Method of determining spectral and spatial distribution of deceleration radiation photons and corresponding device. RU patent 2513641.
 Neutron sensor / 2503975In a neutron sensor comprising a source of charged particles generated under action of neutron radiation and an elastodeformed element installed in a body, the source of charged particles is made of a stable non-radioactive material, opposite to the source of charged particles there is an absorber of charged particles, and on the absorber of charged particles there is a reflecting prism installed, which is connected with an optical system of light beam input and output made in the form of an optic window in a body of the sensor, opposite to which there is a unit of a reflector from a semitransparent mirror and reflecting prisms. |
 Monodirected neutron radiation detector / 2495457Monodirected neutron radiation detector consists of a housing, a collector in form of a metal plate and a dielectric layer of a hydrogen-containing material, wherein the dielectric layer of hydrogen-containing material is enclosed in a current-conducting shell; the collector in form of a metal plate is enclosed in an insulating shell; between said shells there is an electrostatic screen; a connection line from the current-conducting shell enclosing the dielectric layer of hydrogen-containing material is connected to an inverting channel of a differential amplifier, and a connection line from the collector is connected to the non-inverting channel of the same amplifier. |
 Neutron logging tool having source and target with deuterium-tritium gas admixture / 2486546Neutron logging tool has a neutron generator including a mixture of deuterium gas and tritium gas selected to generate a desired output ratio of 2.45 MeV and 14 MeV neutrons, said ratio ranging from 10:1 to 2:1; at least two neutron detectors spaced from said neutron generator. |
 Method of calibrating neutron emission detectors / 2485549Method involves measuring on a working reactor sensitivity of detectors which will then be used as reference detectors, based on the sensitivity of which the sensitivity of the calibrated detectors is determined; the method being characterised by that for reference emission detectors, consisting of a collector and an emitter made from powdered hafnium dioxide (HfO2) enclosed in a casing, the weight of the emitter is measured by subtracting from the total weight of the casing and the emitter, the weight of the casing, which is determined using the formula: (H), where Rres is resistivity of the material of the emitter casing, (ohm·m); ρ is the density of the material of the emitter casing, (kg/m3); g is gravitational acceleration, (m/s2); L is the length of the emitter casing, (m); R is the electrical resistance of the emitter casing, (ohm); the relationship between sensitivity of reference detectors and the weight of their emitters is then determined, after which sensitivity of the calibrated emission detectors is determined using the formula: η=APemit+B, (A·c), where Pemit is the weight of the emitter material, (II); A -is a coefficient, (A·s/N); B is a coefficient, (A·C); wherein the weight of the emitters of the calibrated emission detectors is also defined as the weight of emitters of reference detectors, and the values of coefficients A and B are selected in the range from 8.8·102 to 10.6·102 and from 7.6 to 9.2, respectively. |
 Apparatus and method for measuring count rate / 2483328Apparatus for measuring count rate has a measuring unit (1), having a division chamber (CH); a neutron generator (6) which emits neutrons in form of periodic pulses towards the division chamber; a neutron counter (K) for detecting and counting neutrons emitted by the neutron generator (6); a computation circuit (34), wherein the signal generated by the division chamber and the count signal are processed in a predetermined time window during the neutron emission period to output a signal which is a signal generated by the division chamber and a signal which is a count signal, and based on the signal which is a signal generated by the division chamber and the signal which is a count signal, the count rate of the division chamber, which is standardised based on the count signal, is calculated. |
 High-strength neutron shield / 2473100Shield for equipment for geophysical exploration in wells (logging) has an external layer in which there is reinforcing fibre which lies in a matrix, and an internal layer which contains material capable of absorbing slow neutrons and is embedded into the matrix. The material which is capable of absorbing slow neutrons is selected such that it emits induced gamma radiation with energy outside the selected energy range. |
