring chamber after falling daughter through membrane filtration in the air ambient, and measuring chamber is generally semisphere or cylindrical, and the alpha detection device is housed in the centre, between detector and measuring chamber, is added with the negative high voltage electric field of 50V-100V/cm.Radon in the measuring chamber is with the radon daughter of the newborn positively charged that decays, and it is collected into the surface of detector under the effect of electrostatic field, calculates radon concentration through the α particle measurement that radon daughter is emitted.Current RAD7 is to use electrostatic collection method emanometer device the most widely; The structure of its measuring chamber is as shown in Figure 1; It comprises the columniform cylindrical shell 1 of a sealing, and the top of cylindrical shell 1 is a plane, and the bottom of cylindrical shell 1 is an arc; On the cylindrical barrel of cylindrical shell 1, be provided with a gas inlet-outlet 3, be provided with a gas inlet-outlet 2 in the bottom of cylindrical shell 1.All
220Rn/
222Rn measurement of concetration theoretical model is all thought
220Rn/
222Rn is instantaneous even diffused in measuring chamber, and principle obtains thus
220Rn/
222Rn concentration.Because
220The Rn half life period has only 55 seconds, and aerial diffusion length has only 2.9cm, for the big measuring chamber like RAD7, under slower flow velocity, be certain to occur the even phenomenon of density unevenness in the measuring chamber, and measuring chamber structure as shown in Figure 1 like this makes the gas outlet
220Rn concentration is higher than the mean concentration in the measuring chamber, promptly in the measuring chamber
220Rn concentration is lower than theoretical value.Some documents are mentioned, and utilize RAD7 to measure
220Rn concentration ratio reference value low 30%.Utilizing short time interval measurement to change at a high speed
222During Rn concentration, also can be owing to the bigger phenomenon of measured value deviation appears in this effect.For suppressing this effect, can adopt the method for dwindling the measuring chamber volume, but can cause detection efficiency to reduce, the result that statistic fluctuation increases.In general use the measuring chamber of larger volume still to have advantage.Also can adopt the method that improves sampling flow, can utilize turbulence effect to make in the measuring chamber
220Rn/
222Rn mixes certainly, but this can make the measurement point air-flow take place than about-face again, also can produce big measuring error.
Summary of the invention
The objective of the invention is to overcome the above-mentioned deficiency of prior art and provide a kind of electrostatic collection method that is used for to measure
222Rn/
220Method that during Rn concentration gas concentration in the emanometer measuring chamber is mixed and device.
Technical scheme of the present invention is: a kind of electrostatic collection method that is used for is measured
222Rn/
220The method that during Rn concentration gas concentration in the emanometer measuring chamber is mixed, it is in existing measuring chamber, to establish a gas agitation mixing arrangement, utilizes the gas agitation mixing arrangement with in the measuring chamber
220Rn/
222Rn mixes, and guarantees in the measuring chamber
220Rn/
222Rn concentration is near theoretical value.
Another technical scheme of the present invention is: on the cylindrical barrel of the bottom of existing measuring chamber and measuring chamber cylindrical shell, establish the gas inlet-outlet more than three; Gas inlet-outlet communicates with the inner chamber of measuring chamber cylindrical shell; Utilize gas on measuring chamber a plurality of gas inlet-outlet flow to outflow; In measuring chamber, produce air-flow, thereby utilize the effect of air-flow to make in the measuring chamber
220Rn/
222Rn mixes, and guarantees in the measuring chamber
220Rn/
222Rn concentration is near theoretical value.
In order to make in the measuring chamber
220Rn/
222It is more even that Rn mixes, in the above-mentioned measuring chamber that has a plurality of gas inlet-outlet, establish a gas agitation mixing arrangement, utilizes the gas agitation mixing arrangement with in the measuring chamber
220Rn/
222Rn further mixes.
