The x-ray source
(57) Abstract:The invention relates to x-ray techniques and can be applied in radiation technologies, preferably those that require high pulse dose bremsstrahlung radiation with quantum energy up to 10 MeV in excess of 106times the average dose source that will find wide application in food, chemical and medical industries. The invention is: to increase the working life of the source, containing powerful pulse frequency generator 1 of the electron beam 2, the target is made in the form of carbon substrate 4 coated by electron beam generator layer 3 of metal or carbide. The metal layer may be applied in powder form mixed with carbon, taken in equal amounts. The metal layer can be protected from the generator beam carbon coating 5. In such a target function of the Converter energy beam bremsstrahlung performs a layer of metal, the mechanical load is carbon substrate having a high resistance to heat shock, carbon coating 5 protects the metal layer from sputtering, the admixture of carbon in the metal layer from slavleniyachrist for x-ray radiation. 1 C. p. F.-ly, 2 Il. The invention relates to x-ray techniques and can be applied in radiation technologies, preferably those that require high pulse dose bremsstrahlung radiation with quantum energy up to 10 MeV in excess of 106times the average dose source that will find wide application in food, chemical and medical industries.The known x-ray source containing electron accelerator high energy, a device for release of electrons into the atmosphere and the target is cooled by air flow 
The disadvantages of this source are small resource targets and the complexity of the design due to the use of the discharge device.The known x-ray source that contains a powerful pulse frequency generator of the electron beam and a target made of metal with a large nucleus charge Zmthe thickness of the lmnot exceeding the length of the path of the electron beam in the target material  the Target is located in the vacuum chamber of the accelerator and is cooled due to heat radiation.The disadvantages of this source are small size allowable density allocated to the target average power of the beam, higher than average in 106and more times. At such high pulse power tantalum target "floats", tungsten crumble.The technical result of the invention is to increase the allowable density allocated to the target average power of the beam, and resource its work.The technical result is achieved in that in the x-ray source that contains a powerful pulse frequency generator of the electron beam and a target made of metal with a large nucleus charge Zmthe thickness of the lmnot exceeding the length of the path of the electron beam in the target material, the target is made in the form of carbon substrate coated by electron beam generator is working layer of the same metal, and the thickness of the substrate lpselected from the condition lp< lmm/pwherem,pthe density of the metal target and the substrate (carbon), respectively. In addition, the working layer is made of a carbide of the same metal or of a mixture of the same metal with carbon and/or work on the metal layer from the generator e-beam deposited carbon coating, whose thickness lpokselected from the conditions lpok< lm.In this con is nenovski radiation, and the graphite substrate, which has a higher resistance pulse thermal conditions, carries the mechanical load. Mixing metal with graphite prevents the "fluidity" of metal as a whole. The presence of carbon coating prevents metal sputtering. High transparency of carbon for electron and x-ray radiation allows to get almost the same output x-ray radiation, as in the case of a pure metal target. Thus, the use of carbon components in the target allows to significantly increase the allowable density of emitted energies and its resources due to the high resistance carbon components to pulse effects, and due to its higher degree of thermal radiation.In Fig.1 and 2 presents the x-ray source, options.The source has a pulse frequency generator 1, an accelerating electron beam 2 and the target, consisting of a working layer 3 of metal, carbon substrate 4 and the carbon cover 5 (Fig.2). The source of the electron beam 2 and the target are located in a vacuum chamber. The target is the anode of the electron beam generator. The metal layer 3, performs the function of the Converter is raised from the condition of maximum x-ray output. Usually applied tungsten or tantalum, with a large Zmand high melting temperature, the thickness of the layer lm0.5 1 run length of electrons, which is determined by the energy of the electrons. The thickness of the carbon substrate lpmade from the most durable grades of graphite or carbon tissue is selected from the conditions of ensuring the mechanical strength with minimum absorption of x-rays:
