Spherical cold neutron moderator
SUBSTANCE: auger unit is replaced with a funnel with an outlet tube with a special shape, placed in the bottom end part of a moderator chamber and providing quasi-uniform release of spheres under the force of gravity. The average frequency of release of the spheres is defined by the diameter and length of the neck of the funnel and its angle of inclination to the horizontal.
EFFECT: simple design of the unit due to continuous removal of spent spheres from the moderator chamber and high reliability and long service life thereof.
1 cl, 2 dwg
The invention relates to inhibitors of neutron research reactor and neutron-producing target accelerators, and is intended for receiving the external neutron beams of low energy (cold neutrons). In most cases, the active ingredient of cold moderators are hydrogen-containing substance in the liquid phase, but to achieve low temperatures is the use of substances in the solid phase (methane, aromatic hydrocarbons, solid deuterium). Solid hydrogenous substances subject to strong radiation decomposition under the action of fast neutron source, with the attendant undesirable effects. Therefore, the substance of the retarder must be periodically replaced with fresh, the neutron source has to halt, if the replacement is made simultaneously throughout the chamber of the retarder. The dispersed, ball structure of the working substance of a cold neutron moderator allows continuous shifts slow neutrons substances and allows the use of the retarder indefinitely unlike traditional moderators.
Known ball cold neutron moderator with a continuous change of the solid balls of methane, consisting of the cryogenic chamber of the retarder located near intense source of restricnational - nitrosopropane target accelerator tract continuous supply of fresh solid balls of methane in the camera node removal of the spent balls from the chamber and the regeneration system of methane and production of beads described in the work of A.T. Lucas, G.S. Bauer, C.D. Sulfredge, A pelletized solid methane moderator for a medium-to-high power neutron source, Proc. of the 13th Meeting of the International Collaboration on Advanced Neutron Sources, ICANS XIII, Villigen, Switzerland, November 1995, published: G.S. Bauer, R. Bercher (Eds.), Paul Scherrer Institut Proceedings 95-02, vol. II, 1996, p.644-652.
The outline of this well-known moderator presented in Appendix 1 - camera retarder, 2 - tract fresh balls of generator balls, 3, 4 - site removal of waste beads, made in the form of a screw.
The disadvantage of this device is the presence of mechanical active node of the rotating auger. This determines the unreliability of the auger site because of its work in conditions of strong fields of fast neutrons and a low temperature (20-40 K), and difficult access to prevention, repair or replacement. The failure of the auger site will lead most likely to a complete replacement camera retarder with the adjacent parts of the path of submission and selection of balls.
The objective of the invention is to provide a high reliability of the site selection of the spent balls preserving the continuity and periodicity (or quasi) release the balls from the chamber.
The village is Alanna task is solved by that ball in cold neutron moderator, including cryogenic chamber of the retarder located near intense source of fast neutrons' (for example, a research nuclear reactor or nitrosopropane target accelerator), the generator "fresh" solid balls of slow neutrons substances tract continuous supply of fresh solid balls into the camera and the host of the continuous removal of the spent balls from the camera node to the continuous removal of the spent balls from the chamber made in the form of a funnel with a curved outlet tube at the bottom end of the chamber of the retarder, and the size and shape of the funnel and the outlet tube are calculated by the methods of mathematical modeling of the conditions for ensuring the desired average speed release beads with subsequent experimental validation.
Schematic diagram of the construction of the proposed site, the continuous removal of solid waste balls shown in Fig. 1, where 1 is the cylindrical section (compartment camera moderator), 2 - funnel, 3 - direct a portion of the outlet tube 4 is bent part of the tube 5 is inclined upward part of the tube, α - the angle of the ascending part of the outlet tube.
The principle of the proposed site, the continuous removal of solid waste balls that is. In the chamber of the cold moderator harikesanallur substances (mesitylene, methane) fill the compartments of the chamber of the retarder to a certain height. Under the influence of gravity and the dynamic pressure of flow of the cooling helium through the cone and pipe section of the site selection process, they are removed from the chamber with a defined frequency, and with the same frequency in the camera spiked fresh balls (the principle supply of balls in the chamber can be the same or different; it is not the purpose of this paper), so that the height of the backfill remains constant. The diameter of the discharge tube must be selected so that there are no blockages in the movement of the balls. After passing through the straight part of the tube beads are experiencing gradually increasing the resistance in the curved part of the tube, and then in the course of the inclined part of the tube, the resistance becomes maximum. Thus, by selecting the height and slant of the tube it is possible to achieve a dynamic balance between resistance balls and gravity load from all the balls, filling compartment of the camera. In this case, obviously, the average consumption of balls reaches a stable, desired values.