 Neutron sensor / 2470329Invention relates to the field of measurement equipment, namely, to metrology of neutron radiation in presence of background radiations and electromagnet noise. The substance of the invention consists in the fact that a neutron sensor comprises a source of charged particles occurring under action of neutron radiation and an elastic element, at the same time the source of charged particles is made of stable non-radioactive material, opposite to the source of charged particles there is an absorber of charged particles installed, on the source of charged particles and on the absorber of charged particles there are tabs of an optical diaphragm installed, and the optical diaphragm is connected to the optical system of light beam entrance and exit. |
 Fast neutron sensor / 2469356Fast neutron sensor has a source of charged particles arising under the action of neutron radiation and an elastic member, wherein the source of charged particles is made from stable, non-radioactive material. A charged particle absorber is placed opposite the source of charged particles, at least one of them being mounted on the elastic member in form of a winding of a cylindrical spring, or helical spring, or torsional spring, or shell-type spring. |
 Neutron detector / 2469355Neutron detector has a source of charged particles arising under the action of neutron radiation, wherein the source of charged particles is made from stable non-radioactive material. A charged particle absorber is placed opposite the source of charged particles. The source and/or absorber of charged particles are electrically connected to gates of field-effect transistors and the field-effect transistors are connected to a circuit for detecting change in transistor channel resistance. The field-effect transistors are connected in opposite arms of the bridge electrical circuit. |
 Neutron detector / 2469354Neutron detector has a source of charged particles arising under the action of neutron radiation, wherein the detecting element of the sensor is in form of a multilayer structure consisting of alternating layers of a source and an absorber of charged particles. The layers of the source of charged particles are made from stable non-radioactive material and the layers of the source and/or absorber of charged particles are electrically connected to gates of field-effect transistors, and the field-effect transistors are connected to a circuit for detecting change in transistor channel resistance. |
 Electric magnet for spectrometry of neutron decomposition / 2256197Device realizes electric magnet for spectroscopy of decomposition of neutron, with current configuration, providing magnetic field of 1/R type, where R - radial distance from device axis. Magnet includes no iron and field is fully absent at distance of near 25 cm and more from its outer surface. Device has two hollow semi-cylinders which connect through Φ-like flanges. This capability is achieved due to use in construction of each semi-cylinder of two coaxial semi-pipes, supported by their edges by setting grooves of flanges, containing elements for pressurization and centering. |
 Radiochemical method for monitoring fast neutron flux / 2286586Proposed radiochemical method involves irradiation of active material in the form of microcrystalline powder of dehydrated alkali metal oxalate by fast neutron flux. Radioactive gaseous products of nuclear reactions which are, essentially, inert gases are separated from active material and their disintegration is recorded. Used as alkali metal are lithium isotopes 6Li or 7Li, or their mixtures, sodium isotope 23Na, potassium isotopes 39K and 41K, or their mixtures, rubidium isotopes 85Rb and 87Rb, or their mixtures, or cesium isotope 133Cs, as well as beryllium isotope 9Be, magnesium isotope 26Mg, calcium isotopes 40Ca, 42Ca, 44Ca,46Ca, and 48Ca, or their mixtures, strontium isotope 88Sr, or barium isotope 138Ba. Respective radioactive isotopes of helium, neon, argon, krypton, or xenon are used to produce inert gas. Gaseous radioactive products of nuclear reactions are separated from active material due to diffusion. Mean size of powdered microcrystals, their amount, and rate of transfer of separated radioactive inert gas to point of recording its decomposition are chosen bearing in mind that total mean time of radioactive inert gas escape from active material up to initial moment of recording radioactive material disintegration should be shorter than half-life period of radioactive inert gas. |
| Method for calibrating nuclear reactor neutron flux density measuring channel in absolute units of power / 2312374 Proposed method for calibrating channels designed for measuring nuclear power plant neutron flux density in absolute units of power includes evaluation of maximal linearity range of mentioned measuring channel wherein calibration is made whereupon positive step-by-step variation in reactivity of nuclear reactor held in subcritical or critical condition is introduced to transfer reactor to supercritical condition with power rising continuously; in the process neutron flux density and medium temperature of nuclear reactor are measured and recorded; then results obtained and transient equations of nuclear reactor kinetics are used to calculate variations in reactivity with time including corrections for temperature effect of reactivity; maximal measurement range for neutron flux linearity is set considering stability of calculated reactivity in this range including corrections for temperature effect; then absolute power of reactor is measured for one value of neutron flux density within mentioned linear range, and absolute value of reactor power is measured by way of foil activation or calorimetry. |