lp< lmm/pin the case of tantalum (= 16.6 g/cm3) or tungsten ( = 19.3 g/cm3) lp< 17 lm.There are currently a number of technologies deposition of metals on the surface of graphite, for example, impregnation of graphite, as is done in the manufacture of brushes of electric motors or by using a torch and so on, the Metal may be deposited on a substrate in the form of a powder mixed with carbon, taken at approximately the same volumes. When the carbon prevents fusion of metal and change the shape of the working layer of metal, as is the case of pure tantalum plate. The graphite component of the mixture has virtually no effect on the magnitude of the output x-ray radiation. Work the metal layer can be protected outside the metal lpok< lmeth. Carbon coating inhibits erosion of the metal and at such thickness is almost transparent to the electron beam.The source operates as follows.When enabled, a pulse generator 1 electron beam 2, bombarding the target is absorbed by the working layer 3 of metal, which is a source of hard bremsstrahlung. At high electron energy (greater than 1 MeV) bremsstrahlung x-rays are directed mainly towards the spread of the electron beam and almost passes through a carbon substrate 4. The vacuum chamber has an exhaust port located opposite substrate 4. Depending on the scheme of the electron beam generator, the target can have zero or high positive potential.Consider a specific example of the operation of the x-ray source, which uses a pulse frequency generator of the electron beam on the basis of the plasma current interrupter with the following parameters: pulse frequency of 2 Hz, the energy of the electron beam of 3 MeV, beam current of 20 kA, duration 100 NS, pulse beam power 6 1010Watts, average 12 103W. The path length of electrons for tungsten or tantasy 0.8 mm (1.3 g/cm2).As the substrate 4 was used three layers of graphite cloth with a total thickness of 1.5 mm, which provides the necessary mechanical strength and with a large margin satises the bandwidth of x-ray radiation. As a working layer of metal is applied carbide powder tantalum thickness of 1.5 g/cm2or "sponge" from a tungsten wire with a diameter of 0.04 mm with a mass thickness of 1.3 g/cm2(used defective spiral bulbs). As carbon coatings using carbon cloth with a thickness of 0.5 mm (0.3 g/cm2). The dose rate of x-ray radiation at a distance of 0.5 m from the target was the same value of 0.25 kGy/h as in the case of the prototype (tantalum or tungsten plate 0.8 mm), and in the case of the above options target for the circuit of Fig.2. Resource targets of the pure metal at an average power density of 20 W/cm2approximately 1 h: tantalum plate "fused", tungsten crumble. The proposed target has worked 200 hours at an average power density of 50 W/cm2no visible signs of destruction.Thus, the proposed scheme targets allows to double the average density allocated to n is containing a powerful pulse frequency generator of the electron beam and the target material with high atomic number zmand high melting temperature of a thickness of lmnot exceeding the length of the path of the electron beam in the target material, wherein the target is made in the form of a working layer, placed on a carbon substrate, the thickness of which is selected from the condition
wherem,pthe density of the material of the active layer of the target and the carbon substrate, respectively,
as a material of the active layer of the target used metal or carbide of a metal or a powder mixture of metal with carbon in equal volumes.2. Source under item 1, characterized in that on a work target layer from the incidence of the electron beam deposited carbon coating, the thickness of the lpabouttowhich is selected from the condition lpaboutto< lm.
FIELD: mechanical engineering; radiation method of inspection of materials and items.
SUBSTANCE: centering mount has housing inside which the laser is disposed as well as first reflector mounted onto axis of laser in front of exit window of X-ray radiator is the point where axis of laser crosses axis of X-ray beam, second reflector mounted onto axis of laser outside the projection of exit window of X-ray reflector for rotation relatively axis being perpendicular to plane formed by axes of laser beam and X-ray. Device also has aids for indicating focal length made in form of pointer provided with scale fixed onto housing of centering mount. Flat collimated laser beam forming system is mounted in front of laser. Laser beam propagates along plane being parallel to vertical plane crossing longitudinal axis of X-ray radiator. The axis is at the same time perpendicular to vertical plane crossing axis of X-ray beam. The second reflector is mounted at the exit of system at laser axis. Beam splitter is mounted between first and second reflectors. In front of the beam splitter there is the second semiconductor laser which is mounted onto axis being perpendicular to axis of laser to cross its point of crossing with beam splitter.
EFFECT: improved precision of measurements; simplified application.
