Method of realizing of neutron-catch therapy of oncological diseases

FIELD: nuclear medicine.

SUBSTANCE: method of realizing of neutron-catch therapy is based upon introduction of medicinal preparation into damaged organ or tissue of human body. Preparation has isotope with high cross-section of absorption of neutrons. Then damaged organ or tissue is irradiated by neutrons of nuclear reactor. Irradiation is performed with ultra-cold neutrons with energy of 10-7 eV and higher, which neutrons are released from cryogenic converter of neutrons of nuclear reactor and are delivered to damaged organ or tissue along vacuum neutron-guide, which neutron-guide has end part to be made in form of flexible catheter. Dosage loads are reduced.

EFFECT: minimized traumatism of healthy tissues of patient.

4 cl, 1 dwg, 1 tbl

 

The technical field to which the invention relates.

The invention relates to nuclear medicine, radiation therapy and can be used to implement neutron capture therapy, has found application in the treatment of cancer.

Prior art

In medical practice it is known that the available methods of cancer treatment is not effective enough - about 50% of cancer patients die from the disease. Mortality from cancer ranks second after cardiovascular diseases. Treatment of patients with malignant tumors refers to the priority of the state and scientific tasks in all developed countries of the world.

Today, for the treatment of cancer using three main methods of treatment: surgery, radiation therapy and chemotherapy. Among these methods, radiation therapy alone or in combination with other methods used in 40-75% of all cases of cancer, and there are trends of increasing this role in the near future.

One of the promising directions of radiation therapy is neutron therapy. It is preferable to other methods of radiation therapy in cases of locally advanced tumours of the head and neck, salivary glands, breast cancer. Advantages Nate is Onna therapy as demonstrated by recovery of primary tumor, and to overcome metastasis of malignant tumors. The positive effect is achieved not only by radical radiation exposure, but also due to the transition of a tumor in an operable form with subsequent surgical intervention.

Currently known neutron therapy, implemented in two versions - neutron-capture therapy (NRT) and fast neutron therapy (TBN). Especially promising neutron-capture therapy, based on the absorption of neutrons stable boron isotope10In (boron neutron capture therapy) or other element with a large capture cross section for neutrons and releasing considerable energy to the reaction products. The effectiveness of NRT data demonstrate the treatment of brain tumors of various etiologies: 35% of patients were alive five years after neutron therapy, while traditional treatment increases the life expectancy of only 8-10 months. Five-year survival of patients with mnogomorfnaya glio up to 50% without significant mental and physical degradation, while the best medical treatment gives only about 3% of cases five-year survival with significant mental degradation [Vphoto, Knezev, Whichshow and other Development of radiation technologies in the treatment of malignant tumors based on the neutron-to is based therapy. // Engineering physics No. 1, 2000, p.52-55].

The essence of the method of neutron capture therapy consists in the following. In the first stage, the tumor is injected drug containing chemical elements with a large capture cross section of thermal neutrons, such as boron, gadolinium, etc. Then the tumor is irradiated by thermal neutrons. When it absorbs a neutron, for example, boron isotope10In the reaction10In(n, α)7Li is formed α-particle and ion7Li, mileage which in biological tissue is about 10 μm. However, they emit energy of 2.3 MeV in the range of cells that contain a nucleus10In that leads to its destruction. This ensures the selective destruction of cancer cells while preserving normal tissue intact.

One of the most important requirements when conducting NRT is the reduction of radiation dose to the healthy parts of the patient's body and especially on the surface of the fabric. The focus of the neutron beam, filtering the background γ-rays and fast neutrons allows to minimize radiation doses. To the greatest degree requirements reduce the radiation dose γ-rays and fast neutrons satisfy tangent horizontal experimental channels of research reactors. The peculiarity of such channels is h what about their axis does not pass through the active zone of the reactor the source of fast neutrons and γ-quanta, which excludes the possibility of falling into the channel unscattered radiation. The admixture of fast neutrons and γ-radiation output from the tangent of the channel is less than the radial channel. The number of thermal neutrons must remain the same, if luminous surfaces are in identical conditions as the neutron flux in the reflector isotropic.

