KR910010089B1 - Process and apparatus for measuring surface distribution of charged particle emitting radionuclides - Google Patents

Abstract

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Description

Method and apparatus for measuring the surface distribution of radionuclides radiating charged particles

1 is a cross-sectional view showing the placement of electrodes and the location of a typical raw material portion in a planar detector having five zone position measuring chambers, a protocol multi-wire proportional chamber, an optional absorber and another multi-wire proportional chamber in accordance with the present invention.

2 is a cross-sectional view showing the placement of electrodes and the location of a typical raw material portion in a planar detector having a five-position positioning chamber, an absorber and a second five-position positioning chamber in accordance with the present invention.

3 is a cross-sectional view showing the placement of electrodes and the location of a typical raw material portion in a planar detector of a scintillator with a five-position positioning chamber, a protocol multiple wire proportional chamber, and a photoconverter in accordance with the present invention.

4 is a schematic illustration of typical radiation paths, measurements made by detectors and methods of estimating radiation origin coordinates and error measurements by scattered radiation paths in accordance with the principles of the present invention.

5 is a block diagram of a signal processing circuit for performing calculations necessary to estimate the radiation origin coordinates in accordance with the present invention.

6 is a view showing an apparatus of a detector including a readout circuit and a selection rejection coefficient inside a sealed container according to the present invention.

7 is a block diagram showing main elements of a data acquisition device incorporating a detector and a signal processing circuit according to the present invention.

* Explanation of symbols for the main parts of the drawings

1: raw material 2: airtight window

3: deposition area 4,42: amplification area

5,43: Transmission area 7,8,11,12,15,16,45,46: Detection area

9,61,63: absorbers 26,32,36,56: multi-wire proportional grid electrode

62,64,77: scintillator 62A, 64A, 78: photoconverter

81: detector 87: reading circuit

88: signal processing circuit 89: matching and control circuit

90: data collection processor 91A: multi-channel counter

FIELD OF THE INVENTION The present invention generally relates to a system for measuring the spatial distribution of radionuclides that emit charged particles at the surface portion of a substance, and more specifically, to a method for precisely measuring the emission of charged particles from a surface, and to a relatively broad A device for providing a charged particle emission distribution within a minimum exposure time over a surface area in a high resolution digital image.

At the surface area of a substance, there are several ways to measure the detailed distribution of radionuclides that emit charged particles. Some of these methods deal with a relatively large surface area of up to 1/4 square meter (m 2). One example of such a method is mapping the concentration of p-32 (ie, phosphorus-32) label compounds in thin polyacrylamide gels. In the past, various approaches have been adopted for this measurement problem.

Radiographs perform simultaneous high resolution recording over large areas. However, the photographic film is relatively sensitive to strong beta radiation and its exposure range is limited, so further processing is required for its development and reading, and during background recording, the film is chemically blurred to record the source of radiation. Done. Intensifying screens are sometimes used to improve the sensitivity of photographic films, but such reinforcing screens degrade spatial resolution.

In another approach, for example, various scanning detectors such as gas ionization detectors, scintillators or other solid state detectors are used. Some of these can only detect one point at a time, but some can record only one line or small area. By the way, these scan detectors require a relatively long time to handle an area larger than the area they can detect.

In addition, a segment type detector may be configured by using a plurality of different types of scan detectors. Both the former scan detector and the latter segmented detector induce boundary effects, mechanical distortions and artifacts in their measurement distribution.

Another approach uses a wide range detector. By the way, it has proved that high-resolution solid-state devices, such as a multi-channel plate, are difficult in large sized structure. Existing techniques, including gas ionization detectors, do not provide high spatial resolution, especially for strong beta radiation.

Accordingly, the main object of the present invention is to directly measure the surface distribution of radionuclides radiating charged particles, as well as to resolve the spots of radionuclides concentrated at very fine distances with high spatial accuracy. It is intended to provide a device and method.

A second object of the present invention is to efficiently measure the radionuclide distribution over a large surface area within a short time after radiation is emitted.

A third object of the present invention is to measure radionuclide distribution with high beta radiation, such as p-32, at high resolution over a wide area.

A fourth object of the present invention is to quantitatively measure radioactivity in a wide dynamic range so that low concentration radioactivity can be measured in the presence of high concentration radioactivity.

Various radiation detectors based on proportional amplification ionization in gas have been developed. In most of these, electrons by primary ionization, which are inevitably generated due to the arrangement of the strong electric field, move toward one or more thin wires or conductive fibers. The strong electrostatic field at the wire or fiber surface area causes these primary electrons to collide strongly with the gas electrons and stop further generation of electrons in the controlled avalanche. The resulting charge signal is written to the electronic circuit. The operating conditions can be adjusted so that the amplitude of the electronic signal is proportional to the amount of primary ionization.

The multi-wire proportional grid is a kind of sensing element in a positioning ionization detector based on proportional amplification in gas. Such a grid is an electrode consisting of thinly spaced thin wires or conductive fibers. This grid is embedded in a suitable gas mixture and a strong electrostatic field to form a position measurement chamber. As ionization occurs in this localization chamber, a localized group of primary electrons is generated, each of which is attracted to the wires of the proportional grid. As the electrons approach the surface of each wire, they generate local avalanche, providing a measurable charge signal. By confirming the wires from which these signals are generated or by calculating the position centers of the signals on several wires, the center position of the primary ionization group is measured in one dimension of the grid surface. Parallel grids adjacent to the multiwire proportional grid provide charge signals induced through electrostatic coupling. Two-dimensional position measurement can be obtained by using an induced signal of an adjacent electrode.

Positioning ionization detectors based on proportional amplification in a gas consist of a gas container consisting of one or more position measuring chambers each comprising a multi-wire proportional grading. Suitable structures, components, gas mixtures, dunning methods and operating conditions for these types of detectors are known in the art. These are disclosed in US Pat. Nos. 3,772,521 and 3,786,270 and the following papers.

(1) co-authored by G. Charpak, R. Bouclier, T. Bressani, J. Favier and C. Zupanci, ″ Use of a multi-wire proportional counter for the selection and localization of charged particles ″, nuclear instruments and methods 62: 262-268 (1968).

(2) Co-authored by G. Charpak, P. Bouclier, T. Bressani, J. Faver and C. Zupanci, ″ Proportional Multichamber Reading Device ″, Nuclear Instruments and Methods 65: 217-220 (1986).

(3) Co-authored by G. Charpak, D. Rahm and H. Steiner, ″ Development of the Operation of Multiple Wire Proportional Chambers ″, Nuclear Instruments and Methods 80: 13-34 (1970).

Positioning ionization detectors based on proportional amplification in gases have very high levels of beta radiation for radionuclides. With appropriate readout circuits, all beta radiation incorporated into the sensing volume can be counted. Such detectors have poor spatial resolution except low energy radiation. This is because the beta energy passes through the gas and crosses the long distance, leaving an extended track of ionization along the path. Planar multi-wire proportional chambers produce significant errors in parallax when measuring the wide-angle radiation path with respect to the normal of the grid.

In view of this problem, a multilevel avalanche yarn has been constructed. This is a gas capacity having a very strong electrostatic field defined by additional electrodes parallel to the multi-wire proportional grid to the multi-wire proportional chamber. An avalanche multiplication of ionization occurs in the entire volume where the strong electric field is located, and the amplified ionization drifts into a multi-wire proportional grid via a grid or mesh electrode so that ionization is detected in this multi-wire proportional grid. That is, the multi-wire proportional chamber primarily detects the ionization generated in the strong static field capacity of the opposite side of the multi-wire proportional grid. When the raw material surface is exposed to a detector gas whose strong capacitance is in contact with an external electrode, the detector detects ionization mainly occurring in the gas with a thin layer adjacent to the raw material surface. This reduces the parallax error.