For the balls of solid methane with a diameter of 4 mm, extracted with average frequency 1 ball/s, figure 1 shows the dimensions calculated by the PCF program, should be approximately the same as in Table 1. Detailed description of the calculation methodology, see what the Annex 2.
|Site settings selection of balls||Size mm|
|The minimum inner diameter of the discharge tube||13 mm|
|The height of the cone plots (L1)||50 mm|
|The height of the straight part of the discharge tube (L2)||30 mm|
|The radius of the curved part of the discharge tube(R)||70 mm|
|The horizontal projection of the length of the portion of the inclined tube (L3)||90 mm|
|Vertical projection length of the portion of the inclined tube (H)||19 mm|
|The angle of the discharge tube (α)||α≈12°|
Schematic diagram of ball offer of a cold neutron moderator with a continuous change of the solid balls of methane is given in Fig. 2, where 1 is the source of fast neutrons, 2 - water prejudicial, 3 - camera cold moderator, 4 - pneumotach fresh balls of methane in the chamber 5 to the generator of the solid balls of methane, 6 - master the ü supply of liquid methane, 7 - liquefier purified gaseous methane, 8 - enriching camera, 9 - heater unit, 10 - tract disposal of waste beads, 11 - cold trap radiolytic hydrogen 12 - helium ventilator, 13 - node dosed selection of exhaust balls from the chamber.
The device operates as follows. From the generator the balls of solid methane 5 (its principle and design not described here) with a certain frequency beads are pneumotach 4 moving cold helium gas To 20-30 in the upper part of the chamber of the retarder 3, immediately adjacent to the neutron source 1 and the water prejuidices 2. The temperature of the helium is supported helium refrigeration machine (not shown) through the heat exchanger 11. To flat bottom rectangular or oval in horizontal section of the chamber adjacent few (3 - 5) funnels conical shape with drainage tubes - site selection 13 (see also Fig. 1). Balls, poured from drainage pipes with a frequency equal to the frequency of submission of fresh balls, common pipe 10 fall within the heating unit 9 with a temperature of 90-100 K, which serves as a separator of radiolytic hydrogen. From block 9 of gaseous hydrogen and helium pumped through a helium liquefier hydrogen 11 is a heat exchanger between the helium refrigerating machine and helium of pneumata the transportation path of the balls of methane. The cooled helium is passed through the path of feed of the balls and the chamber of moderator ventilator-circulator 12. Liquid methane from the heavier products of decomposition from the hopper 9 is poured in enriching the chamber 8 with a temperature of more than 120 K, where the removed gaseous methane after liquefaction liquid nitrogen 7 is returned to the generator 5 through the pipe 6. The cycle repeats.
Reliability of continuous operation of such a retarder is provided by the absence of moving mechanical parts in the zone of high radiation, and the presence of several selected craters in the case of locking balls in one or two selected tubes bulbs will continue to be discharged from the other, and the first performance is easily restored by heating the tubes to the melting point of methane (tubes can be provided with electric heaters).
1. K.D. Wilkinson, A.T. Lucas, A combined H2/CH4cold moderator for a short-pulsed neutron source. Proceedings of the 10th Meeting of the International Collaboration on Advanced Neutron Sources (ICANS X), Institute of Physics Conference Series Number 97, Los Alamos National laboratory. Institute of Physics, October 1988, p.559.
2. H. Stelzer, H. Bamert-Wiemer and N.Bayer. J.Neutron Res., 11 1-2 (2003), p.99. Full Text via CrossRef.
3. G.S. Bauer. Pulsed Neutron Source Cold Moderators: Concepts, Design and Engineering. In: Proc. of International Workshop on Cold Moderators for Pulsed Neutron Sources. ANL, USA, Sept. 29 - Oct. 1997. Edition of the OECD. 1998, pp.27-42.