 Device for measuring correlations in neutron decay / 2323454Device for measuring correlations in neutron decay contains a winding of electric magnet, a vacuum chamber and detectors for registration of electrons or protons, emitted during decay of neutrons, a central unit, made in form of vertical rod which carries winding mounting elements, cooling tubs and heat screens; the winding of the electric magnet is made in form of a set of identical vertical circular windings, the circular windings contain channels for injection of liquid helium and are connected to circular forcing collector which is positioned below the anchor ring of windings; the vacuum chamber is made in form of two vertical hemispheres, which are hermetically connected by means of flanges to vertical circular cowling with the central unit rod fastened in it diametrically, it envelopes the windings of the electric magnet with elements of the cryogenic system and contains windows for connecting horizontal vacuumized neutron conductor; detectors of protons and electrons are composed of three independent sections, where first and second sections of detectors are made in form of two flat mosaic sets of scintillators, positioned above and below the beam of neutrons close to the point of its closest proximity to the vertical axis of the system, and third section of detectors is made in form of a sandwich of two combined identical vertical plates of scintillators with an intermediate deflecting screen, positioned on the other side of the vertical rod relatively to first two sections of detectors and perpendicular to the axis of the neutron beam. |
 Method of recording neutron pulsed flow and neutron detector / 2332689Invention relates to metrology, namely, to recording a pulsed neutron radiation in the presence of gamma-radiation and can be used in nuclear reactor control and protection systems or those of critical assemblies and other neutron sources. The invention novelty consists in using the said flow to affect a sensitive element incorporating a neutron-induced fission material. The sensitive element heat energy is converted into electrical signal with parameters allowing estimating those of the recorded flow. The said sensitive element is made from the shape memory material, while conversion of thermal power into electrical signal is effected by step-by-step conversion of thermal energy into mechanical energy of shaper recovery to be converted, further on, into electrical signal. The latter conversion is effected using piezoelectric converters arranged at a preset distance from the said sensitive element. |
 Method of registering neutrons in presence of gamma radiation / 2351953Gamma radiation is constantly checked using neutron detector. Thus measuring of the direct current Iγ arising in the neutron detector under influence of gamma radiation is carried out. The following values are used: for determination and installation of such threshold of discrimination which provides peak efficiency of the detector at the power of exposition dose of gamma radiation which are taking place in current cycle of measuring. For determination of a degree of decrease in the relative efficiency of the detector under influence of gamma radiation and its reduction to greatest possible; for determination of exposition dose power of gamma radiation. |
 Prismatic detector / 2356068Invention relates to registration of ionising radiations, detection of ionising radiation sources at checkpoints, railway and airport terminals, customs posts etc. The ionising radiation prismatic detector features scintillating elements representing equilateral triangle-section rods in a row in parallel and back-to-back. Note that, between their apexes, there is a similar row of triangular-section rods and, in parallel and in mirror-like manner, another two rows of rods are arranged. |
 Method and device for measuring spectral and integral density of neutron stream / 2390800Method of measuring spectral and integral density of streams of neutrons involves using several neutron radiation detectors connected in parallel, which have different dependency of sensitivity on neutron energy. Output signals of these detectors are processed together using a neural network specially trained using simulation modelling, providing computational reconstruction of the energy spectrum of the measured stream of neutrons and calculation of integral density of the measured stream of neutrons and derivative values from the said energy spectrum. The detectors themselves are selected such that their spectral characteristics of sensitivity jointly cover the entire energy range of the measured neutron streams. The device which implements the given method consists of a detection unit and a measurement panel. The detection unit consists of neutron radiation detectors connected in parallel, having different dependency of sensitivity on neutron energy and connected in series to amplifier-normalisers of output pulses of the detectors. The measurement panel consists of a controller, a control console, a display device and a signalling device. The microcontroller itself emulates a neural network specially trained for reconstructing the energy spectrum of the neutron streams. |