Suitable structures, components, gas mixtures, reading methods and operating conditions for multistage avalanche chambers are described in the following paper.

(4) co-authored by G. Petersen, G. Charpak, G. Melchart and F. Sauli, ″ Multistage Avalanche's Nuclear Instrument and Method for Detectors of Radiation Chromatography Imaging 176: 239-244 (1980).

As development progressed, multistage avalancils faced significant limitations in recording the distribution of beta radiation. That is, since the multi-stage avalanche chamber may detect even ionization of the sensing gas layer far from the radiation source, resolution is degraded for stronger beta radiation. This multistage avalanche chamber must operate at precisely controlled electric field strength, and thus be sensitive to the resulting electrostatic field distortion by contacting or approaching the surface of the raw material. This multistage avalanche yarn responds to large changes in very few primary electrons and thus generates signals of a wide range of amplitudes. In addition, such multistage avalanche chambers require the introduction of a potential contaminant material into the detector gas, while requiring a high purity detector gas for stable operation.

An important point in the origin measurement of strong charged particle radiation is the expansion path of radiation. The measuring method of the present invention uses a detector capable of detecting (1) ionization according to the radiation path of charged particles, (2) reacting radiation from the actual area of the surface of the raw material material, and (3) Construct a separate detector element for measuring the center of ionization at least at two positions, (4) estimate the path direction using a straight line passing through the measurement positions, and (5) use the direction of the path (a) Adjust the position measurement so that the radiation origin is closest to the protruding position of the surface of the raw material, (b) limit the emission record for radiation with path angles within acceptable limits, or (c) provide both coordinate control and acceptance criteria. will be. Orientation is made with the angle of projection of the normal to the surface of the raw material. These directional measurements, coordinate adjustments, and acceptance criteria consist of a projection angle to the normal of the surface of the raw material. These directional measurements, coordinate adjustments and acceptance criteria can be applied to one or two coordinates of the raw material surface.

The apparatus of the present invention is a radioactive imaging apparatus configured to obtain a distribution of radionuclides that emit charged particles at a position proximate to a surface of a raw material. Based on multiple proportional chamber gas ionization detectors. The detector operates in counting mode, ionization signal recording mode, in which the ionization center at at least two positions along the radiation path is calculated from the recorded ionization signal, and in the mode of estimating the coordinates at the origin of each radiation from their measurements. do. Most of them are easily constructed with planar raw material surfaces, but such detectors can also be configured for simple curved raw material surfaces. Such devices are particularly useful on strong beta releases and can be used for other particle and low energy radiations, even if composed of low pressure, low density gas constituents.

The data acquisition subsystem of the device constructed by the present invention obtains the radionuclide distribution at the surface portion of the raw material from many charged particle radiation origin coordinates. This is done by counting the estimated coordinates of the radiation contained within the boundary of this region element in the spatial element of the measurement region corresponding to the raw material surface. This count is performed using, for example, a memory array or a multichannel digital counter capable of performing digital processing system control. Each channel or memory location is associated with an area element of the raw material. When the estimated origin coordinate of each radiation corresponds to a specific area element, under the condition that the radiation angle is within the allowable range and the radiation energy is within the allowable range, the count value of the corresponding memory location or digital channel is increased. After recording a sufficient number of emissions, the count value of the raw material surface area element represents the respective radiation nuclide concentration.

The position measuring chamber of the detector of the device is contained in a gastight container which insulates and shields. On one side thereof the detector vessel has an ultra-thin outer wall, or window, which is in close proximity to or abuts the raw material located outside of the vessel. The function of this window is to insulate the detector from external conditions so that radiation is traversed from the raw material to the detector with minimal absorption and scattering. This window shall consist of a material having a low density and low atomic number while containing an electrically conductive layer.

The position measuring chamber in the detector consists of two or more relatively thin regions filled with a gas mixture and bounded by electrodes parallel to the surface of the raw material emitting the charged particles. If the raw material surface is planar, the electrode is also planar. The electrodes disposed between the regions consist of wires or conductive fibers arranged as parallel grids, cross grids, or meshes. These electrodes define the equipotential surface of the electrostatic field, but under the influence of the electrostatic field, electrons move from one area to another. The electrons move in the normal direction of the electrode surface. The external electrodes of the positioning chamber are made in the same way, but may also be made of film, flakes, laminate or solid material. They limit the equipotential surface of the electrostatic field, but do not need to allow electrons to be transferred. The electrode element is formed by printing, vapor deposition, plate, corrosion, or mechanization of the outer electrode surface.

The positioning chamber in the detector includes at least one detection area. As the position measuring chamber, a conventional multi-wire proportional chamber comprising two detection regions separated by a multi-wire proportional grid and partitioned by external electrodes can be used. The role of the detection zone is to measure the center of position of the small ionization group deposited along the segments of the radiation path. This measurement is performed by electroprocessing the charged particles from the conductive element of the electrode partitioned into the detection zones. This process calculates the position center of the signal on each electrode element, either directly or through an intermediate step. Their quantitation is proportional to the charge center coordinates of the ionization group parallel to the electrode surface. Three-dimensional measurements of these measurements are provided by the central surface location of the area or by the area where ionization is collected.

One electrode partitioning the detection area of the position measuring room in the apparatus is a multi-wire proportional grid. The other electrode in the position measurement chamber is in a more negative potential so that electrons are attracted towards this grid. In a multi-wire proportional grid, amplification of ionized electrons occurs in a strong electric field adjacent to a thin wire or a conductive fiber. Charge signals are observed in devices of multi-wire proportional grids. At least one other electrode adjacent to the multi-wire proportional grid is a parallel grid oriented at an angle with the conductive element of this multi-wire proportional grid or another electrode adjacent to the multi-wire proportional grid. Charge signals induced due to their capacitive coupling are observed on the elements of the adjacent grid. The signals on the elements of the two grid or grid-shaped electrodes partitioning the detection area are processed by the readout circuit so that the position center of the primary ionization group is measured in two dimensions.

In order to maximize spatial resolution, the device is designed to measure the first position as near as possible to the radiation origin along the radiation path. Position measuring room for measuring the first position is composed of a plurality of areas and may include up to five areas in the order of deposition area, amplification area, transmission area and two detection areas.

In the amplification region of the position measuring chamber, there is a sufficiently strong electrostatic field that causes the electrons to collide strongly with the gas atoms as they move through them, so that further electron generation stops from the gas molecules. This is the same amplification that occurs in a multiwire proportional grid. However, in this amplification region, a different method is not employed only in the vicinity of the electrode surface, but is employed in the entire gas volume. Depending on the gas mixture and the positioning chamber configuration, stable amplification coefficients of up to approximately 10,000 can be obtained for the primary ionized electrons completely crossing the amplification region. Amplification for the primary electrons varies exponentially with the thickness of the amplification region it traverses.

The main function of the amplification zone is to separate the ionization initiated on one side of the amplification zone from the ionization in the other zones in the position measurement chamber. Charges coming from the negative potential side are sufficiently amplified, but charges coming slightly outside this area are not amplified sufficiently. The detection region on the positive potential side of the amplification region almost completely copes with the amplified ionized electrons. On the negative potential side of the amplification region, a deposition region is added to limit the gas thickness, and the position measuring chamber having the amplification region within this gas thickness copes with the first ionization.