4. Shabalin, E.P., et al., Pelletized Cold Neutron Moderators for the IBR-2M reactor. In: Proc. of the 6thInternatinal Workshop on UCN& CN Physics and Sources, S. Petersburg-Moscow, 1-7 July 2007: http://cns.pnpi.spb.ru/ucn/articles/Shabalin.pdf.
5. Kulikov, S.A., Shabalin, E.P. "New Complex of Moderators for Condensed Matter Research at the IBR-2M Reactor". Rom. Journ. Phys., Vol. 54, No 3-4, pp.361-367, Bucharest, 2009.
6. Kulikov, S.A., et al., R&D of productive pelletized cold neutron moderators (status), Proc. of the Second Research Co-cordination Meeting, IAEA, Kuala Lumpur, Malaysia, p. 171-175, 2009.
7. Physics of Particles and Nuclei Letters, 2010, Vol. 7, No. 1, pp.57-60.
Ball cold neutron moderator, including cryogenic chamber of the retarder located near intense source of fast neutrons, for example, a research nuclear reactor or nitrosopropane target accelerator generator "fresh" solid balls of slow neutrons substances tract continuous supply of fresh solid balls into the camera and the host of the continuous removal of the spent balls from the chamber, characterized in that the node is continuous removal of the spent balls from the chamber made in the form of a funnel with a curved outlet tube at the bottom end of the chamber of the retarder, and the size and shape of the funnel and the outlet tube are calculated by the methods of mathematical modeling of the conditions for ensuring the desired average speed release beads with subsequent experimental validation.
SUBSTANCE: invention includes an array of sensitive elements and at least two analyser arrays arranged with a different phase and/or periodicity in front of two different sensitive elements. Preferably, the sensitive elements are arranged into micropixels, for example, from four adjacent sensitive elements, wherein the analyser arrays with mutually different phases are placed in front of said sensitive elements.
EFFECT: forming phase-contrast images and enabling sampling of intensity picture readings formed by said device in different positions at the same time.
12 cl, 3 dwg
SUBSTANCE: according to the method of moving a group of opaque microobjects, a light beam with closed regions of zero intensity is formed from multiple beams. First, three coaxial, zero-order Bessel beams with different propagation constants are formed, thereby forming a stable beam in form of a circular spot. These beams are then arranged in space so as to form one or more closed regions for capturing and moving opaque microparticles.
EFFECT: high efficiency owing to automation of the process.
SUBSTANCE: invention utilises the difference in initial kinetic energies of mono- and diatomic hydrogen ions to separate monoatomic ions and obtain an ion beam with high content of the monoatomic component. To this end, an ion source with electron circulation includes additional electrodes - reflector and collector, which form an electrostatic potential barrier which reflects diatomic ions but not monoatomic ions.
EFFECT: invention enables to increase content of the monoatomic component in an ion beam, which can be used to prolong the life and increase reliability of pulsed neutron generators.
5 cl, 3 dwg
SUBSTANCE: invention refers to medical equipment, namely to radiation therapeutic apparatuses. An apparatus comprises an X-ray source with an electronic gun, a target and a electrode potential source of an electronic gun cathode, a resonator arranged along an electron ray and connected to a microwave signal source allowing frequency tuning, a detector of passed pathological radiation material, a frequency recorder. A conductor is introduced to couple a resonator and said target. The resonator is toroidal and has a gap to pass the electron ray, while a distance of the resonator gap and the target is specified provided 1.3>UINπfd/v0|Up|>1.1 wherein UIN is a microwave signal amplitude in the resonator gap, f is a microwave signal frequency, d is a distance of the gap and the target, v0 is an electron flow, Up is a cathode potential of the electronic gun cathode with respect to the resonator.
EFFECT: use of the apparatus provides more complete elimination of pathology of the radiated biological material.