As a prototype of the selected reactor method for making NRT using beams of thermal neutrons derived from the active zone of the nuclear reactor, collimated and transported to the place of radiation therapy (Kulakov, VN, Khokhlov, V.F., Zaitsev, PHD, Portnow A.A. Way neutron capture therapy of malignant tumors and device for its implementation. RF patent 2141860, 06.02.1998]. In this way the biological object (a malignant tumor) to introduce boron - and/or gadoliniumbased connection in the extended form, and then fail to tumors derived from reactor neutrons. Field irradiation optimize energy and intensity using a system of filters and collimators.

The disadvantages of this method is unfavorable spatial distribution of neutrons in the body of the patient with the highest absorbed dose of neutrons on the surface of the body (the skin), rapid decrease in dose with depth is th - already at a depth of ˜2 cm neutron flux decreases in 2 times [Knezev, Art, Vassikin and other neutron capture therapy with thermal neutrons on the IRT MEPhI // Atomic energy, v.91, no 4, October 2001, str-314] and the background of fast neutrons and a companion γ-radiation, leading to radiation lesion of the normal tissues of the patient. This limits the use of the method only superficial or shallow-lying tumors. In addition, it is necessary to apply special measures to suppress the background of fast neutrons and a companion γ-radiation.

Disclosure of inventions

The task to be solved by the invention is to improve the implementation of neutron-capture therapy of malignant tumors.

The technical challenge is to meet the requirements of minimizing damage to healthy tissues of the patient by reducing the dose loads from associated γ-radiation and fast neutrons on the healthy parts of the body, the possibility of transport of the neutron beam to the deep lying tumors and effective impact on tumors of small size.

The problem is solved by the fact that the method of implementation of the neutron-capture therapy of cancer involves the introduction into the affected organ or tissue of a person's medical p is eparate, containing an isotope with a high cross section for the absorption of neutrons, and subsequent exposure of the affected organ or tissue by neutron nuclear reactor and irradiation are of ultracold neutrons with energies below 10-7eV, which is removed from the cryogenic Converter neutron nuclear reactor and deliver to the affected organ or tissue by vacuum neutron guide, the end part of which is made in the form of a flexible catheter.

In the private version of ultracold neutrons delivered to the affected organ or tissue, for example, the esophagus, oral cavity, bronchi, urinary tract, rectum.

In another private version of ultracold neutrons delivered to the affected organ or tissue through a flexible neutron guide-catheter, made for example of copper, or Nickel, or stainless steel.

In another private option as an isotope with a high absorption cross section of neutrons using lithium-6, or boron-10 or gadolinium-157.

Ultracold neutrons (UCN) have a speed of <10 m/s and a wavelength of from several hundreds to thousands of angstroms. One of the features of UCN is their ability to experience total reflection from the surface of condensed matter at all angles of incidence. The existence of the phenomenon of reflection of neutrons is very low energies and its ability DL is positive retention of neutrons in special containers was first noted in [for theoretical physics // JETP, 1959, T.36, str]. The phenomenon of total reflection of UCN, the possibility of long-term retention in closed volumes and transportation in the guide have been demonstrated in numerous experiments [III, Wpprotecto. Neutron physics. - M.: Energoatomizdat, 1997, s-342].

Time UCN storage in special containers is determined by the lifetime of the free neutron to βdecay and loss as a result of inelastic scattering or capture in collisions with the walls of the storage volume. Threshold energy for total reflection of neutrons from the surface at all angles of incidence is determined by the expression:

,

where the first member of the nuclear and the second magnetic scattering;

μ is the magnetic moment of the neutron;

ρ - density of nuclei;

b is the length of the coherent scattering;

A - mass number;

B - magnetic induction;

(±) for neutron spin parallel and antiparallel directions of the Century

When b>0 neutron originating from vacuum environment, meets positive barrier height of U. For most nuclei (Be, C, Mg, Fe, Cu, Zn, Pb, etc.) b>0 and only for some types of nuclei (Li, Mn, Ti, V) b<0. If E<U, the neutron is reflected and does not pass the boundaries. For almost all substances Eg˜10-7eV. U-value and critical speeds for different substances shown is in the table.

