37 results about "Radon flux" patented technology

The invention discloses a method for open-loop measurement of a radon exhalation rate by utilizing a total count of 218Po and 214Po. The method comprises the following steps: a radon collection cover is buckled on the surface of a medium to be measured during measurement, clean air with the radon concentration of near zero is continuously pumped from outside by utilizing a pump of a radon measuring apparatus, and the radon exhalation rate can be obtained by measuring a radon concentration change rule in the radon collection cover. According to the conventional static collection method radon measuring apparatus, the change of the radon concentration is obtained by only measuring a daughter 218Po with the decayed radon. As for a medium with low exhalation rate, a radon concentration value in the radon collection cover is low, the count of high-energy alpha particles emitted by 218Po decay is only measured, and the statistical fluctuation is larger due to few counts. According to the invention, the count of high-energy alpha particles emitted by 218Po decay and the count of high-energy alpha particles emitted by 214Po decay in a longer time period are simultaneously measured, and two radon exhalation rates are respectively obtained and are averaged, so that the accurate radon exhalation rate is obtained.

The invention discloses a method and a system for measuring a total release rate of radon on the surface of a medium within a certain time period, and relates to the technical field of nuclear radiation detection. The method comprises the following steps of distributing and sampling; computing an average value of a radon precipitation rate on the surface of a to-be-measured medium in single measurement according to a sampling measurement result; computing the total release rate of the radon in unit area of a to-be-measure region within the certain time period; computing the total release rate of the radon on the surface of the medium within the certain time period. According to the method and the system for measuring the total release rate of the radon on the surface of the medium within the certain time period, disclosed by the invention, a region distribution rule on the surface of the medium can be measured through an activated carbon-gamma energy spectrum method, continuous measurement on the radon precipitation rate representing a measurement point can be carried out by using a radon precipitation rate continuous measurement method based on electrostatic collection, the change rule can be obtained, and a radon precipitation rate measuring instrument is used as a standard for correcting an activated carbon measurement result, so that an accurate average radon precipitation rate value is obtained, and the total release rate of the radon on the surface of the medium within the certain time period is obtained.

The present invention is related to a method and apparatus of radiation processing of a product package in a device having a radiation source, a collimator having a variable aperture, and a turntable, said radiation processing resulting in a point in the product package where the dose is minimal (Dmin point) and a point in said product package where the dose is maximal (Dmax point) comprising the steps of:determining a first value of the collimator aperture, by increasing said aperture from a small value, where the Dmax point is located near the centre of the product package, up to a value where the Dmax point moves near to the centre of a small side of said package's rectangular horizontal cross-section;determining a second value of the collimator aperture, by further increasing the collimator aperture up to a point where the Dmin point moves from a point near the corner of the product package to the centre of said package;processing said package with radiation, the collimator aperture being kept at a constant value comprised between said first and said second value, the turntable being rotated at a variable speed.

A system and a method for an ambient atmosphere ion thruster having a pair of permeable electrical members for accelerating ambient atmosphere ions which enter the thruster due to a craft's relative velocity. Neutral ambient atmosphere molecules in the intake mass flux may also be ionized and subsequently accelerated by the pair of permeable electrical members. Acceleration of any entering mass comprises an exhaust mass flux which then produces a net thrust. Such net thrust is then vectored by configuring and orienting the thrusters for imparting axial and lateral accelerations as well as pitch, yaw, and roll controls. The present invention is operational in proximity to any celestial body having a sensible atmosphere during a portion of the free trajectory or during orbiting at altitude. Useful net thrust is thereby produced without need for carrying reaction mass onboard a spacecraft.