 Apparatus for measuring neutron lifetime / 2408904Device for measuring neutron lifetime has a source of a formed beam of neutrons, a neutron guide, an electromagnet and electron detectors. The electromagnet is in form of a combination of a multi-pole lens and two magnetic coils which are coaxially fitted on the input and output of the lens, having cylindrical vacuum chamber with thin frontal walls and flanges for connection to the neutron guide, inside of which, in the region of the coils, there are two proportional electron counters in form of gas-filled discs with thin walls whose material has minimal neutron-absorption cross-section. The lens is placed coaxially with the neutron beam. |
 Method of detecting slow and fast neutrons in intense external radiation conditions / 2414725Method of detecting slow and fast neutrons in intense external radiation conditions, characterised by the direction of the beam of neutrons into a detector which has a housing in form of a cylindrical pipe filled with gas, inside of which an anode is placed in the middle and a cathode is placed on the contour of the pipe, where the cathode is connected to a high voltage line, and an insulator which separates the cathode from the housing, distinguished by that the beam of neutrons enters the detector through an input window made from beryllium and the detector itself can function in such a way that electrical signals are generated locally on the anode surface. |
FIELD: physics, optics.
SUBSTANCE: invention relates to a method of determining spectral and spatial distribution of photon flux of deceleration radiation in at least one spatial direction (x, y, z). The method is carried out by measuring neutrons obtained when deceleration radiation photons (ph) fall on at least one conversion target (5) which is moved in said direction (x, y, z).
EFFECT: shorter measurement time.
7 cl, 5 dwg
Field of techniques and technology
The present invention relates to a method of definition of spectral and spatial distribution of the photon bremsstrahlung, as well as the appropriate device.
The invention is used, for example, in the field of x-ray, medical devices receive images, imaging, non-destructive studies of radioactive objects, production of neutron flows of high intensity, etc.
Getting neutrons using electron accelerator is a known technology that allows us to achieve a strong neutron flux. Getting neutrons of electrons is realized by means of a beam of photons: neutrons coming from the accelerator, get to the first target, called brake target, which emits photons, then emitted thus photons are sent to the second target, called conversion targets, which emits neutrons.
In the framework of the measurement technology, which uses such accelerators of electrons, it is necessary to know the spectral and spatial distribution of the emitted photons, as well as the behavior of a system consisting of a detector and electronics of data collection.
Way in accordance with the present invention allows to satisfy this need.
Disclosure of the invention
The object of the present invention is a method of definition of spectral and spatial distribution at least along one axis, the photon flux braking radiation generated by the interaction of pulses of electrons on the brake target. The method includes:
- at the first point of the axis first measurement of neutrons that occur as a result of integration of signal detection and counting of neutrons, with each signal detection and counting of neutrons produced as a result of falling photon bremsstrahlung at first conversion target, to center the specified first point, with the first conversion target is sensitive to photons with energy, essentially exceeding the first energy threshold, while neutrons are involved in the formation of signal detection and counting, detect and count in the time the interval concluded between two consecutive pulses of electrons,
- move the first conversion targets at different points axis measurement of neutron corresponding to the measurement of neutrons in the first point of the axis, is produced in each of the various points on the axis, and
- the sequence of measurements of neutron corresponding to the dimensions specified in the first point and in these various points, using a sequence of different conversion targets related to energy thresholds that are different from each other and different from the first energy threshold.