Table
SubstanceU(10-7eV)Vgm/cSubstanceU(10-7eV)Vgm/c
H2O-0,146-Ti-0,500-
Polyethylene-0,070-Mn-0,680-
Be2,5006,90Fe3,5008,20
C (graphite)1,750of 5.83Gr. steel1,8206,05
Mg0,5953,37Cu1,7205,70
Al0,5413,22Co1,7405,76

Traditionally, the problem of producing ultracold neutrons is solved by extracting the low-energy tail of the Maxwell distribution of thermal neutrons at the exit of the moderator of a nuclear reactor. This uses the ability of UCN reflected from the surfaces of materials such neutrons are "locked" in the closed storage vessel, where they are routed from nuclear re ctor. However, because the share of very cold neutrons in thermal spectrum reactor is negligible, then "exit" ultracold neutrons in this approach is very limited.

There is another possibility of obtaining ultracold neutrons - cooling of the neutron after exiting the moderator of the reactor while passing through the cryogenic Converter (Converter) with low-temperature retarder, for example, superfluid helium, solid or liquid deuterium, liquid hydrogen. This is quite an efficient transfer of energy from neutron reactor the phonons (the quasiparticle representing the quantum of elastic oscillations of the environment), which significantly increases the proportion ultrahealthy neutrons. The Converter is located outside of the neutron reflector and the biological shield of the reactor to reduce thermal effects of radiation on the low-temperature moderator.

In the first experiments on the extraction of UCN from the reactor and the retention capacity of the neutron flux density was ˜0.1 g/(cm2·). Currently, the values of the flux density of UCN by five orders of magnitude higher. In the reactor of the Institute. M.laue and Plongeon in Grenoble flows UCN reach values of more than 104n/(cm2·). It is expected that by improving the technology of removing bundles of threads UCN will increase at least n is two or three orders of magnitude, to the level of 106-107n/(cm2· (C) [III, Wpprotecto. Neutron physics. - M.: Energoatomizdat, 1997, s]. Such values of density flows allow us to consider the possibility of practical use of UCN in various fields of science and technology, including for the needs of nuclear medicine.

It is believed that for the clinical application of NCT required flux of thermal neutrons density ˜10 n/(cm2· (C), and the admixture of fast neutrons should not exceed 1%. The degree of damage of tumor cells with neutron therapy Ntcan be estimated using the simple expression [Knezev, Art, Vassikin and other neutron capture therapy with thermal neutrons on the IRT MEPhI // Atomic energy, v.91, no 4, October 2001, str-314]:

where ρ10- concentration10In the tumor;

ϕ is the density of thermal neutron flux at the location of the tumor;

t - duration of exposure

σ - capture cross section of thermal neutrons by the nucleus10Century

At concentrations10In tumors of 30 µg/g and the capture cross section of 3.84-103barn [Radiative capture of neutrons. The Handbook. M.: Energoatomizdat, 1986] 1 hour exposure in each milliliter of its volume in the neutron flux of 109n/(cm2· (C) born more than 2-1010α-parts and recoil 7Li. Because in 1 ml of melanoma contains about 109cancer cells [Knezev, Art, Vaselkin and other neutron capture therapy with thermal neutrons at the reactor IRT MEPhI // Atomic energy, v.91, no 4, October 2001], each cell melanoma accounts for about 20 pairs α-particles and nuclei7Li. For the destruction of cancer cells with just a few α-particles. [P.M.Macklis, Y.J.Lin, B.Beresford et al. Cellular kinetics, dosimetry and radiobiology of alpha-particle immunotherapy: induction ofapoptosis. Radiat. Res. 1992. V.130. p.220-226].

As follows from expression (1), the degree of destruction of tumor cells depends not only on the magnitude of the neutron flux, but the cross-section of neutron capture, which for UCN is significantly higher than for thermal neutrons.

The capture cross section of ultracold neutrons for a 1/v absorber σandUCNcan be obtained by using the value of the cross section for neutrons arbitrary speed σand(E0=CT) using the following expression [III, Wpprotecto. Neutron physics. - M.: Energoatomizdat, 1997, s]:

σaUCNa(E0=CT)/(vkT/vUCN)

where vkT- the speed of the neutrons at the temperature T;

vUCN- the speed of ultracold neutrons.