The primary function of the deposition zone is to construct a small, controlled thickness gas layer to deposit a primary ionization within the gas layer to measure a location in the path. This region is thick enough to contain an average of primary ionized electrons of hydrogen along the pathway. By providing controlled ionization samples and dissolving the detector window electrostatically, the deposition zone stabilizes the signal amplification and spatial resolution of the detector. The useful minimum thickness of the deposition zone is determined by the ionization capacitance of the detector gas. It is about 1mm for 0.3MeV beta emission and atmospheric gas. Thicker ones are undesirable, because they reduce the spatial resolution. Ionization from the deposition region through the grease or mesh electrode to the amplification region is swept by the intermediate electric field.

The transmission area is any gap in which the thickness between the amplification area and the nearest detection area is variable. The intermediate electrostatic field compared to that in the deposition zone sweeps ionization through the transmission zone into the detection zone. The transmission region electrostatically isolates the avalanche region from the detection region and functions as a preventer of mammalian secondary amplification. By controlling the ratio of the transmission area electrostatic field to the amplification area electrostatic charge, only the ionization fraction from the amplification area enters the transmission area. The flow of cations from the detection zone moving toward the amplification zone is controlled by the ratio of the transmission zone electrostatic field to the detection zone electrostatic field.

The second position measuring chamber of the detector may be a conventional multi-wire proportional chamber having two detection areas separated by a multi-wire proportional grid. It may also include additional electrodes and regions similar to the first measurement chamber. The function of the second measurement chamber of the detector is to measure the coordinates of the second position on the radiation path. With this information, the device can calculate the projection angle of the path with respect to the normal of the detector surface to one or both of the two dimensions parallel to the detector surface. The coordinates obtained from the first measurement chamber are adjusted by a simple equation that projects the estimated linear path on the surface of the raw material to estimate the coordinates of the radiation origin. This calculation can be easily performed at a high speed that is sufficient for practical application by analog or digital electronic circuits. Additional measuring chambers can be added to the detector to detect many locations along the path. In most cases, however, they do not sufficiently improve the spatial resolution and only add complexity.

The spatial resolution of the detector described above is strongly influenced by radiation scattering in the detector. As the charged particles pass through the chamber gas and the electrode material, this path is deflected in a general manner according to known physical principles. This scattering can be caused by significant errors in the estimation of the radial coordinates and angles.

The scattering effect on the spatial resolution increases rapidly when the radiation angle with the normal on the raw material surface is large and the radiation energy is small. The charged particle radiation energy from radionuclides is distributed in an easily understandable manner over a range from zero to maximum energy. This distribution causes some of the radiation from all radionuclides to have low energy. These factors provide the advantage of eliminating radiation at large radiation angles and small radiation energies, ie omitting the coefficients.

Path angle information provided by the methods and apparatus of the present invention may be used to eliminate radiation at wide angles. As the allowable angle range is limited, the spatial resolution can be improved at a low price. The operation of the detector can be predicted using the laws of physics and it is also possible to optimize the angle tolerance criteria for specific applications.

Since the primary ionization amount in the radiation path does not change much in most of the radiation energy areas actually used, the signal amplitude from the detector cannot be used as energy information. However, the detector can also be used for the radiation energy distribution of specific radionuclides by using plates made of absorbers. The absorbent material should be one having a low atomic number so as not to emit X-ray type light for energy. In addition, the absorber may be composed of different material layers to further reduce the generation of fluorescence. Charged particles released below a certain threshold energy cannot pass through the absorber and are therefore not detected in the measurement chamber located after the absorbent plate.

In the case of using an absorbent material, considerable scattering occurs in the absorbent material through which radioactivity passes. For this reason, it is necessary to measure a 2nd point on the path | route which is closer to the front of an absorbent material. As the measuring method, (1) a method of measuring the coordinates of the front of the absorbent material and introducing it into a third measuring chamber located behind the absorbent material and simply recording the presence or absence of the radiation path on the absorbent material, or (2) the deposition area immediately after the absorber plate. It is possible to use a method of molding a second measuring chamber having the same shape as the first measuring chamber having.

Another energy sorting method is a method of installing a flash plate having a composition and thickness capable of completely absorbing the radiation in all energy ranges generated by the source radiation nuclide at the next location of the second position measuring chamber. This scintillation plate can be replaced by a light changer that provides an electrical signal with an amplitude proportional to the amount of incident light. The energy of the emission can be measured from the amplitude of the photoconverter signal. Thus, emissions with energy below the threshold energy are blocked.

At low radionuclide concentrations, storm and other natural radiation are important backgrounds for the measured radionuclide distribution. Some of these background thoughts, for example background thoughts caused by the cosmic rays muon, generate a detector response and an indistinguishable detector response of the energy beta radiator. In some cases, it is desirable to suppress such a background.

The background coefficient may be any absorbing plate followed by one or more additional multi-wire proportional counters or scintillation counters thick enough that radiation from the source material does not penetrate them (1) from the main part of the detector to the opposite side of the source material, or (2 ) Can be suppressed by being installed on the same side as the main part of the detector or (3) at the drug position. These counters do not need to measure position, but only need to provide a signal when transmitted by radioactive radiation. Recording data from the position measurement output is suppressed during the instant time after this signal.

The detector configured as described above should be connected to a simultaneous control circuit, where (1) a suitable magnet signal is observed at the positioning electrodes of the first and second chambers for a short time, typically less than 1 microsecond, and (2) such a configuration. Is employed, a sufficient signal from the energy conversion counter is observed within such time period, and (3) in the case of including these, the signal from the protection counter is not observed within such time. Measurements should be made when events occur. Such simultaneous control circuits are known in the art. This circuit shall include a tolerance for their response time if the type, mechanical structure or operating conditions of the detector's individual measuring room and counter are different.

In addition, the detector configured as described above should be connected to a readout circuit to convert the underline signal from the electrode into a signal proportional to the coordinates and send it to the signal processing circuit, and convert the coordinate signal obtained from the readout circuit to the estimated coordinate of the radiation origin. do. In one of these circuits, a signal is obtained by multiplying signals from a plurality of conductive elements of an electrode partitioning the detection area by a weight proportional to the position of the element located in the electrode plane and along a coordinate perpendicular to the orientation of the electrode element. . The circuit also adds the basis weight signal and the unbalanced signal and divides the basis weight signal by the unbalanced signal. Thus, this quotient becomes the position center coordinate of the ionization group detected in the plane located in the boundary detection area and parallel to the boundary electrode and lying in the coordinate direction perpendicular to the arrangement direction of the conductive element of the electrode.

If the material surface is curved, correction factors should be used. This signal processing circuit is necessary for each coordinate of the surface of the raw material in order to perform the direction measurement. By estimating the two position measurements obtained from the coordinates along the radial path, the estimated radiation origin of the coordinates can be found.

1, 2 and 3 show three structures in cross section for planar detection electrodes in an apparatus designed to measure the distribution of radionuclides emitting charged particles at the surface portion of the planar raw material. . Each structure includes a first position measurement chamber consisting of five zones, which measure the first position on the path of charged particle radiation and the second position measurement chamber in the additional position measurement chamber. This detector has advantages as strong beta radiation, such as strontium-90 with a maximum radiant energy of 0.54 MeV or phosphorous-32 with a maximum radiant energy of 1.72MeV. The electrode plane of the detector is arranged in parallel with the plane of the raw material and has a size large enough to be comparable. At least 30 × 50 cm or more are practical.

In FIG. 1, the planar raw material 1 having a distribution of radionuclides radiating charged particles is arranged in close proximity to the outer hermetic window 2 and serves as an external electrode of the deposition region 3. The hermetic window 2 is thin, strong and densely stretched as having a low atomic number of conductivity that gas or water vapor cannot penetrate. The hermetic window consists of a coating material such as 50 micron polyester with 5 micron aluminum fused to the outside and colloidal graphite coated inside. The interior of the detector from the deposition zone 3 to the detection zone 16 is full of gaseous mixture and is designed to provide low electron adhesion and maintain parallel plate enlargement. The gas mixture is argon with 3-5% acetone or propane. For stable operation, high gas purity must be maintained and negative electrode solvents such as oxygen, water vapor and chlorinated hydrocarbons are required. Usually less than $ 1 million. The design estimate should describe the operation of the detector at atmospheric pressure. Because at very high or low energies of charged particles, the spatial resolution of the detector has to be improved by operation in higher or lower pressure, multiple hermetic designs.