The object of the present invention is a device for determination of spectral and spatial distribution, at least along one axis, the photon flux braking radiation generated by the interaction of pulses of electrons on the brake targets, wherein contains:
system conversion and detection of neutrons containing at least two conversion targets, each of which is made with the possibility of generating neutron induced by the action of the photon bremsstrahlung, each of the conversion target is sensitive to the photons with energy, essentially exceeding the energy threshold, different conversion from one target to another, and the unit of measurement, which contains one or more detectors helium 3 is Not for detection and counting induced by neutrons generated by each of the conversion target this detectors on helium-3 are Not in neutron moderator, and the moderator of neutrons surrounded by thermal neutron absorber, with every conversion target consistently positioned on the side of the sink thermal neutrons, addressed to brake target
- electronic the treatment scheme, which processes the signals from the system conversion and detection of neutrons, with electronic processing circuit contains tools for managing detection and counting of neutrons in time intervals concluded between two consecutive pulses of electrons, and
- tools for moving system conversion and detection of neutrons along the axis.
The advantage of this method in accordance with the present invention is identifying and checking in online mode normal operation and neglect of electron accelerator. Preferably measurement of neutron allows to determine the stability of the photon beam, at least in its integral aspect, that is, its intensity and energy (i.e. its capacity).
Preferably way in accordance with the present invention allows also to obtain the characteristics of photon component by measuring the neutron induced component (coefficient of contrast enhancement).
Normal spatial characteristics of photon flux produced using the method in accordance with the present invention allows to optimize the conversion target, intended for the production of neutrons.
In addition, it is known that direct request using photon beam aimed at characterized the material is of particular interest. Preferably, a normal characteristic photon bremsstrahlung beams, achieved using the method in accordance with the present invention allows to obtain the best results for the characterization of materials. In particular, it allows to optimize and reduce the time dimension and, consequently, to reduce costs.
Brief description of drawings
Other characteristics and advantages of the invention will be more evident from the following description of the preferred option of carrying out the invention with reference to the attached drawings, in which:
figure 1 - the device for realization of the method in accordance with the present invention;
figure 2 - perspective view of the block of measurement of a neutron used in the device in accordance with the present invention, shown in figure 1;
figure 3 - example of a stand move, used to implement the process in accordance with the present invention;
figure 4 - example of spectral and spatial distribution of the photon bremsstrahlung obtained using the method in accordance with the present invention;
figure 5 - example of the ratio R, we obtain for different values of the energy of the photon bremsstrahlung and various standardized values of the measured signal.
All the figures of the same elements denoted by the same positions.
A detailed description of the preferred option of carrying out the invention
Figure 1 shows a device to implement the process in accordance with the present invention.
The device includes a tool for creating photon bremsstrahlung and the means to measure at least along one axis of the space of spectral and spatial distribution thus created photons.
A tool for creating photon bremsstrahlung contains 1 accelerator electron and bremsstrahlung target 2, mounted in the holder 3 target. Accelerator 1 emits electrons in the form of impulses. The pulse frequency is, for example, from 10 Hz to 300 Hz and the pulse width is equal, for example, 4.5 ISS. Electrons have energy equal to, for example, 6 MeV, 9 or 11 MeV MeV. Interacting with the brake target 2, for example with a tungsten target, electrons produce photons ph bremsstrahlung.
A tool for measuring the spectral and spatial distribution of the photon beam system contains 6 conversion and detection of neutrons and electronic chart 9 processing, the system 6 conversion and detection of neutrons contains at least two conversion targets 5 and block 10 of measurement this conversion targets are established one after another in block 10 of measurement. Each conversion target made with the possibility of generating neutron induced beyond a certain energy threshold photon beam ph, this is associated with a target energy threshold differs from one target to another. Block 10 of measurement measures the neutrons produced each conversion target 5. Unit of measurement 10 contains one or more detectors 8 running on helium 3 is Not contained in the 7 moderator of neutrons, which is surrounded by absorber 4 that absorbs thermal neutrons (neutrons of very low energy). Designed block of the detector is sensitive only to the fast neutrons and therefore only slightly influenced by the environment and the influence of slowdown that it has on the neutrons.