2 cl, 4 dwg, 1 tbl
SUBSTANCE: invention relates to computer tomography. Device for collection of data of tomographic projections in multitude of angular positions relative to an object, located in the examination area, contains radiation source, detector, source and transversal centre of detector being transversally displaced relative to the centre of transversal field of view during collection of data of projections and direction of transversal displacement being tangential with respect to transversal field of view. Methods of computer tomography contains stages, at which first irradiation is emitted from position which is transversally displaced from the centre of transversal field of view, detector of irradiation is used for collection of data of computer-tomographic projections, stages of first irradiation emission and application of irradiation detector for collection of data of computer-tomographic projections are repeated and first set of CT data is reconstructed to form first three-dimensional data. Computer-tomographic device contains roentgen source transversally displaced from rotation axis, roentgen detector, also transversally displaced from rotation axis and rotating relative to rotation axis in state of constant mechanical connection with roentgen source. Roentgen source emits irradiation, characterised by transversal angle of fan beam, and complete taking of angular readings of transversal field of view requires collection of data of projections in larger angle range than 180° plus the angle of fan-beam. Device also contains unit of reconstruction of data of projections for formation of three-dimensional data, characterising transversal field of view.
EFFECT: increase of device efficiency.
39 cl, 9 dwg
SUBSTANCE: method of generating X-rays involves exposing the diffracting layer of a monochromator crystal with initial X-rays and optical radiation in the visible and/or infrared region with intensity which varies along the diffracting layer of the monochromator crystal, where said monochromator crystal is based on a crystal in which under the effect of optical radiation and depending on the optical radiation, interplanar distance in the diffracting layer changes. The monochromator crystal is exposed to optical radiation with intensity which linearly varies along one of the coordinates of the diffracting layer. Versions of X-ray monochromators for realising the method of generating X-rays are disclosed.
EFFECT: broader functional capabilities when used in high-resolution X-ray optical circuits by providing a wide bandwidth for the monochromator crystal.
18 cl, 4 dwg
SUBSTANCE: method relates to medicine, namely to radiology and can be applied in radiotherapy of oncologic patients. Patient is laid under vertical beam of source of electrons. Energy of beam of electrons is selected. Patient is covered with elastic fabric-equivalent material. After that diaphragms are moved apart for bremsstrahlung at the distance determined by formula L=0.9 × A × DES/DSP, where A is desired size of irradiation, cm; DES - distance electron source-diaphragm, cm; DSP is distance from electron source to patient's skin, cm; 0.9 is numerical coefficient. Irradiation is performed in required dose. After that, patient is moved along their vertical axis for distance A and irradiation is repeated.
EFFECT: method makes it possible to carry out total irradiation of patient's body surface and increases uniformity of irradiation with beam of electrons, as well as reduces time for pre-radiological preparation and irradiation due to application during irradiation of diaphragms for bremsstrahlung field formation.
FIELD: power engineering.
SUBSTANCE: method to generate beams of directional coherent radiation in optical range is carried out with the help of pulse sources of nuclear radiation. Inverse occupation of atoms and molecules of active medium is provided. The active medium is placed in an open resonator. The released energy in the form of a directional coherent beam of optical range photons is taken out beyond the resonator limits via a partially transparent output window of the resonator. The active medium is surrounded with a radioactive medium, or the radioactive medium is placed homogeneously or heterogeneously inside the active medium, the pumping energy of the active medium is increased. The active medium is transferred into a super-radiating condition, from which the active medium, using the initiating start radiation, is transferred into the main (or less excited) condition, by release of the superradiation with intensity that is directly proportional to the squared quantity of excited atoms or molecules. The device of quantum beams generation comprises a quantum generator. Films of uranium-235 (235U) are applied onto inner surfaces of the side walls of pipes, as well as a double-zone pulse nuclear reactor that generates a field of nuclear pumping energy of active Ar-Xe gas mixture (medium). The pulse nuclear reactor is replaced with a power plant of non-nuclear design.
EFFECT: higher efficiency of pumping energy transformation into energy of directional radiation and expanded range of quantum components of radiation beams.
7 cl, 20 dwg
FIELD: power engineering.
SUBSTANCE: device has a stationary vacuumised neutron guide made in the form of a stainless steep pipe, nickel or copper. The device is additionally equipped with a section of a neutron guide made as a flexible polyvinyl chloride tube, the inner wall of which has mirror surface. Values of average roughness of the inner wall of the flexible polyvinyl chloride tube do not exceed the length of the ultracold neutron wave length.
EFFECT: reduced losses of low energy neutrons during transportation, capability of delivering them into hard-to-access areas.