The planar electrodes 21, 22, 25, 26, and 27 with the closed window 2 inside the detector are limited to five-zone measuring chambers for measuring point coordinates on the charged particle radiation path close to the plane of the raw material 1. do. The multiple wire proportional grid electrode 26 has the highest positive potential and the other electrodes have a continuous negative potential. Sedimentation zone 3 has a primary negative ionization population along the average radiation path and the other electrodes have a continuous negative potential. The deposition zone 3 is about 1 mm thick enough to provide a primary ionization population along the average radiation path. The electrostatic field in the deposition area is preferably about 50-100V / mm / atm.

The electrodes 21, 22 which divide the amplification region 4 must be very dense in order to minimize the deviation caused by mutual force of about 500-800 V / mm / atm in the strong electric field of the amplification region. The thickness of the amplification zone 4 should be about 3-8 mm and should be a thin zone to provide more accurate spatial measurement, but is an area portion that requires control over the homogeneity of the size. The electrodes 21 and 22 should be densely arranged with wires or fibers to minimize the electrostatic field irregularity and spatial quantization of the detector response at a pitch that is not more than 10 times the amplification area thickness. The diameter of the wire or fiber should be large enough not to act as a corona raw material, and the surface of the electrode should be flat for the same reason. Stainless steel or beryllium copper wire having a diameter of 50-100 microns is used for the electrode. However, in order to minimize scattering of charged particle radiation, it is advantageous to use materials having low density and atomic number, such as polyamide fibers with conductive coating.

Electrodes 25 and 27 are cathodes for electrode 26, which is a multi-wire proportional grid anode. The anode grid consists of tungsten or stainless steel with a diameter of 20-30 microns at a pitch of 1.5-2.5 mm, and the cathode consists of a 50-150 micron wire with a diameter of 1-3 mm. The distance between the anode and cathode should be about 4-8 mm. Narrow spacing improves forward spatial resolution but requires much control over uniformity of size. The coming signal amplitude will actually be reduced at the desired pole front pitch. Therefore, in order to minimize scattering of charged particle radiation, it is preferable to use a negative electrode material having a low density and low atomic number. Depending on the diameter and pitch of the anode wire, an electrostatic field of about 300-500 V / mm / atm would be required for the detection zone.

The transmission area 5 is located between the amplification area 4 and the detection area 7, and the electrostatic field and thickness of the transmission area change according to the design purpose. Thickness in the remnant zone increases isolation between the amplification zone and the transmission zone and improves stability in operation. Incidental side diffusion of electrons in the transmission region reduces the spatial quantization of the detector response. However, due to the extra thickness of the transmission area, measurement errors from scattering increase. The lower electrostatic field reduces the friction of electrons transmitted along the electrode 22, increases the isolation between the amplifying and transmission regions or reduces the amplitude of the signal and worsens the inherent accuracy of the position measurement. The thickness of the transmission area is about 3-15mm and the field strength is about 20-200V / mm / atm.

The structure of the detector shown in FIG. 1 has a second position measuring chamber consisting of detection areas 11 and 12 and is defined by cathode electrodes 31 and 33 and multi-wire proportional grid anode 32. The structure and operating characteristics are similar to those of the detection areas 7 and 8. The absorber material 9 and the detection zones 15 and 16 are optional. If included, the detection regions 15, 16 and the electrodes 35, 36, 37 have the same structure and operation characteristics as the detection regions 11, 12 and the electrodes 31, 32, 33. It is possible to combine the electrodes 27 and 31 as single electrodes. Such things are necessary to obtain the position information from the electrodes 25, 26, 32, 33.

The detector shown in FIG. 1 has at least two positioning multiple wire proportional real elements, i.e. electrodes 25, 26, 27, 31, 32, 33. When electrons reach the vicinity of the wire or fiber of the multi-wire proportional grid anodes 26 and 32 by ionization, local amplification occurs near the surface of the wire in the operating state. Negative charge arcs appear on the active anode wires and induced positive charges appear on the adjacent electrode elements. The divided electrodes are used for position measurement, and the electrodes for the linear coordinates are parallel and uniformly arranged with the wire arrays, and are connected with the wire groups or other conductive strips. Other geometries can be used for curved or nonlinear coordinates. The induced signal rapidly decreases in amplitude at the distance from the anode amplification position.

In some designs, signals can be processed to establish the center of the ionization group and obtain the center of charge location from the wires or other electrode elements of the electronic readout circuits. The detector shown in FIG. 1 is used in a simple but accurate manner. In other words, the branch, concentration constant, and electromagnetic delay line of the detector tab are directly connected to the wire of the grid electrode or a similar group of wires. The time difference between the peak signal at the maximum of the delay line is proportional to the position of the charge center. Another method is an analog or digital center circuit where the position of the signal from the electrode elements is divided by the weighted non-weighted sum. Each coordinate measured requires its own electrode elements and a readout circuit.

The detector shown in FIG. 1 is an optional element consisting of a multi-wire proportional chamber consisting of an absorber 9 and electrodes 35, 36 and 37, which are included when the detector has a limiting radiant energy for counting. . The material and thickness of the absorber should be chosen so that it almost stops all charged particle radiation at the specific energy. It is advantageous to use a low atomic number material such as carbon as the absorber in order to avoid generating energetic X-ray fluorescence which may be detected in any part of the device. It is not necessary to provide a position reading circuit for any of the electrodes. The appearance of the signal on the multi-wire proportional grid 36 indicates that the charged particle radiation has a permeable absorber 9.

The detector shown in FIG. 2 represents an optional structure including optional elements for the detector shown in FIG. This detector also has a first measuring chamber consisting of areas 3, 4, 5, 7, 8, which are limited by the window electrode 2 and the other electrodes 21, 22, 25, 26 and 27. It has the same structure and properties as the components of the same number in FIG. The absorber 50 is also used for the same purpose as the absorber 9 in FIG. However, the absorber 50 is conductive to the conductive material, becomes a thin film layer, and also acts as one electrode of the deposition region 41.

The detector in FIG. 2 has a position measuring chamber of the second five regions: the deposition region 41, the amplification region 42, the transmission region 43, the detection regions 45 and 46, the absorber electrode 50 and the electrode. Fields 51, 52, 55, 56, and 57. In addition to the absorber electrode 50 replacing the window electrode 2, each of the actual field regions 3, 4, 5, 7, 8, and the electrodes 21, 22, 25, 26, 27 are configured. It has the same structure and operation characteristics. The second detector in the structure responds only to the reflections passing through the absorber. Such radiation causes the detector to measure the ionization position close to the point exposed from the absorber and provide a second point on the radiation path. The detector shown in FIG. 2 includes additional selectors for suppressing natural radiation and includes both coupling transducers 62a and 64a and scintillators 62 and 64. The plate is separated from the other elements of FIG. 2 by any thick absorbers 61, 63. Signal recording from the other elements of FIG. 2 is suppressed when the signal is damped by one or both of the scintillators.