In the case of the so-called westcotts approximation using the capture cross section σand(E0=CT) for T=293,6°K, which then corresponds to the speed of the neutron v 0=2200 m/s Then the capture rate for UCN 1/v absorber will be equal to:

N=ϕUCN·[σa(v0)(v0/vUCN)]

Because the rate of UCN ˜8 m/s [III, Wpprotecto. Neutron physics. - M.: Energoatomizdat, 1997, s], then the value of Ntfor UCN increases compared to neutrons of thermal energies 275 times.

The depth of penetration α-particles in biological tissue varies from 30 to 80 μm, which corresponds to several cell diameters. The density of ionization reaches -100 Kev/μm, so that the distance between two successive acts of interaction is comparable with the distance between the two strands of the DNA helix. Therefore, the probability to provide double the gap of the spiral with one α-particles is high enough, that automatically means high therapeutic efficacy.

Therapeutic effect of UCN capture can be estimated based on the power of the absorbed dose in the tumor [RF Patent 2212260 Way of planning neutron capture therapy. The authors Sealants, Sundarji, Wagrowska etc.]:

P=f·and(Cswelled.NA/M)·σaUCNE·K, [cGy/s]

where f is the flux density of UCN, n/(cm2·);

Withswelled.- concentration10In tumors, g/g tissue;

NA- the number of Avogadro;

M - molecular mass hee the practical element with a high capture cross section of thermal neutrons;

σandUCN- capture cross section of ultracold neutron, cm2;

E - the energy from the reaction products, MeV;

K=1,6·10-8cGy·g/MeV - coefficient of dimensional consistency.

At concentrations10In tumors of 30 µg/g, which is equivalent to≈2·1018nuclei10In/g, the capture cross section ≈106barn(10-18cm2) and the flux density of UCN ≈106n/(cm2·C)the power absorbed in tumor radiation dose R will amount to 4.2·10-2Gr/min At 2-hour exposure absorbed dose will exceed 5 Grams.

The dose necessary to kill cancer cells depends on the number of viable or count of clonogenic cells. So, for 1012cells necessary dose of 60 Gy to 108cells 40 Gy to 104cells 20 G and 100 cells, a dose of 10 Gy [Gerd-Jurgen Beyer alpha-emitting radionuclides - production and application. // The isotopes. Properties. The receipt. Application. Vol.2, M.: Fizmatlit, 2005]. However, it should be borne in mind that the allowable dose to the bone marrow is 1-5 GRS, for blood - 1-5 Gr for cardiovascular system - 10-20 Gy and for the whole body - 2 Gr. Lethal dose for subclinical tumor entities from 104cells - 20 Gr. To limit systemic dose on a body to Gr 2, you must ensure that the ratio of the dose distribution naked the narrow tumor/tissue of at least 10:1. For 100 cancer cells circulating in the blood, you need 10 G and, therefore, need to provide a ratio of 5:1. It is believed that the dose of 5 Gy is approaching the optimal level of radiation exposure for a malignant tumor.

Thus, the use of a beam of ultracold neutrons with a flux density of 106n/(cm2· (C) and the exposure time is not more than 2 hours provides the necessary therapeutic effect in the treatment of cancer.

The implementation of the invention

As the neutron source can be used in a nuclear reactor neutron flux in the core ˜1014n/(cm2·).

Neutrons from the reactor core is transported in the low-temperature Converter, representing cryogenic cryostat filled with liquid superfluid helium. The wall of the Converter is made of a material that provides a full reflection of UCN on the border.

After slowing down in the low-temperature Converter ultracold neutrons through a thin transparent window with b<0 are served in the vacuum neutron guide, which is transported to the experimental hall, where they conduct experiments or medical procedure for NRT. Vacuum neutron guide support to reduce the loss of neutrons in the process of diffusion. As the material of the walls are usually used honey is, Nickel or stainless steel.