Conversion target 5 set on the side of the absorber 4, addressed to brake target 2. As shown in figure 2, the conversion target 5 position with alignment on the side of the absorber 4 to optimize the detection of photons ph. Perpendicular side 4 in the Central point of the conversion target 5 specifies the axis X. According to the preferred option of carrying out the invention helium detectors 8 grouped in pairs and form a three-channel measurement - one front channel, and the two rear channels. The electronic scheme 9 processing is fast electronic device that for each measurement channel i (i=l, 2, 3) contains amplifier type AND ADSF(1=1, 2, 3) (ADSF is short for "amplifier-discriminator threshold-box").
Measurement of neutrons produced in the time intervals that allow you to neglect the photon bremsstrahlung radiation emitted during the electronic impulses. Preferably these intervals chosen so as to provide enough time for neutron detectors and electronic processing circuit that these detectors and these schemes can fully show their discovery properties.
Indeed, the photon bremsstrahlung occur almost instantaneously during the interaction of electrons with brake target 2. Thus, the photon bremsstrahlung radiation emitted with the same timing as the electrons, that is, with the same width and with the same frequency. Consequently, these photon bremsstrahlung are present during the entire width of electronic impulses, which usually varies from a few microseconds to several tens of microseconds. During the e-pulse neutron completely blinded the resulting photon momenta and, therefore, do not work. Only a few tens of microseconds after the termination of the photon pulse neutron restore all its properties. Thus, the measurement of the photon and neutron component occurs only between photon momenta and preferably in the time intervals selected so that electronics processing could show their discovery properties. For this electronic circuit 9 processing includes tools M-management, which serves the command on the electronic discovery, which blocks the detection and counting of neutrons outside these time intervals. When this provision system 6 conversion and discovery of the neutron measurement cycle includes the integration of a sequence of signals detection and counting of neutrons measured between successive pulses of electrons.
For example, but not limited to, the measurement is carried out at a frequency of the electrons is equal to 90 Hz, with produce 5400 measurement cycles, and the time of data collection through a single channel measurement is 10 ISS.
Provide tools that help you to move the system 6 conversion and detection of neutrons at least along one axis of space. The movement of produce, for example, in at least one of the three perpendicular directions of space formed by direct trihedron (x, y, z), and the x axis is defined above axis. As an example, figure 3 shows the stand In a move that is managed remotely and moving system 6 conversion and detection of neutrons along the y-axis with the step of 50 mm between the first extreme position And located on -500 mm in relation to the Central position of the abscissa y=0, and the second extreme position U, located on +500 mm in relation to the Central position.
Conversion target 5 made from a material that is capable of generating induced by neutrons beyond a certain energy threshold of the photon beam ph and therefore beyond a certain energy threshold of electrons e - . Thus, consistently choose a different target, adapted to different energy thresholds of electrons to implement the process in accordance with the present invention, which allows to determine the distribution of photon flux in a wide energy range. Target 5 can be, for example, a target of uranium 238 U values of the electron energy in excess of 6 MeV, and a target of beryllium Be for energy values exceeding 1,67 MeV.
Figure 4 shows an example of spectral and spatial distribution obtained using the method in accordance with the present invention. The detector on helium 3 is Not equipped with a conversion target of uranium 238 U, move in front brake target along the y axis, which is removed on the merits of 1 m from the brake target 2. Moving targets are carried out between the marks -500 mm, and +500 mm with the step of 50 mm (see figure 3). The target is a uranium plate round shape, the radius of which is essentially equal to 50 mm, thickness of which is essentially equal to 3 mm the energy of the electrons is essentially equal to 9 MeV. Figure 4 shows the number of pulses detected helium detector, depending on the angle q aperture of the beam (the angle between the x axis and the axis determined brake target 2 & target 5).