The detector of FIG. 3 represents an optional structure that includes any element for the detector shown in FIG. This detector also has a first chamber consisting of regions 3, 4, 5, 7, 8, which is limited by the window electrode 2 and the other electrodes 21, 22, 25, 26, 27. It has the same structure and properties as the components of the same number in FIG. The detector has a second position measuring chamber composed of detection areas 11 and 12, and is limited by electrodes 31, 32 and 33 and has the same structure and characteristics as the components of the same number in FIG. The scintillator plate 77 is thick enough to fully absorb some raw radionuclide radiation, and the signal measures the radiant energy from the photoconverter 78. As the signal, it can be used to stop the emission of radiation energy outside the acceptance range.

In the detectors of FIGS. 1 and 3, the surface inside the detector on the two points of the measured radiation path is almost at the center of the deposition region 3 and on the plane of the multi-wire proportional grid electrode 32. In the detector of FIG. 2, the measured two-point surface is almost at the center of the deposition zones 3 and 41. However, the effective thickness of the deposition region extends in the adjacent amplification region and is divided by the natural logarithm of the amplification gain factor for the basic electrons that completely pass through the amplification region at the same distance from the amplification region thickness.

4 is a diagram measuring a method of implementation as a planner detector constructed in accordance with the present invention. 4 is a cross-sectional view in which the raw material occupies points measured along the path in plane 10 and planes 13, 14. The radiation occurs at point 1, coordinate U, and is scattered in the detector along the path 20. The path of radiation is measured at points 17 and 6 on planes 13 and 14, ie at coordinates a and b. The linear path 23 is estimated from two coordinates a and b and intersects the raw material plane at coordinate V. The measuring planes 13 and 14 exist at distances C and D along the normal from the raw material plane 10. The following formula is used to adjust the measurement by estimating point 17 and coordinate V.

The assessment should be calculated for the two coordinates of the raw material surface as individual emissions are recorded. The evaluation may be calculated by circuits included in the grant signal processing device or the digital data processing device. As shown in FIG. 4, there is an error (V-U) related to the intrinsic error for the evaluation or position measurement due to scattering in the detector. If the specific detector can understand the specific material, the geometry and the material principle well, the evaluation distribution of the error due to scattering can be known in advance. This error is rapidly increased by wide-angle radiation to normals and radiation in low-radiation energies.

The spatial resolution at good sensitivity can be improved by excluding wide angle radiation, low energy radiation or both. Each absorbent body 9, 50 shown in Figs. 1 and 2 is introduced to filter the radiation so that it is counted only above the limit energy. The signal amplitude at photoconverter 78 of FIG. 3 can also be used to generate similar energy limits. The difference in the measured coordinate values (b-a) shown in FIG. 4 is proportional to the tangent of the projection path angle with respect to the normal. When the raw material surface shows a curve, the difference in coordinate values is multiplied by an appropriate correction factor according to the special geometry of the curved surface. This value can be compared to the extreme value to rule out wide-angle radiation.

5 shows a block diagram of an electronic circuit that implements coordinate estimation and path angle limitations implemented in accordance with the method of the present invention. This circuit performs a procedure for one coordinate. The digital position measurement required as an input in the circuit is calculated by both reading circuits shown in Figs. 5B or 5C.

FIG. 5B shows a readout circuit for one coordinate from one position measuring room on a branch concentrated constant delay line. The isolation conductive elements of the planar electrode are connected directly to the input line 301 at the delay line 302, and an end of the delay line is connected to the timing circuit 305. The output 306 of the timing circuit 305 is a positioning signal.

5c shows a readout circuit for one coordinate from one position measuring room based on the center of gravity calculation. The separate conductive elements of the planar electrode are connected to an amplifier 311 as an input 310, the amplifier output being transferred directly to a summer 312, yielding a non-weighted sum as an output, and another summer 314. The weighted sum is calculated as the output along the weighted network 313, and the individual signals are proportionally weighted with respect to the calculated position of the conductive element. The calculator 315 obtains the quotient of the weighted sum divided by the unweighted sum. Output 317 provides a signal proportional to the location center. As shown in FIG. 4, position measurements (a, b) are required on inputs 94 and 95 corresponding to measurements a and b. As shown in FIG. 4, input 96 provides a constant proportional to the distance of C / (D-C). This constant value is held in register 108.

In FIG. 5 the subtractor 110 adopts a and b as inputs and calculates the difference of inputs b-a as outputs. The multiplier 11 takes as input the difference b-a and the proportionality constant C / (D-C) and calculates their product as an output. Subtractor 112 takes this product and measurement a as input and calculates the difference, V = a- (b-a) C / (D-C), as output 115.

The output is proportional to the estimated radiation origin coordinate V as shown in FIG.

The output difference b-a of the subtractor 110 in FIG. 5 is used as one input in the comparator 117. Another comparator input is carried in the register 109, which retains the value from the input 97 corresponding to the value of (b-a) when the radial path is present at an angle that is too large for the adopted normal. The comparator 117 generates a signal as an output when the difference b-a of the input is equal to or less than the limit value. The above are intended for signal adoption of the combined projection angle.

The circuit of FIG. 5 may be performed using a digital integrated circuit that has programmable operation for a static clock. Performances such as measurements of a and b, constants C / (D-C) and angular limit values can be digitized or displayed as coded representations. It is also possible to perform the same analog circuit. In analog implementation, the input must be represented as an analog voltage or current.

6 shows the structure of a complete detector including an enclosure, a readout circuit and a rejection counter. The raw material 1 is placed on the window 2 of the main waste waste 130. Inside this there is a measurement chamber as in the structure of FIG. 2, where the five-zone measurement chamber 10 carries an absorber 15 and a second five-zone measurement chamber 19. The signal cables 121 and 122 carry signals from the position measuring electrodes of the measurement chamber, which are located on the rear wall side of the detector of the electronic readout circuits 125 and 126 located inside the rear sealed container 128.

Inside the main airtight container 130 of FIG. 6, there is an optional thick absorber 61 and a multi-wire proportional chamber 62, with a position measuring chamber. The electrodes 35, 36, 37 are shown in FIG. 1. Is done by)). The optional absorbent 61 is thick enough to stop radiation from the raw material, and the measurement chamber responds only to spacecraft or natural radiation. Opposite to the raw material 1 from the detector, there is a selective separation hermetic container 70 thick absorber 71 and a multi-wire proportional chamber 72, which are configured in the same manner as the multi-wire proportional chamber 62. . Each thread responds only to natural radiation. The function of the two optional counters is to provide reject signals for spacecraft and other natural radiation. The signals in the position measuring chamber of the detector where the reject signal occurs in a short time can be ignored. Rejection counters allow the weak material distribution to be recorded from the maximum radioactive radiation at the natural origin without natural radiation.

7 shows the main elements of a data collection device incorporating the device and method of the present invention. A detector 81, as shown in FIG. 1, 2, or 3 and 6, is connected to a high voltage generator 84 and a gas supply 85 which defines an operating state. The readout circuit 87 processes a charge signal that generates a signal for the ionization coordinates measured at the position measurement room factor. The position measurement is an input to the signal processing circuit 88 for the individual coordinates of the estimated radiation point on the surface of the raw material as in FIG. The coordinate outputs of the signal processing circuit 88, the signals from the other detection elements and the angle comparison output of the signal processing circuit 88 are inputs to the coincidence and control circuit 89, which are bounded by both coupling path angles. The data processor 90 is operated to read the estimated radiative origin coordinates in the signal processing circuit 88 when present therein.

The data collection processor 90 is arranged to control the operation of the chamber by reading signals from the position measurement chamber or by adjusting the electrode voltage. Also, a predetermined signal level, a predetermined time interval, an extreme value associated with wide-angle radiation, and a predetermined emission energy range are set in the signal processing circuit 88.

The data processor 90 accumulates counts adopted in the data collection memory 91 and takes the form of a multi-channel counter 91A or other protocol storage device. The data processor 90 also records and analyzes the estimated origin coordinate emission from the raw material surface, and the results of the analysis appear on the display 92. The display is present as a mapping or image of the coordinates of the data processor 90.