8 cl, 5 dwg, 1 tbl
SUBSTANCE: first, metal template with curved surface of revolution is made to be fitted into glass tubular blank that is sealed and heated to glass thermoplastic deformation temperature, and said template is withdrawn. After cooling template and glass tubular blank, said glass blank is vertically stretched by mechanical force applied to its bottom end. Heating is performed by moving annular heater along template working surface to its taper section.
EFFECT: preset shape with great difference in cross sections, minor roughness.
6 cl, 2 dwg
SUBSTANCE: proposed process includes layer-by-layer cross-linking of photopolymerizing molecules by means of focused optical radiation to produce spatially confined X-ray passages disposed within X-ray absorbing material. To this end X-ray absorbing material is added in advance to photopolymerized material, and collimator space, except for X-ray passages, is cross-linked using photochemical method.
EFFECT: enhanced spatial resolution and convergence of spatially confined X-ray passages into single point; reduced cost of process.
FIELD: radiation shielding and masking systems, those producing illumination effects (advertisement, decorative lights), data display systems.
SUBSTANCE: proposed device that can be used for dissipating electromagnetic radiation, such as light, radio waves, X-rays, as well as for dissipating particle streams is, essentially, multilayer screen some of whose layers are deformable ones. Electric field is built up between two electricity conducting layers due to voltage applied to these layers. In the process conducting layers are split into segments and separate electrodes are brought to respective layers. Voltage applied to separate segments permanently varies with the result that electric field produced is nonuniform and deformable layers are embossed due to nonuniformity of attractive forces between electrodes, this embossed pattern permanently changing its configuration. Radiation (light of different ranges, radio and electromagnetic waves, particle streams) passed through screen or reflected therefrom dissipate due to optical nonuniformity. Kind of dissipation continuously varies due to changes in embossed pattern. Segments of conducting layers can be energized obeying different laws including pseudorandom one.
EFFECT: reduced specific surface power of incident radiation.
4 cl, 2 dwg
FIELD: nuclear physics.
SUBSTANCE: device 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.
EFFECT: higher trustworthiness, higher reliability, higher durability, higher precision.
FIELD: X-ray diffraction and X-ray topography methods for studying the structure and quality control of materials during nondestructive testing.
SUBSTANCE: the invention is intended for X-ray beam shaping, in particular, the synchrotron radiation beam, by means of crystals-monochromators. The device for X-ray beam shaping has two crystals-monochromators in the dispersionless diffraction scheme. It is ensured by the possibility of displacement of one from crystals in the direction of the primary beam with crystal fixing in two discrete positions. Both crystals-monochromators have the possibility of rotation for realization of the successive Bragg diffraction. Device for crystal bending has displacement mechanism, two immovable and two movable cylindrical rods, between of which the end parts of a bent crystal are located. The axes of these parts are displaced one in respect to the other. The immovable rods are leaned against the upper surface of a flat parallel plate near its end faces. The L-shaped brackets are attached to the end faces of plate. The parallel surfaces of the brackets contact with immovable rods. The parallel surfaces of the end faces of the upper joints of L-shaped brackets contact with movable rods. The plate with L-shaped brackets is embraced with crooked shoulders of floating rocker with cylindrical pins, installed on the rocker ends. The pins are leaned against the surfaces of movable rods perpendicularly to them. The displacement mechanism is located between the lower surface of plate and middle point of the rocker.
EFFECT: increasing the energy range of X-ray beam when maintaining its spatial position; improving the uniformity of bending force distribution and homogeneity of crystal deformation.
2 cl, 2 dwg
FIELD: optical instrument engineering.
SUBSTANCE: before conversing parallel laser radiation beam of continuous cross-section to circular-section beam, the central round-shaped part is cut out of parallel laser radiation beam for subsequent delivery to specified circular-section beam convergence point. Device has entrance and exit axions that are optically conjugated. One reflecting conic surface of axion is mounted onto ends of hollow rod connected with other reflecting conic surface of axions through pylons. Cavity of rod is divided by partition provided with nozzles for supplying coolant into mentioned compartments. Reflecting surfaces of axions and partition of rod are made with through axial holes. Diameter of axial hole of reflecting conic surface of axions is commensurable with diameter of spot of focused laser radiation. Laser radiation beams can be focused with higher power of density.
EFFECT: increased power density.