A device and method for adjusting radon exhalation rate and effective decay constant by using a radon chamber, one end of the filter membrane in the device is connected to the measuring room of the measuring instrument through a pipeline, the other end of the filter membrane is connected to a drying pipe through a pipeline, and the other end of the drying pipe is passed through The pipeline is connected to the radon collecting hood, one end of the pump is connected to the measuring chamber of the measuring instrument through the pipeline, the other end of the pump is connected to the radon collecting hood through the pipeline, the gas outlet joint and the air inlet joint are respectively installed on the dense material plate, and the gas outlet joint passes through the pipeline It is connected with an adjustable micropump, the other end of the adjustable micropump is connected with a flowmeter through a pipeline, the other end of the flowmeter is connected with a radon chamber through a pipeline, and the other end of the radon chamber is connected with an air inlet joint through a pipeline. The measurement method includes the conventional radon exhalation rate measurement process and the process of using a radon chamber to adjust the radon exhalation rate and effective decay constant of the radon exhalation rate standard device. By adjusting the flow rate of the adjustable micropump in the device, the radon exhalation rate can be adjusted and the effective decay constant.

The invention discloses a method and device for measuring the emanation medium radon exhalation rate in an open-loop mode. According to the method, the measurement of the radon exhalation rate is carried out by using the device. The device comprises a radon measuring instrument and a test column used for containing a to-be-tested emanation medium, a gas collecting cover is arranged above the testcolumn, the gas inlet of the radon measuring instrument is communicated with the gas collecting cover through an air pipe, the gas outlet of the radon measuring instrument is communicated with an external environment, a hole communicated with the external environment is formed in the upper surface of the gas collecting cover, a gas pressure equalizing chamber is arranged below the test column, thegas pressure equalizing chamber is connected with a gas pump through the gas pipe, and a flow regulator is arranged on the gas pipe between the gas pressure equalizing chamber and the gas pump. The method has the advantages that the free diffusion of the radon on the surface of the medium is considered, and the influence of the seepage effect is also considered. In addition, the device can accurately measure the radon exhalation rate of the surface of the medium in a short time.

An open-loop type quick measurement method of radon exhalation rate includes two measurement modes. In the first measurement mode, multiple shorter cycles which respectively last for 1-20 minutes are measured after a radon collection case is capped on the surface of a to-be-measured medium so that the radon concentration sequence is acquired, the measurement data of each cycle are approximately regarded as the concentration 218Po of the center point of each measurement cycle, and then the radon exhalation rate can be acquired by means of non-linear data fitting. In the second measurement mode, a longer cycle which lasts for 20-200 minutes is measured after the radon collection case is capped on the surface of the to-be-measured surface, and the radon exhalation rate can be solved by the aid of the measurement value of the longer measurement cycle according the formulas (14) and (15). The open-loop type quick measurement method of the radon exhalation rate is quick in measurement, and the radon exhalation rate can be obtained by calculation according to the measurement data before the radon in the radon collection case balances.

The invention relates to the technical field of radon measurement, and provides a radon exhalation rate measuring instrument which comprises a radon exhalation cover, a radon measurement chamber and a detector. The radon measurement chamber is arranged in the radon exhalation cover, a collection electric field is formed because of a voltage difference between the detector and the radon measurement chamber, and radon daughters generated after radon decay carry positive charges and tend to one side with low potential energy of the electric field, so that the radon exhalation rate of the surface of an object to be measured in a natural state is measured.

The device and method for adjusting the radon exhalation rate and the effective decay constant of the radon exhalation rate standard device, one end of the filter membrane in the device is connected with the measuring chamber of the measuring instrument through a pipeline, the other end of the filter membrane is connected with a drying pipe through a pipeline, and the other end of the drying pipe is One end is connected to the radon collecting hood through a pipeline, one end of the pump is connected to the measuring chamber of the measuring instrument through a pipeline, and the other end of the pump is connected to the radon collecting hood through a pipeline. It is connected to the adjustable micropump through the pipeline, the other end of the adjustable micropump is connected to the flowmeter through the pipeline, the other end of the flowmeter is connected to the flow-type radon source through the pipeline, and the other end of the flow-type radon source is connected to the inlet joint through the pipeline . The measurement method includes the conventional radon exhalation rate measurement process and the process of adjusting the radon exhalation rate and effective decay constant of the radon exhalation rate standard device. By adjusting the flow rate of the adjustable micropump in the device, the radon exhalation rate and effective decay constant can be adjusted. .