Claims (40)

Apparatus for measuring the two-dimensional distribution of radionuclides radiating charged particles at the surface of the planar raw material, comprising: (a) a composite having a thickness that minimizes their absorption and scattering as they pass through the charged particles; A gas tight vessel formed with a thin wall or window disposed adjacent to the raw material; (b) an ionization generated by the radiation charged particles passing through the first plane at two coordinates of the first plane, the first plane being arranged in proximity to the plane of the raw material; A first position measuring chamber oriented to measure a first position of a signal and installed inside the closed container; (c) displace from the hermetic window and arrange a second plane parallel to the raw material, wherein the ionization signal generated by the radiated charged particles passing through the second plane at two coordinates in the second plane A second position measuring room which is oriented to make a two position measurement and is installed inside the closed container; (d) immediately before passing through the measuring positions intersects the plane of the raw material material so as to compare the measuring positions of the ionization signals occurring during a predetermined time in the first and second position measuring chambers and to confirm the estimated radiation origin; Calculating a coordinates of the point to be measured, and further comprising circuit means for determining whether the difference in the measurement positions exceeds limit values associated with an estimated path of the maximum projection angle with respect to the first and second planes. Device. The measuring apparatus according to claim 1, wherein the specifications of the first and second position measuring chambers match the surface specifications of the raw material. 10. The planar electrodes of claim 1, wherein each position measurement chamber is a multiple wire proportional detector, wherein the multiple wire proportional chamber consists of two detection zones, each detection zone having planar electrodes oriented parallel to the surface of the raw material. The electrodes partitioning each other by the gas volume, the electrodes partitioning the detection zones, consist of a thin wire or a grid of conductive fibers, in which the strong electrostatic field provided by the planar electrodes is primary ionized. By moving the electrons toward a thin wire or fiber grid, generating secondary propagation of electrons in the wire or fiber division, position dependent charge signals are provided at one or two of the planar electrodes that partition the detection regions. The readout circuit from the thin wire or fiber grid plane Measuring device, characterized in that in one or both coordinates to determine the location the center of the ionization. The gas chamber of claim 1, wherein the first position measuring chamber comprises a plurality of gas volume regions that are partitioned from each other by planar electrodes oriented parallel to the source material and utilizing ionization proportional amplification in the gas. The electrodes, each partitioning two of the volumetric regions, are configured in a mesh or grid so that electrons from one region can be transferred to the other region, and the plurality of gas volumetric regions are in the following order from the raw material: (I) deposit primary ionization electrons from a cross section of a charged particle emission track disposed closest to the source material and proximate to the surface of the source material, within which the area is defined. A strong electric field provided by the planar electrodes moves the primary electrons away from the source material Sedimentation zones; (b) a strong positive field disposed after the deposition region, which propagates the primary electrons deposited in the deposition region, provided by the planar electrodes partitioning this region away from the source material. An amplification region that moves to the surface and induces secondary proliferation of electrons over the volume of gas in this region at a constant amplification rate per unit thickness traversed by the electrons in this region; (c) a strong electrostatic field disposed after the amplification region, insulated the amplification region from the region following this region, provided by planar electrodes partitioning this region away from the source material. A transmission area to move so that; (d) ionization is detected and measured with a planar electrode disposed after the transmission region and consisting of a thin wire or a grid of conductive fibers that partitions these regions, within the regions by the planar electrodes partitioning these regions Position-dependent charge signals at one or two of the planar electrodes partitioning these regions by moving the provided strong electrostatic electrons toward the thin wire fiber grid, thereby generating secondary propagation of electrons near the wire or fiber. And two detection zones from which the reading circuit measures the center of position of ionization in one or two coordinates of the thin wire or fiber grid plane. The method of claim 1, wherein the second position measuring chamber is composed of two detection regions partitioned from each other by planar electrodes oriented parallel to the surface of the raw material, wherein the electrodes partitioning the detection regions are thin wire or conductive. It consists of a grid of fibers, in which the strong electrostatic field provided by the planar electrodes moves the primary ionization electrons toward a thin wire or fiber grid, so that secondary propagation of electrons near the wire or fibers Is generated so that position dependent charge signals are provided at one or two of the planar electrodes defining these detection regions, from which the readout circuit is ionized at one or two coordinates of the thin wire or fiber grid plane. Measuring device, characterized in that to measure the position center of the. The method of claim 5, wherein the second position measuring chamber is disposed after the absorbing plate and the third ionization sensing chamber, the composition and thickness of the absorbing plate absorbs the radiation-charged particles having a radiation energy below a predetermined threshold, Some of the radiation-charged particles with radiation energy above a threshold are selected for delivery, and the third ionization sensing chamber also consists of two detection zones that are partitioned from each other by planar electrodes oriented parallel to the surface of the raw material. The electrode partitioning these detection regions consists of a thin wire or grid of conductive fibers, in which a strong electrostatic field provided by the planar electrodes moves the primary ionization electrons toward the thin wire or fiber grid, This detection zero is generated by generating a secondary multiplication of electrons near the wire or fibers. To be provided to one of said planar electrode for partitioning or two electrode position dependent charge signal in, and the call venom origin from which the measuring device, characterized in that to determine the presence of the emission of charged particles passing through the absorption plate. 6. A solid scintillator plate according to claim 1 or 5, next to the second position measuring chamber, the composition and thickness of which are selected to absorb radiation charged particles of any energy generated by the source radionuclide are arranged. The plate generates an optical signal due to radioactive ionization, which is converted into an electrical signal by a photoconverter, and the readout circuit is configured to allow only the charged particles having energy within a predetermined range to be read by an amplitude of the electrical signal. Measuring device, characterized in that for determining the energy of the charged particles absorbed by the scintillation plate from. The absorbing plate according to claim 1, 3 or 4, wherein an absorbing plate is disposed immediately before the second position measuring chamber, wherein the composition and thickness of the absorbing plate absorb radiation-charged particles having radiation energy below a predetermined threshold. And planar electrodes, selected to deliver some radiated charged particles having radiation above the threshold, and wherein the second position measuring chamber utilizes dimerization proportional amplification in the gas and is oriented parallel to the raw material. A plurality of gas volume regions partitioned from each other by means of which the electrodes respectively partitioning two of the gas volume regions are configured in a mesh or grid so that electrons from one region can be transferred to another region, In addition, the plurality of gas welding regions are arranged in the following order from the raw material, that is, (a) the raw material The primary electrostatic field, which is disposed closest to and deposited primary ionizing electrons from a cross section of the charged particle emission track proximate to the surface of the raw material, is defined by planar electrodes that define this region. A deposition region for moving electrons away from the raw material; (b) a strong electrostatic field disposed after the deposition region and propagating the primary electrons deposited in the deposition region in which the planar electrodes partitioning this region escape electrons from the source material. An amplification region that moves to the surface, and also induces secondary proliferation of electrons over the gas volume in this region at a constant amplification rate per unit thickness traversed by the electrons in this region; (c) a strong electrostatic field disposed after the amplification region, insulated the amplification region from the region following this region, provided by planar electrodes partitioning this region away from the source material. A transmission area to move so that; (d) ionization is detected and measured with a planar electrode disposed after the transmission region and consisting of a thin wire or a grid of conductive fibers that partitions these regions, within the regions by the planar electrodes partitioning these regions Position-dependent charge signals at one or two of the planar electrodes partitioning these regions by moving the provided strong electrostatic electrons toward the thin wire fiber grid, thereby generating secondary propagation of electrons near the wire or fiber. And two detection zones from which the reading circuit is arranged so as to measure the position center of the ionization in one or two coordinates of the thin wire or fiber grid plane. The device according to claim 1, 3, 4 or 5, which is connected directly to the conductive elements of the electrode partitioning the detection area for either or both dimensions of any of the position measuring chambers. It consists of a lumped constant electromagnetic delay line with tabs, which employs a readout circuit which obtains the center of charge position in one dimension, and detects in a plane arranged in the detection area parallel to the electrodes partitioning the detection area. And an electronic timing circuit means for measuring the time difference between the peak signals across the delay line obtained from the coordinate measurement with respect to the position center of the ionization group to be within the coordinates of the orientation and normal direction of the conductive elements. Measuring device. 