FIELD: roentgen engineering; producing roentgenograms, for instance in medicine.
SUBSTANCE: proposed X-ray source module has X-ray tube incorporating body, cathode and anode assemblies, as well as generator unit incorporating high-rating voltage divider whose high-voltage lead is connected to one of tube assemblies; X-ray tube body is made in the form of metal cylinder accommodating sectionalized cylindrical high-voltage insulator. One of its ends is connected through vacuum-tight joint to one of body ends and other end mounts cathode assembly. Anode assembly is disposed on other end of body and is made in the form of anode tube brought outside the body that carries target on its loose end. Generator unit is disposed inside cylindrical high-voltage insulator whose inner space is filled with oil. Side surface of insulator functions as high-rating voltage divider.
EFFECT: reduced mass and size of module.
1 cl, 1 dwg
FIELD: roentgen diagnostics and therapy in medicine and various processes including flaw detection and scientific research.
SUBSTANCE: proposed X-ray pulse generator has X-ray tube effective surface area of whose point cathode and anode is not over 10-6 m2 and preset cathode-to-anode distance is minimum, 10-3 m; it also has high-voltage pulse generator whose heavy-current high-voltage pulse shaper is made in the form of heavy-current high-voltage vacuum or gas-discharge switching unit incorporating electrode that controls switching unit triggering and is provided with additional high-voltage filter inserted in its circuit. Linear size of X-ray radiator focal spot is 0.1-0.5 mm. X-ray quanta energy can be regulated between 20 and 150 keV; X-ray pulse length is about 10-8 to 10-6 s.
EFFECT: reduced size of X-ray tube.
1 cl, 1 dwg
FIELD: radiator positioning to object.
SUBSTANCE: newly introduced in proposed laser positioner are beam splitter disposed on laser axis between first reflector and first butt-end of laser at angle of 45 deg. to it axis, as well as third reflector disposed on axis drawn between point of intersection of beam splitter reflecting surface and laser axis perpendicular to this axis; beam splitter and third reflector are rigidly intercoupled and mounted on revolving flange whose axis is aligned with laser axis; it is set in rotary motion by means of motor drive, for instance that of frictional type, at frequency f ≥ 10 Hz mounted on positioner housing; reflecting surface of third reflector is tilted through angle β = 45° + α/4 to laser axis, where α is X-ray radiator angle of radiation; distance C between centers of beam splitter and third reflector is correlated with distance B along laser axis from center of first reflector to that of beam splitter by equation C=(A-B)·tg(α/2), where A is distance from X-ray radiator focus to first reflector center. This positioner incorporates provision for estimating X-rayed area of object and also for determining center of this area.
EFFECT: enlarged functional capabilities and facilitated determination of radiator-to-object distance.
1 cl, 1 dwg
FIELD: positioning radiator with respect to object.
SUBSTANCE: newly introduced in proposed positioner are optical wedge installed on laser optical axis for rotation relative to this axis at frequency f ≥ 10 Hz and at distance A from intersection point of X-ray beam and laser axes that equals distance from this point to X-radiator focus; drive for rotating optical wedge; first beam splitter installed on laser optical axis between optical wedge and first butt-end of laser at distance C > A from center of first reflector and at angle β < 45° to laser axis perpendicular to plane formed by laser and X-ray beam axes; second beam splitter made of plexiglas and installed on X-ray beam axis past first reflector at distance B from its center perpendicular to plane formed by X-ray beam and laser axes at angle γ to X-ray beam axis. Distances B and C as well as angles β and γ are interrelated by equations γ = 45° - β and β=c·tg(2β); optical wedge parameters (angle at θ vortex, ray deviation angle δ, and wedge material refractive index) are interrelated by equations δ = θ(n - 1) and δ = α/2, where α is X-radiation angle. This positioner enables estimation of X-rayed object area and also determination of center of this area.
EFFECT: enlarged functional capabilities, facilitated determination of distance from radiator to object.
1 cl, 4 dwg
FIELD: positioning radiator with respect to object.