The invention relates to a method for measuring the precipitation rate of radon, which comprises a measuring step and a calculating step. A radon collection cover is covered on the surface of a medium to be tested or the medium is put in the radon collection cover, a group of radon concentration data is obtained after measuring at time intervals, and the radon concentration data obtained by measure are fitted in a nonlinear way to obtain the precipitation rate of radon according to a formula (9); or measure data after 20 min are fitted in a nonlinear way to obtain the precipitation rate of radon according to a formula (10).

The invention discloses a method and a device for measuring a radon exhalation rate on a medium surface. The measuring method comprises a measuring process and a calculating process. The measuring method comprises the following steps: during measurement, inversely covering a radon accumulation chamber on the surface of a medium to be measured; connecting a sealed measuring chamber with the radon accumulation chamber to form a loop; after collecting a certain time period of 5 minutes, turning on an air pump to mix the radon in the radon accumulation chamber and the measuring chamber at a smallflow rate less than 3L / min for 5 minutes, wherein at this time, the radon concentration in the measuring chamber is the radon concentration in the radon accumulation chamber at the time T; repeatedlymeasuring the radon concentration in the radon accumulation chamber to obtain a group of data of radon concentration in the radon accumulation chamber at equal time intervals by taking T which is greater than or equal to 10 minutes as a period; and solving the radon exhalation on the surface of the medium to be measured according to a theoretical formula. The measuring device consists of the radon accumulation chamber, the air pump, the measuring chamber, a secondary instrument and a drying pipe, wherein one end of the air pump is connected with the radon accumulation chamber, while the otherend is connected with the measuring chamber through a pipe; one end of the drying pipe is connected with the radon accumulation radon through a pipe, while the other end is connected with the measuring chamber through a pipe; and the secondary instrument is connected with the measuring chamber.

The invention relates to a method, a device and a system for rapidly open-loop measuring the exhalation rate of radon without a flow meter. The method for fast open-loop measurement of radon exhalation rate without a flow meter comprises steps: S1, pre-processing: the radon collecting hood is buckled on the medium to be measured, and the outside air enters from the radon collecting hood air inlet and is connected with the radon collecting hood Air mixing in the interior; S2, measurement: use a measuring instrument to measure the radon concentration, obtain measured values ​​multiple times, and generate a sequence of measured values ​​according to time sequence; S3, calculate: use the sequence of measured values ​​to perform data fitting using the no-flow parameter formula, Get the radon exhalation rate. The method, device and system for rapid open-loop measurement of radon exhalation rate without a flow meter provided by the present invention, through analyzing the radon concentration rising curve data in the radon collecting hood collection room, the reference variables and simplified calculation formulas are reduced, and the results are accurate .

The invention relates to a method for measuring radon emanation rate by adopting a two-stage method, in particular to a method for measuring radon concentration variation in a radon collecting cover by adopting an electrostatic collecting method to obtain the radon emanation rate. The method comprises a measuring process and a calculating process, radon concentration in two longer periods in the radon collecting cover are measured, and the radon emanation rate can be solved by utilizing formulas (2) and (3), or the formulas (4) and (5), or the formulas (6) and (7), or the formulas (8) and (9)or the formulas (10) and (11); radon concentration in three longer periods in the radon collecting cover are measured, a first measuring period is 20 minutes, data of a second measuring period and a third measuring period are utilized, and the radon emanation rate can be solved by utilizing the formulas (13) and (14), or the formulas (15) and (16), or the formulas (17) and (18), or the formulas (19) and (20), or the formulas (21) and (22), or the formulas (23) and (24) or the formulas (25) and (26). The measuring and calculating method and the measuring device are simple and are convenient tooperate, and rapid radon emanation rate measuring requirement is met.