The distribution of UCN in the neutron guide is similar to the flow of rarefied gas through the pipes and is characterized by the diffusion lengthwhere D is the diffusion coefficient, determined by the degree of specularity of the surface; T is the lifetime of a neutron in the neutron guide with respect to all processes: the absorption of neutrons walls and heated in a collision with the walls. Some UCN is lost in collisions with nuclei of the residual gas atoms and collisions with the walls of the neutron guide. The intensity UCN depending on the distance (1) to the Converter is given well-known exponential law exp(-1/Lc). For electropolished of the guide diameter ˜10 cm experimental values of Lcreach ≈10 m

Neutrons with energy E<Fgwhen moving inside a neutron guide will be repeatedly reflected from the walls, and the trajectory of the neutrons will follow the curves of the neutron guide. Even rotate 180° does not increase the "resistance" of the neutron guide. Neutrons with energy E>Fgexit of the neutron guide or just behind the Converter after the first collision with the wall (if the conditions of total external reflection are not met), or in the bend of the neutron guide after several reflections of them on the straight parts. Vero is tnost mirror reflection of UCN is of the order of 0.8 to 0.9.

The end part of the neutron guide is made in the form of a flexible catheters bellows - type corrugated thin-walled metal tube. At the end of the catheter is a thin, transparent window with b<0, through which ultracold neutrons come into a malignant tumor.

An example of the method

Method for making a neutron-capture therapy of cancer implement the system shown in the drawing. The installation consists of the reactor core 1, the neutron reflector 2, the horizontal channel 3, cryogenic Converter 4 - UCN source, vacuum neutron guide 5 for delivery of ultracold neutrons for medical procedures on neutron capture therapy, flexible neutron guide-catheter 6 for the supply of the UCN directly to the affected organ or human tissue.

As the primary neutron source selected experimental research reactor IR-8 thermal capacity of 8 MeV. The maximum neutron flux in the reactor core reaches 2·1014n/(cm2·).

Neutrons from the reactor core 1 and the tangent to the horizontal channel 3 with a diameter of 100 mm, made of aluminium, served in the low-temperature Converter 4, filled with superfluid liquid helium. The wall of the Converter is made of isoto is and Nickel Ni-58, providing a full reflection of UCN at the border. On the outside of the Converter is surrounded by thermal and radiation protection.

In the scattering on nuclei neutron superfluid helium loses almost all the energy. Neutrons with energies ˜10-7eV through a thin transparent window with b<0 are served in the vacuum neutron guide 5, which is transported to the experimental hall, where they conduct experiments or medical procedure for NRT. The residual pressure in the neutron guide is maintained at the level not higher than 1.3 to 10-2PA. As the material of the wall of the neutron guide use Nickel. The inner surface of the neutron guide is covered with a hydrogen-free oil Fomblin (F3CCF2OCF2CF5)nto reduce losses of UCN on the walls.

If necessary, the neutron beam can be blocked using neutron gates, representing opaque to ultra-cold neutrons screen made of Nickel.

The end part of the neutron guide is made in the form of a flexible neutron guide-catheter 6 bellows - type corrugated thin-walled metal tube. The catheter with a diameter of 10-15 mm ultracold neutrons screen delivered directly to the diseased organ in the esophagus, oral cavity, bronchi, urinary tract, rectum, or other way. Neutron flux at the output of the C of the catheter reaches values ˜ 106n/(cm2· (C)that provides the necessary doses for operations on neutron capture therapy.

The proposed method of implementation of invasive neutron capture therapy of malignant tumors allows for the use of beams of ultracold neutrons to minimize damage to healthy tissue of the patient to be transported neutron beam to deep-seated tumors, effectively influence tumor of the small size.

1. Method for making a neutron-capture therapy of cancer, comprising introducing into the affected organ or tissue of a person medical preparation containing an isotope with a high absorption cross section for neutrons and subsequent exposure of the affected organ or tissue by neutron nuclear reactor, characterized in that the irradiation leads ultracold neutrons with energies below 10-7eV, which is removed from the cryogenic Converter neutron nuclear reactor and deliver to the affected organ or tissue by vacuum neutron guide, the end part of which is made in the form of a flexible catheter.

2. The method according to claim 1, characterized in that ultracold neutrons delivered to the affected organ or tissue, for example, the esophagus, oral cavity, bronchi, urinary tract, rectum.