7. A signal according to claim 1, 3, 4 or 6, with respect to either or both dimensions of any of the positioning chambers, from various conductive elements of the electrode partitioning the detection zone. Multiplied by weights proportional to the positions of the elements along coordinates that are in the plane of the electrode and in the orientation and normal direction of the elements of the electrode, sum the weighted signals and the non-weighted signals, respectively, and sum the weighted sums And a readout circuit means for dividing by the weighted sum, the output from the division being relative to the position center of the ionization group detected in the plane disposed in the detection area parallel to the electrodes partitioning the detection area. Measuring coordinates, said coordinates being the orientation and normal direction of said conductive elements. The method of claim 8, wherein for either or both dimensions of the second position measuring chamber consists of a concentrated integer electromagnetic delay line having tabs directly connected to the conductive elements of the electrode partitioning the detection area, thereby providing a charge location within one dimension. The readout circuit for obtaining the center and at the both ends of the delay line obtained from the measurement of the coordinates with respect to the position center of the ionization group detected in the plane disposed in the detection area so as to be parallel to the electrodes partitioning the detection area. And an electronic timing circuit means for measuring the time difference between the peak signals within the coordinates of the orientation and normal direction of the conductive elements. 9. The method of claim 8, wherein for either or both dimensions of the second position measuring chamber, signals from various conductive elements of the electrode defining the detection area are in the plane of the electrode and the orientation and normal of the elements of the electrode. A readout circuit means for multiplying weights proportional to the positions of the elements along a coordinate in a direction, summing the weighted signals and the non-weighted signals, respectively, and dividing the weighted sum by the non-weighted sum; The output from is the measurement coordinates for the center of position of the ionization group detected in the plane disposed in the detection area so as to be parallel to the electrodes partitioning the detection area, which is the orientation and normal direction of the conductive elements. Measuring device, characterized in that. A measuring method for determining the position of a radionuclide radiating charged particles in a plane or curved portion of a source material to be mapped, comprising: (a) a first ionization detection having a detection area parallel to and consistent with the surface area to be mapped; Using a device to measure the location center of ionization for a fragment of the radiation path proximate to the radiation origin, and (b) at least one ionization detector having a sensing area that is parallel to and conforms to the surface area being mapped. Further using to measure the position center of ionization for the fragment displaced from the radiation origin, and (c) estimating the charged particle radiation origin and direction using means for associating coordinates obtained from the ionization detection elements. Measuring method characterized in that consisting of. 14. The apparatus of claim 13, wherein the means for associating coordinates obtained from the ionization detection elements further comprises positional measurement differences obtained in the plane from the first and subsequent ionization detection elements with respect to one or both dimensions of a raw material surface. And (a) the smaller than the differences in the coordinates obtained from the first and subsequent ionization detection elements based on the position differences and the distance between the surface being mapped and the measurement surface of the detection elements. The coordinates obtained from the first ionization detection element are divided by the distance between the measurement surfaces of the first and subsequent detection elements, and the correction factor for other than planar surfaces on the distance between the measurement surface of the first detection element and the measurement surface. A straight line through the positions obtained from the position measurements, multiplied by a distance ratio that is a multiplied value The estimated radiation origin coordinate by observation and (b) the ratio of the coordinate difference to the distance between the measurement surfaces of the first and subsequent ionization detection elements, or a quantitative proportional thereto, depending on the allowable radiation angle range To adjust the coefficient of radiations, multiplied by a correction factor for surfaces other than planner surfaces, at least two of the tangents of the estimated projection radiation angle by linear observation through the positions obtained from the position measurements Measuring method characterized in that for determining the dimension in one. 14. The absorber of claim 13, wherein the absorber is of a composition and thickness that prevents the passage of radiated charged particles from the mapped surface when the radiant energy is below a predetermined limit, the absorber being substantially parallel to the area of the mapped surface. Radiation having a matching area, displaced from the surface to be mapped, disposed between two elements of the ionization detection accumulator, and ionized by the ionization detector on one side of the absorber remote from the surface to be mapped Measuring method, characterized in that it is used to limit the counting operation. 15. The method of claim 13, wherein an energy measurement ionization detection element of a composition and thickness is used which completely absorbs and quantifies the radiated charged particle energy of any energy generated by the source radionuclide on the surface. Having an area that is parallel and generally coincident with the area of the surface, which is more displaced from the surface to be mapped than any of the ionization detection elements described in claim 13, and permits counting operations for radiation in accordance with an acceptable range of radiation energy. Method of measurement characterized in that it is used to limit. 17. The method according to any one of claims 13 to 16, wherein a digital recall of the radionuclide distribution on the mapped surface is obtained by using a multichannel digital counter or memory array that is run under the control or under the control of the digital processing system. The multi-channel digital counter or memory array is characterized in that the radiant angles determined according to claim 14 are within the allowable range of radiant angles, and that the radiant energies limited by or determined by claim 15 are measured. If the range of allowable radiant energies and the estimated radiant origin coordinates are within the spatial partition of the area elements of the mapped surface, the mapped coefficients are incremented for each emission recorded by the ionization detector elements. The side being used to relate to each area element of the surface Way. 15. The method of claim 13, wherein a multi-wire gas proportional chamber is used for any of the ionization detection elements, wherein the multi-wire proportional chamber consists of two detection zones, each of which is parallel to the surface of the raw material. A gas volume partitioned from one another by oriented planar electrodes, the electrode partitioning the detection regions being comprised of a thin wire or a grid of conductive fibers, within the detection regions, provided by the planar electrodes An electric field is placed at one or two of the planar electrodes that partition the detection zones by moving the primary ionized electrons toward a thin wire or fiber grid, causing a secondary propagation of electrons near the wire or fibers. Allow dependent charge signals to be provided from which the readout circuitry The measurement method, characterized in that to measure the position of the center of the ionization at one or both coordinates of the fiber grid plane. 19. The method according to claim 18, wherein the multi-circuit wire proportional formula is provided by planar electrodes which are each oriented parallel to the raw material and partitioned by planar electrodes which are defined by curved or planar planar electrodes. An amplification that causes electrons to move away from the source material within this region while inducing secondary proliferation of electrons across the gas volume in this region at a constant amplification rate per unit thickness traversed by the electrons in this region. An electrode partitioning the amplification region away from the source material towards the multi-wire gas proportional chamber, and an electrode partitioning the amplification region from the source material towards the amplification region, from the amplification region. To transfer electrons into the multi-wire gas proportional chamber By configuring the electrode mesh or grid, the measuring method in which the amplified region from the amplification region characterized in that that used to multiply the primary electrons flowing toward the raw material. 20. The apparatus of claim 19, wherein the multi-wire gas proportional chamber and the amplification region are used together with a transmission region that insulates the multi-wire proportional chamber from the amplification region. A multi-line gas proportional chamber defined by the gas volume defined and partitioned, and within this transmission region an electrostatic field provided by the electrodes partitioning this transmission region and weaker than the electric field of the amplification region to transfer electrons to the amplification region. And moving from the to the multi-wire gas proportional chamber. 