The invention, which relates to the technical field of nuclear radiation detecting, provides a synchronous setting apparatus and method of a radon precipitating rate measuring instrument. The synchronous setting apparatus comprises a filling block connected to the inner wall of a radon collection room of a radon precipitating rate measuring instrument detachably and a rapid radon precipitating rate setting unit connected in series to an air inlet pipe or an air return pipe. A radon precipitating rate value measured by the rapid radon precipitating rate setting unit is used as a standard for setting of the radon precipitating rate measuring instrument. To be specific, the rapid radon precipitating rate setting unit carries out equivalent processing on a changing radon concentration by usinga difference method; and on the basis of a corresponding scale factor value and alpha particle counting data collected by a detector during the measuring process, a radon concentration value of a next measuring cycle is calculated by combining a radon concentration value of a previous measuring cycle; The radon precipitating rate setting speed is fast; the time of radon precipitating rate measuring instrument setting is reduced substantially; the deviation caused by too long time during the setting process is reduced; and the setting value accuracy is enhanced.

According to a method for continuously measuring the radon exhalation rate according to the change of a leakage coefficient and a back-diffusion coefficient, before the leakage coefficient and the back-diffusion coefficient are not changed, the effective decay constant is firstly measured, and the radon exhalation rate is directly calculated through the effective decay constant. When rainfall or geological conditions are changed, and the leakage coefficient and the back-diffusion coefficient are changed, each measurement period is set to be 2 to 60 minutes, n measurement periods are set as one group, m groups are continuously measured, m is an even number, the flow rate of the pump is L1 when the first, third, fifth,... and (m-1) th groups are measured, the flow rate of the pump is L2 when the second, fourth, sixth,... and m th groups are measured, and the difference between L1 and L2 is more than 20%; and the radon exhalation rate and the effective decay constant are calculated through a formula by using the data of the first and second groups, the data of the third and fourth groups,..., and the data of the m-1 and m groups. According to the method, after the leakage coefficient and the back-diffusion coefficient are changed, the accurate radon exhalation rate and the effective decay constant can still be obtained, and the calculation precision of the radon exhalation rate is improved.

The invention discloses a closed-loop method and device for measuring a radon exhalation rate of a gas emitting medium. The method comprises the following steps that (1) a gas pump is opened, and theflow rate entering a gas equalizing chamber is controlled to be Q through a flow regulator; the radon concentration C0 in the external environment measured by a radon measuring instrument is taken asthe radon concentration C0 of a gas collecting hood at zero time t0; when the radon concentration in the gas collecting hood is measured, the radon concentrations C1, C2,... and Cn ( n>=5) is recordedat this time in sequence at the same time interval delta T; and (2) the solution of differential equation (shown in the description) is fitted with the above measured values, and then radon exhalation rate J is calculated. The radon exhalation rate and equivalent decay constant can be obtained by the method before the radon concentration is balanced, the closed-loop method and device for measuring the radon exhalation rate of the gas emitting medium have the advantages of short time and accurate calculation.

The invention relates to fusion reactor tritium generating cladding neutron measuring. Helium cooling solid breeding agent tritium generating cladding neutron flux and spectrometry measuring system includes packaging foil pneumatic transmitting activation analysis subsystem which includes activation foil and pneumatic transmitting device. The activation foil is set in the measuring tube connectedwith operating station through cooling layer and biological shielding layer. The operating station is set helium cooling circuit and connected with helium gas dynamic force union station and HPGe measuring station connected with electronics and data gaining system. The solid breeding agent tritium generating cladding is also set micro-fission chamber combination detector and natural diamond neutron energy spectrum detector which are connected with operating station through current sensitive preamplifier and charge sensitive preamplifier, which is connected with electronics and data gaining system.

The invention discloses a method for estimating the radon precipitation rate on the surface of an in-situ leaching and mining uranium evaporation pond, comprising the following steps: establishing a theoretical calculation formula based on the active diffusion and seepage passive diffusion of radon in a medium; As a result, the estimation results are revised based on the source term inversion method of BP neural network. This method establishes the theoretical calculation formula of radon precipitation rate, comprehensively considers the active diffusion of radon in the medium and the passive diffusion of seepage, and uses the BP neural network to learn the monitoring data to establish the source term inversion method. The calculation results of the estimation method are revised, and the method fills the gap of the research and realizes the accurate estimation of the radon precipitation rate.