3. The method according to claim 1, the tives such as those the flexibility of the catheter is performed, for example, of copper, or Nickel, or stainless steel.

4. The method according to claim 1, characterized in that as an isotope with a high absorption cross section of neutrons using lithium - 6, or boron - 10 or gadolinium - 157.



 

Same patents:

FIELD: nanotechnology, namely, devices, ensuring movement of object in a plane by two coordinates, possible use for moving samples, sample carriers, probe carriers and other elements in scanning probe microscopy.

SUBSTANCE: two-coordinate micro-positioner contains base, on which first motor is held for first coordinate, engaged by means of first lever and first flexible carrier to first moving carriage, while first lever is mounted on the base with usage of first flexible joint, and first moving carriage is mounted on the base by means of first flexible guides. On the first mobile carriage, second mobile carriage is positioned by means of second flexible guides. Second motor for second coordinate is present, with second lever, containing second flexible joint, and second flexible carrier. Second motor is held on base and engaged by second lever by means of second flexible carrier to second mobile carriage. Second lever is mounted on the base with usage of second flexible joint. Between the base and first and second flexible joints, inserts are positioned with temperature expansion coefficient different from temperature coefficients of the base, first and second mobile carriages, first and second lever, first and second flexible guides and motors. First and second position measuring strain sensors may be connected to first and second motors for first and second coordinates.

EFFECT: increased speed and precision of measurements.

9 cl, 8 dwg

FIELD: methods and devices for treatment of oncology patients using sources of ionizing radiation, namely, technology of pre-irradiation preparation and irradiation during intracavitary and interstitial radiotherapy.

SUBSTANCE: method for pre-irradiation preparation and irradiation includes positioning the patient on treatment-diagnostics table, inserting into cavity to be irradiated of hollow applicators with imitators of ionizing radiation sources, controlling position thereof relatively to target being irradiated with usage of x-ray television device, building of dosimetric plane and irradiation, while applicators inserted into cavity being irradiated are connected to treatment-diagnostics table, x-ray radiography is performed with output of image onto monitor of viewing station of x-ray television device, image via the interface is transported into planning system, dosimetric plane of irradiation is computed, which is then exported into system for controlling device and irradiation procedure is performed. Treatment-diagnostics table has frame, two supporting posts with overhung table top mounted on them, consisting of a pelvic-dorsal and two extending leg sections, connected to pelvic-dorsal section by means of twin joints. For connection of applicator table is provided with mounting pillar.

EFFECT: possible irradiation directly near apparatus without moving the patient during x-ray control of position of applicators and, therefore, increased quality of radiotherapy and therapeutic efficiency, decreased duration of pre-irradiation preparation.

2 cl, 3 dwg

FIELD: physics of reactor radiation in various materials.

SUBSTANCE: proposed device is made in the form of truncated cone whose smaller base is oriented to object and has set of water-containing neutron moderator plates alternating with converter plates made of material absorbing thermal neutrons in radiation capture reaction. Diameters of cone larger and smaller bases are chosen so as to ensure shading of entire object under test and its middle part from direct rays of reactor, respectively. Cone height is chosen so as to ensure desired ratio of neutron attenuation in middle part of object.

EFFECT: reduced nonuniformity of neutron distribution lengthwise of object under test, enhanced gamma-ray dose contribution in object radiation loading field.

1 cl, 4 dwg

FIELD: irradiating devices adapted to relative displacement of radiation source and part being irradiated.

SUBSTANCE: proposed device that has electron accelerator with slit-type outlet window and castor-mounted modules is provided in addition with paired modules whose castors are of different diameters and are installed on axles of modules in increasing or decreasing order of their diameters, order of castors installation on axles within each pair of modules being similar; modules of each pair are disposed either side of outlet window against one another and their axes are parallel and are crossing plane of outlet window disposition, and also they cross or are intersected with axes of modules of one or more pairs. Where module castors are of different diameter, these diameters vary in arithmetical progression whose difference equals double pitch of their disposition on module axle multiplied by tan α, where α is angle between module axle carrying castors and plane of outlet window disposition.

EFFECT: improved quality of irradiated parts, such as cables, due to their uniform irradiation.