4 cl, 1 dwg
FIELD: roentgen optics; roentgen ray flux reflecting, focusing, and monochromatization.
SUBSTANCE: proposed method for controlling X-ray flux by means of controlled energy actions on control unit incorporating diffraction medium and substrate includes change of substrate and diffraction medium surface geometry and diffractive parameters of this medium by simultaneous action on control-unit substrate and on outer surface of control-unit diffraction medium with heterogeneous energy. X-ray flux control system has X-ray source and control unit incorporating diffraction medium and substrate; in addition, it is provided with diffraction beam angular shift corrector connected to recording chamber; control unit is provided with temperature controller and positioner; substrate has alternating members controlling its geometric parameters which are functionally coupled with physical parameters of members, their geometric parameters, and amount of energy acting upon them. Diffraction medium can be made in the form of crystalline or multilayer periodic structure covered with energy-absorbing coating.
EFFECT: enhanced efficiency of roentgen-ray flux control due to dynamic correction of focal spot shape and size.
3 cl, 1 dwg
FIELD: medical eqipment.
SUBSTANCE: device can be used for rigging digital X-ray diagnostic apparata. Device has for diaphragming working bunch of medical X-ray diagnostic apparatus has depth diaphragm provided with top and lower group of shutters made of material withhigh atomic number, for example, of plumbum. Shutters are made for movement by mechanism connected with electric engine and disposed between entrance and exit holes of depth diaphragm. Case of diaphragm is tightly connected with optical window of X-ray irradiator. Digital photocamera is fixed inside case of depth diaphragm. Photocamera is connected with computer equipped with display and with electric coordinatographic device connected woth electric engine. Digital photcamera is mounted for bringing phot image together with X-ray image. Camera is has two mirrord, one of which mirrors is disposed within area of direct X-ray from X-ray radiator. Shadow image of internal organs is brought into coincidence with image of skin cover of patient within area of rentgenography.
EFFECT: eased scheduling of surgical operation.
FIELD: ultra-violet radiation.
SUBSTANCE: the mirror-monochromator has a multi-layer structure positioned on a supporting structure and including a periodic sequence of two separate layers (A,B) of various materials forming a layer-separator and a layer-absorber with a period having thickness d, Bragg reflection of the second or higher order is used. Mentioned thickness d has a deviation from the nominal value not exceeding 3%. The following relation is satisfied: (nAdA + nBdB)cos(Θ) = m λ/2, where dA and dB - the thicknesses of the respective layers; nA and nB - the actual parts of the complex indices of reflection of materials of layers A and B; m - the integral number equal to the order of Bragg reflection, which is higher than or equal to 2, λ - the wave-length of incident radiation and Θ - the angle of incidence of incident radiation. For relative layer thickness Г=dA/d relation Г<0.8/m is satisfied.
EFFECT: provided production of a multi-layer mirror, which in the range hard ultra-violet radiation has a small width of the reflection curve by the level of a half of the maximum at a high reflection factor in a wide range of the angles of incidence.
6 cl, 1 dwg
FIELD: optical trap matrix control and particle matrix formation.
SUBSTANCE: proposed method and device are implemented by laser and variable-time optical diffraction element enabling dynamic control of optical-trap matrices followed by controlling particle matrices and also using plurality of optical traps to provide for handling single objects.
EFFECT: improved method and system for producing plurality of optical traps.
30 cl, 10 dwg
FIELD: radiation engineering; devices for controlling particle flux or electromagnetic radiation using collimator for the purpose.
SUBSTANCE: proposed radiation head has radiation source holder installed in fixed housing made of absorbing material with biological-shield wicket gate joined with its cylindrical sliding surface and labyrinth collimating surface which form ball in closed position; wicket gate pivot is located in center of cylindrical surface of housing. In addition, set of filters separately mounted in stepped spline guides of housing is attached radially relative to common pivot, butt-ends of filters being congruent to housing collimating channel surface; holder is provided with blind pocket in butt-end opposite to source which has through slit to receive telescopic lock damper; the latter is mounted on rod whose spring-loaded flange is loosely mounted inside supporting grip; each filter is separately secured on double-arm positioning lever.
EFFECT: enlarged capabilities of dosing radiation power, enhanced radiation safety in head servicing and storage.
3 cl, 4 dwg