The present invention also provides a kind of electrostatic collection method that is used for to measure
222Rn/
220The device that during Rn concentration gas concentration in the emanometer measuring chamber is mixed, its technical scheme is: a kind of employing electrostatic collection method is measured
220Rn/
222The measuring chamber of Rn concentration; It comprises the columniform cylindrical shell of a sealing; The top of cylindrical shell is a plane, and the bottom of cylindrical shell is an arc, on the cylindrical barrel of cylindrical shell, is provided with a gas inlet-outlet; Be provided with a gas inlet-outlet in the bottom of cylindrical shell, two gas inlet-outlet communicate with the inner chamber of measuring chamber cylindrical shell.In order to make in the measuring chamber cylindrical shell
220Rn/
222Rn concentration mixes, and the curved bottom in the measuring chamber cylindrical shell is provided with a gas agitation mixing arrangement.Described gas agitation mixing arrangement is that a hollow gas that is installed in measuring chamber cylindrical shell inner bottom part gas inlet-outlet mixes dish, and this hollow gas mixes dish and is made up of hollow air-guide disk that is installed in measuring chamber cylindrical shell inner bottom part and the wireway that is installed on the hollow air-guide disk.Wireway is the hollow tubular of a upper end closed lower ending opening, on the wireway tube wall, is provided with row's gas port.At the wireway that is provided with at least on the hollow air-guide disk more than two, the gas port on every wireway is arranged along a direction.
After air-flow gets into from the hollow air-guide disk; Get into wireway again; Eject with respect to air intake opening CW or counter clockwise direction then; Because the air-flow reacting force makes that be located at wireway on the hollow air-guide disk drives the hollow air-guide disk with respect to air intake opening counterclockwise or the CW rotation, make in the measuring chamber
220Rn/
222Rn mixes.Wireway adopts insulating material, to reduce the influence to electrostatic field as far as possible.
Described gas agitation mixing arrangement also can be for being installed in the fan in the measuring chamber cylindrical shell.Utilize the wind-force of fan to mix to make in the measuring chamber cylindrical shell
220Rn/
222Rn mixes.Fan blade is less, adopts insulating material, to reduce the influence to electrostatic field as far as possible.
The further technical scheme of the present invention is: a kind of employing electrostatic collection method is measured
220Rn/
222The measuring chamber of Rn concentration; It comprises the columniform cylindrical shell of a sealing; The top of cylindrical shell is a plane, and the bottom of cylindrical shell is an arc, on the bottom of cylindrical shell and cylindrical barrel, is provided with the gas inlet-outlet more than three; Gas inlet-outlet communicates with the inner chamber of measuring chamber cylindrical shell, utilizes the air-flow effect to make in the measuring chamber
220Rn/
222Rn mixes.
For the 220Rn/222Rn in the measuring chamber is further mixed, in measuring chamber, increased a gas agitation mixing arrangement.
The present invention compared with prior art has following characteristics: this measuring chamber has solved measurement
220Rn concentration and utilize short time interval measurement to change at a high speed
222During Rn concentration, because traditional measurement is indoor
220Rn/
222The Rn density unevenness is even, makes the gas outlet
220Rn/
222Mean concentration is inconsistent in Rn concentration and the measuring chamber, causes the bigger problem of measuring error.
Below in conjunction with accompanying drawing and embodiment the present invention is further described.
Description of drawings
Accompanying drawing 1 is measured for the existing electrostatic collection method that adopts
220Rn/
222The measuring chamber structural representation of Rn concentration;
Accompanying drawing 2 mixes the measuring chamber structural representation of dish for band hollow gas provided by the invention;
Accompanying drawing 3 is the air-guide disk structural representation with two wireways;
Accompanying drawing 4 is the vertical view of accompanying drawing 3;
The measuring chamber structural representation that accompanying drawing 5 mixes for band fan provided by the invention;
Accompanying drawing 6 is many gas inlet-outlet measuring chamber structural representation provided by the invention.
Embodiment
Embodiment one, a kind of electrostatic collection method that is used for are measured
222Rn/
220The method that during Rn concentration gas concentration in the emanometer measuring chamber is mixed, it is in measuring chamber, to establish a gas agitation mixing arrangement, utilizes the gas agitation mixing arrangement with in the measuring chamber
220Rn/
222Rn mixes, and guarantees in the measuring chamber
220Rn/
222Rn concentration is near theoretical value.