SUBSTANCE: additionally introduced in positioner is rotor in the form of hollow cylinder revolving at frequency f ≥ 20 Hz whose axis of revolution is aligned with laser axis; rotor is disposed between first reflector and laser; optical raster in the form of combination of transparent and nontransparent bars of width t and height H is set on rotor butt-end disposed closer to laser; bar width is chosen from condition t = λ/sin(α/2, where λ is laser beam wavelength; α is X-radiator ray angle; bar height is chosen from relation H ≤ d, where d is laser beam diameter; mounted on other end of rotor is mask with central hole and two symmetrically disposed holes spaced apart through distance D; rotor length B on laser axis is found from expression B=kd/tg(α/2), where k = 1 - 2 is process coefficient and diametric line connecting centers of mask holes is perpendicular to direction of raster bars; distance A between raster and center of first reflector along lather axis equals distance from this center to X-ray tube focus on X-ray beam axis. Such positioner enables X-raying of object area as well as determination of center of this area.
EFFECT: enlarged functional capabilities and facilitated determination of distance from radiator to object.
1 cl, 4 dwg
FIELD: technology for orientation of x-ray emitter relatively to the object.
SUBSTANCE: laser localizer additionally comprises optical pattern, consisting of 4 groups of identical transparent and nontransparent bars with width t and height H, bars of each group are turned in pattern plane by 45° relatively to bars of adjacent groups and positioned symmetrically to laser axis, pattern is mounted on laser axis perpendicularly to it, in front of the pattern between it and the first deflector on the laser axis perpendicularly to it a nontransparent screen is mounted for screening laser rays of highest diffraction orders, screen having one central aperture for passage of laser rays of zero diffraction order and eight apertures for passage of laser rays, diffracted into ±1 diffraction order, which are positioned on the screen at certain diameter with 45° interval from each other and spatially combined with position of corresponding diffraction maximums of ±1 order in pattern plane.
EFFECT: defined area of the object being x-rayed, simplified procedure for determining center of the zone.
FIELD: medical engineering.
SUBSTANCE: device has tripod bearing X-ray therapy tube having radiation source and radiographic cone. The cone has cylindrical part having flange at one end provided with fastening members to be fixable in the X-ray tube and conic part on the other end. Protective lead aperture is available on the same side with the flange. Its inlet orifice diameter is less than the outlet orifice diameter for producing divergent conic X-ray beam. A through opening is available in the cylindrical portion of the X-ray cone arranged at an angle of 45-50° to its axis with laser radiator being placeable into it.
EFFECT: enhanced effectiveness in carrying out one-stage radiation therapy and laser radiation therapy of malignant diseases.
FIELD: physics; X-ray inspection.
SUBSTANCE: X-ray generator includes high DC voltage generator, X-ray tube in the form of a metallic enclosure, anode assembly with a target anode and window for the X-ray radiation output, cathode assembly in the form of a cathode with a filament and a cathode insulator, cathode filament power supply unit; the high DC voltage generator and the cathode filament power supply unit are located in the internal cavity of the cathode insulator, filled with dielectric material.
EFFECT: decrease in dimensions and weight and increase in reliability of device as whole.
2 cl, 1 dwg
SUBSTANCE: invention can be used for generating x-rays of high and/or low energy. The essence of the invention consists in that the electric power supply of the electron gun feeds the tube for the linear acceleration under the control of a control system, the microwave power supply accelerates the electron beams, generated through a tube for linear acceleration of electrons under the control of a control system; the tube for the linear acceleration of electrons is connected correspondingly to the electric power supply of the electron gun and the microwave power source for the generation of electron beams of high energy, the high-voltage power supply of the electron gun feeds the high-voltage electron gun under the control of a control system, the high-voltage electron gun is connected to the high-voltage power supply of the electron gun for generating electron beams of low energy, the object of radiation thus accepts electronic beams of high energy for generating X-rays of transfer of high energy, and/or accepts electronic beams of low energy to generate X-rays which reflect low energy. Technical result consists in the development of an extractor of X-rays of high and/or low energy, because of which is ensured the high quality of the forming of images and the large scale of regulation of electron beams.
EFFECT: ensuring the improvement of the quality of forming images and a large diapason of regulating of electron beams.
10 cl, 4 dwg