20. The method of claim 19, wherein the amplification region comprises a deposition region disposed on a side of the amplification region toward the source material for depositing primary ionized electrons from a fragment of the charged particle emission track proximate the surface of the source material; Used together, the deposition region consists of a gas volume defined and partitioned by an electrode on the side of the raw material side and a recent electrode that partitions the amplification region, and within the deposition region defines the deposition region. A weaker electrostatic field provided at the electrodes and rather than the development of the amplification region causes electrons to move from the source material toward the amplification region, and the recent electrode partitioning the amplification region consists of a meshed grid to To transfer electrons to the amplification region Positive way. The method of claim 1, wherein at least one multi-wire counter utilizing ionization proportional amplification in a gas is disposed adjacent to the raw material material away from the location measuring room, or adjacent to the second location measuring room away from the raw material. The one or more multi-wire counters have an orientation coincident with or covering the area of the raw material material and having an orientation parallel to the surface of the raw material material, the signal from the one or more multi-wire counters indicates background radiation generation, and Measuring device for inhibiting recording of signals from the first and second position measuring chambers during background radiation generation. 23. The apparatus of claim 22, wherein the multi-wire counter comprises an absorber plate of thickness and composition capable of stopping all charged particle emission from the source material, the absorber plate disposed on the source material side of the multi-wire counter. Measuring device, characterized in that. 14. The method of claim 13, further comprising one or more multiples disposed adjacent to the source material away from the ionization detection elements or adjacent to the last ionization detection device away from the source material and utilizing ionization proportional amplification in a gas. Utilizing a wire counter, the at least one multi-wire counter covers an area that is identical to or greater than the surface of the raw material material and also has an orientation parallel to the surface of the raw material material, wherein a signal from the at least one multi-wire counter generates background radiation. And recording of a signal from the ionization detection elements during the generation of background radioactivity. 25. The apparatus of claim 24, wherein the multi-wire counter also includes an absorber plate of a thickness and composition capable of stopping all charged particle emission from the source material, the absorber plate being on the source material side of the multi-wire counter. Measurement method characterized in that the arrangement. The flashlight counter of claim 1, wherein one or more flash counters are disposed adjacent to the raw material at a distance from the position measuring chamber or adjacent to the second position measuring chamber at a distance from the raw material, wherein the flash counter is driven by radiation to provide light. Consisting of a solid scintillation material for generating a signal, the optical signal being converted into an electrical signal to an optical transducer, and wherein the one or more scintillation counters cover an area that matches or exceeds the surface of the raw material, And having a parallel orientation, wherein the signal from the one or more flash counters indicates background radiation generation and inhibits recording of signals from the first and second position measuring chambers during the background radiation generation. 27. The apparatus of claim 26, wherein the flash counter comprises an absorbent plate of thickness and composition capable of stopping all charged particle radiation from the raw material, wherein the absorber plate is disposed on the raw material side of the flash counter. Characteristic measuring device. 15. The apparatus of claim 13, wherein one or more flash counters are utilized that are located adjacent to the source material at a distance from the ionization detection elements or adjacent to the last ionization detection device at a distance from the source material. Wherein the signals from the one or more flash counters indicate background radiation generation, and the ionization detection elements during the background radiation generation, having an orientation that coincides with or is parallel to the source material surface and is also parallel to the source material surface. Measuring the signal from the device. 29. The apparatus of claim 28, wherein the multi-wire counter also includes an absorber plate made of a thickness and composition capable of stopping all charged particle radiation from the source material, the absorber plate being on the source material side of the multi-wire counter. Measuring method, characterized in that the arrangement. The information of claim 1, wherein the information when the signals from the position measuring room rises above a predetermined level within a predetermined time, and when the measured positions exceed the limit values associated with the estimated radiation path of the maximum angle, is determined. And a controller for recording from the second position measuring chamber. 7. The method of claim 6, wherein when the signals from the position measurement chamber rise above a predetermined level within a predetermined time, when the measured positions exceed limit values associated with the estimated radiation path of the maximum angle and the third ionization detection. And a controller for causing information from the first and second position measuring chambers to be recorded when signals from the chambers exhibit radiation having energy within a predetermined range. 8. The method of claim 7, wherein the signals from the position measurement chamber rise above a predetermined level within a predetermined time, when the measured positions exceed limit values associated with the estimated radiation path of the maximum angle and from the photoconverter. And a controller for causing information when signals indicate radiation having energy within a predetermined range to be recorded from the first and second position measuring chambers. 15. The method of claim 13, wherein the information when the signals from the position measuring room rise above the predetermined level within a predetermined time, and when the measured positions exceed the limit values associated with the estimated radial path of the maximum angle, is determined by the first information. And a controller for recording from the second position measuring chamber. 16. The method of claim 15, wherein when the signals from the position measurement chamber rise above a predetermined level within a predetermined time, when the measured positions exceed limit values associated with the estimated radiation path of the maximum angle and the third ionization detection. And a controller for causing information from the first and second position measuring chambers to be recorded when signals from the chambers exhibit radiation with energy within a predetermined range. 17. The apparatus of claim 16, wherein the signals from the position measurement chamber rise above a predetermined level within a predetermined time, when the measured positions exceed limit values associated with the estimated radiation path of the maximum angle and from the photoconverter. And a controller for causing information when signals indicate radiation having energy within a predetermined range to be recorded from the first and second position measuring chambers. 31. The apparatus of claim 30, coupled to the position measuring chambers and the controller, the signal being estimated from the position measuring chambers and the electrode voltages of the position measuring chambers adjusted to estimate the predetermined signal level, the predetermined time, and the maximum projection angle. Providing data collection processor means for setting the limits associated with the radiation path to control the operation of the position measuring chambers and for constructing, recording, analyzing, or displaying a mapping or image of the radioactive radiation coordinates from the raw material surface. Characteristic measuring device. 32. The apparatus of claim 31, connected to the position measuring chambers and the controller, the signal being estimated from the position measuring chamber and the electrode voltage of the position measuring chambers being adjusted to estimate the predetermined signal level, the predetermined time, and the maximum projection angle. Controlling the operation of the position measuring chambers by setting the limit values and the predetermined radiant energy range associated with the radiation path, and constructing, recording, analyzing or displaying a mapping or image of the radioactive radiation coordinates from the raw material surface. And a data collection processor means. 33. The apparatus of claim 32, coupled to the position measuring chambers and the controller, the signal being estimated from the position measuring chamber and the electrode voltage of the position measuring chambers being adjusted to estimate the predetermined signal level and the predetermined time and maximum projection angle. Controlling the operation of the position measuring chambers by setting the limit values and the predetermined radiant energy range associated with the radiation path, and constructing, recording, analyzing or displaying a mapping or image of the radioactive radiation coordinates from the surface of the raw material. And a data collection processor means. 34. The system of claim 33, connected to the position measuring chambers and the controller, the signal being estimated from the position measuring chamber and the electrode voltage of the position measuring chambers being adjusted to estimate the predetermined signal level and the predetermined time and maximum projection angle. A data collection processor means for setting the limit values associated with the radiation path to control the operation of the position measuring chambers and for constructing, recording, analyzing or displaying a mapping or image of the radioactive radiation coordinates from the raw material surface; Measuring method characterized in that. 36. A system according to claim 34 or 35, connected to said position measuring chambers and said controller to read signals from said position measuring chambers and adjust electrode voltages of said position measuring chambers to adjust said predetermined signal level and said predetermined time and Control the operation of the position measuring chambers by setting the limit values and the predetermined energy radiation range associated with the estimated radiation path at the maximum projection angle, and construct, record, or map a mapping or image of the radioactive radiation coordinates from the surface of the raw material; Measuring data collection processor means for analyzing or displaying.

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