Its measuring chamber is shown in accompanying drawing 2, accompanying drawing 3, accompanying drawing 4; It comprises the columniform cylindrical shell 1 of a sealing; The top of cylindrical shell 1 is a plane, and the bottom of cylindrical shell 1 is an arc, on the cylindrical barrel of cylindrical shell 1, is provided with a gas inlet-outlet 3; Be provided with a gas inlet-outlet 2 in the bottom of cylindrical shell 1, gas inlet-outlet 3 communicates with the inner chamber of measuring chamber cylindrical shell 1 with gas inlet-outlet 2.In order to make in the measuring chamber cylindrical shell 1
220Rn/
222Rn concentration mixes; In the gas inlet-outlet 2 of measuring chamber cylindrical shell 1 inner bottom part, be provided with a hollow gas and mix dish 4, this hollow gas mixes dish 4 and is made up of the hollow air-guide disk 4-1 that is installed in measuring chamber cylindrical shell 1 inner bottom part and two wireway 4-2 that are installed on the hollow air-guide disk 4-1.Wireway 4-2 is the hollow tubular of a upper end closed lower ending opening, on wireway 4-2 tube wall, is provided with row's gas port 4-2-1.Two wireway 4-2 are located on the same axis, and the gas port 4-2-1 on every wireway 4-2 arranges along a direction.
In the present embodiment, also three or four wireway 4-2 can be installed on hollow air-guide disk 4-1, three or four wireway 4-2 are distributed on the hollow air-guide disk 4-1, and the gas port 4-2-1 on every wireway 4-2 tube wall arranges along a direction.
Embodiment two, a kind of electrostatic collection method that is used for are measured
222Rn/
220The method that during Rn concentration gas concentration in the emanometer measuring chamber is mixed, it is in measuring chamber, to establish a gas agitation mixing arrangement, utilizes the gas agitation mixing arrangement with in the measuring chamber
220Rn/
222Rn mixes, and guarantees in the measuring chamber
220Rn/
222Rn concentration is near theoretical value.
Its measuring chamber is shown in accompanying drawing 5; It comprises the columniform cylindrical shell 1 of a sealing; The top of cylindrical shell 1 is a plane, and the bottom of cylindrical shell 1 is an arc, on the cylindrical barrel of cylindrical shell 1, is provided with a gas inlet-outlet 3; Be provided with a gas inlet-outlet 2 in the bottom of cylindrical shell, gas inlet-outlet 3 communicates with the inner chamber of measuring chamber cylindrical shell 1 with gas inlet-outlet 2.In order to make in the measuring chamber cylindrical shell 1
220Rn/
222Rn concentration mixes, and the curved bottom in the cylindrical shell 1 of measuring chamber is provided with a fan 5, utilizes the wind-force of fan 5 to mix and makes the 220Rn/222Rn in the measuring chamber cylindrical shell mix.Described fan 5 blades are less, adopt insulating material, to reduce the influence to electrostatic field as far as possible.
Embodiment three, a kind of electrostatic collection method that is used for are measured
222Rn/
220The method that during Rn concentration gas concentration in the emanometer measuring chamber is mixed; On the cylindrical barrel of the bottom of measuring chamber and measuring chamber cylindrical shell, establish the gas inlet-outlet more than three; Gas inlet-outlet communicates with the inner chamber of measuring chamber cylindrical shell; Utilize gas on measuring chamber a plurality of gas inlet-outlet flow to outflow, in measuring chamber, produce air-flow, thereby utilize the effect of air-flow to make in the measuring chamber
220Rn/
222Rn mixes, and guarantees in the measuring chamber
220Rn/
222Rn concentration is near theoretical value.
Its measuring chamber is shown in accompanying drawing 6, and it comprises the columniform cylindrical shell 1 of a sealing, and the top of cylindrical shell 1 is a plane; The bottom of cylindrical shell 1 is an arc; Be provided with a gas inlet-outlet 2 in the bottom of cylindrical shell 1, on the cylindrical barrel of cylindrical shell 1, be provided with two exhaust body gateways, every row is provided with three gas inlet-outlet 3; Gas inlet-outlet 2, gas inlet-outlet 3 communicate with the inner chamber of measuring chamber cylindrical shell 1, utilize the air-flow effect to make in the measuring chamber
220Rn/
222Rn mixes.
In order to make in the measuring chamber
220Rn/
222Rn further mixes, and in the measuring chamber of present embodiment, increases a gas agitation mixing arrangement, and this gas agitation mixing arrangement can be that the hollow gas among the embodiment one mixes dish 4, also can be the fan 5 among the embodiment two.