Figure 5 for the different values of the electron energy shows the ratio R at different normalized values of the signal, measured by the method in accordance with the present invention, depending on moving targets measurement. Under this provision the device of measuring the value of R is equal to the value of the signal, measured at a given position divided by the maximum value of a signal, measured at all positions. Moving target measurement shall be along the y axis, which is removed on the merits of 1 m from the brake target 2. Moving targets are carried out between the marks -80 mm and +80 mm with a step of 10 mm Curves C1, C2 and C3 correspond to the energy of the electrons is equal to 6 MeV, 9 MeV and 11 MeV. The resulting profile is uniform for all values of energy.
The results, shown in figure 4 and 5 relate to the case when the target of the 5th dimension is the target of uranium 238 u As indicated above, such a target is preferably used for values of the electron energy greater than or equal to 6 MeV, which is the threshold energy of the isotope 238 u For energy values below 6 MeV use other targets such as targets of beryllium Be.
1. Method of determination of spectral and spatial distribution at least along one axis of the photon flux braking radiation generated by the interaction of electronic pulses with brake target (2)where: at the first point of the axis perform the first measurement of the neutron by integrating signal detection and counting of neutrons, the signals detection and counting of neutrons get when hit photons (ph) bremsstrahlung at first conversion target (5), centered on specified to the first point, and the first conversion target is sensitive to photons with energy, essentially exceeding the first energy threshold, while detect and calculate the neutron involved in the formation of signal detection and counting, in the time interval concluded between the two serial electronic pulses, consistently move first conversion target (5) in different points of the axis, with each of these different points of the axis perform the measurement of the neutron corresponding to the specified dimension of neutrons in the first point on the axis, and perform a sequence of measurements neutron corresponding to the dimensions specified in the first point and in these various points, with many different conversion targets, with an energy threshold that is different for different targets and different from the first energy threshold.
2. The method according to claim 1, wherein the first conversion target is a beryllium target with the first energy threshold, and the second conversion target is the target of uranium 238 U with the second energy threshold for having a value greater than the value of the first threshold.
3. The method according to claim 1, wherein at the specified time interval and at each point of the axis in the absence of conversion targets to measure neutron signal characteristic of the accelerator (1) of electrons that create the photon bremsstrahlung in the interaction of electrons with brake target (2), the measurement of neutron signal typical for electron accelerator, subtract from signal detection and counting of neutrons measured in the presence of the conversion of the target.
4. The method according to claim 1, wherein the signal detection and counting is measured by the detector unit operating on helium 3 is Not.
5. Device definition of spectral and spatial distribution at least along one axis of the photon flux braking radiation generated by the interaction of electronic pulses with brake target (2)are characterized by the fact that contains: system (6) conversion and detection of neutrons, containing at least two conversion target (5), each of which is made with the possibility of generation of neutrons under the action of the photon bremsstrahlung, each of the conversion target (5) is sensitive to photons with energy, essentially exceeding energy the threshold differs for each of the conversion of the target, and block (10) measurement, which contains one or more detectors (8) for helium 3 is Not for detection and counting of neutrons produced for each of the conversion of the target, with detectors (8) for helium 3 are Not a moderator (7) of neutrons, and the moderator (7) neutrons surrounded by absorber (4) thermal neutrons, each of the conversion target (5) consistently positioned on the side of the absorber (4) thermal neutrons, addressed to brake target (2), electronic circuit (9) processing is made with the possibility to process the signals coming from the system (6) conversion and detection of neutrons, while the electronic scheme (9) processing contains tools for managing detection and counting of neutrons in time intervals, concluded between two consecutive electronic impulses and means (I) to move the system (6) conversion and detection of neutrons along the axis.
6. The device according to claim 5, which means () to move the system (6) conversion and detection of neutrons along the axis contain the stand (In) displacement, managed remotely.
7. The device according to claim 5 or 6, in which the first conversion target is a beryllium target with the first energy threshold, and the second conversion target is the target of uranium 238 U with the second energy threshold exceeding the threshold.