2 cl, 6 dwg

FIELD: radiation engineering and technology; physicochemical processes for treatment of materials with dosed ionizing rays to impart new useful properties to them.

SUBSTANCE: proposed method for radiation treatment of parts and materials with hard rays of fission products accumulated in closed loop of circulating-fuel nuclear reactors involves use of ultrashort-living gaseous products of fission accumulated in liquid-fuel homogeneous reactor core which are removed with gas flow from fuel solution and conveyed over closed loop to radiation chamber accommodating parts and materials to be irradiated wherein high-strength field of gamma-rays is built up due to disintegration of ultrashort-living products of fusion; then gas flow depleted with respect to fusion products as result of their radioactive disintegration is returned to reactor core.

EFFECT: enhanced operating safety at desired gamma-ray power level; enlarged functional capabilities.

3 cl, 1 dwg

FIELD: physics.

SUBSTANCE: device is a module, containing capacitor, connected to pulse gas triode, commutating discharge of capacitor through cable line onto load block (current collector) and discharge chamber mounted therein, wherein a charge of plasma focus type is formed; discharge device; gas-filled triode heat source, triode launch system, pulse generator, launching the triode launch system, control system for generator and capacitor; diagnostic and recording hardware, cable line is made of coaxial wires of even length, evenly distributed along circle of current-conducting flanges of triode and load block; discharge chamber with load block can move in vertical and horizontal directions; electric isolation of anode space of load block is made in form of multilayer inserts packet of dielectric material; capacitor and load block are galvanically isolated from mounting plate; anode and cathode of load block are galvanically interconnected through resistors block; cathode of load block is galvanically connected to mass of mounting plate; device elements are compactly mounted and held by force elements on mounting plate.

EFFECT: higher durability, higher efficiency.

2 dwg

FIELD: neutron transmutation doping of industrially produced silicon in fast reactors.

SUBSTANCE: proposed device primarily designed for type RBMK reactors has through flow path with bellows compensator and external shell fixed to the latter and made in the form of sleeve, build-up path, and head, all joined in tandem; sleeve is mounted through its top part on supporting shoulder of through flow path in bore of graphite blocks of neutron reflector; device is also provided with internal tube mounted in a spaced relation inside external shell, as well as with cooling liquid inlet and outlet units forming cooling system together with external shell and internal tube; ionizing radiation shielding means are installed inside and outside of external shell; device is also provided with telescopic hanger of irradiation container disposed within internal tube and joined to bottom section of hanger; the latter is provided with vertical displacement and rotation actuator disposed in upper part of external shell; sleeve condition checkup system is placed outside of external shell.

EFFECT: improved properties of doped silicon, enhanced doping uniformity, reduced trouble probability.

4 cl, 7 dwg

FIELD: physics of charged particle beams, roentgen and deceleration radiation.

SUBSTANCE: proposed device that can be used in developing systems for Customs inspections of large-size goods and installations for X-ray control of thick-wall metal objects has electron beam injector, contact-type linear electron accelerator, conversion target, local radiation shield with radiation collimator, and power supply. Electron injector has thermionic cathode with mask made in the form of metal screen, and in addition it may have current-carrying coil for building up magnetic field around cathode. Linear electron accelerator has resonator made in the form of biperiodic chain of coupled cells where length of accelerating cells increases from accelerator origin to its end.

EFFECT: enhanced penetrating ability and power of source-generated radiation.

2 cl, 4 dwg

The target node // 2243610
The invention relates to the field of physics and technology of particle accelerators, namely, devices for installation and replacement of solid targets in experiments in high energy physics to produce beams of secondary radiation

FIELD: technical physics, in particular, accelerators of light ions, possible use as generator of neutrons.

SUBSTANCE: accelerator of ions with magnetic isolation contains vacuumized cylindrical cover, made of dielectric material, provided with vacuum pump, magnetic coils positioned outside the cover, connected to impulse electric power source and creating axial magnetic field, anode and cathode, made in form of coaxial tubes, connected to high voltage source. Accelerator is provided with gas tank, adjustable by gas inlet valve and means for controlling gas pressure, accelerating inducers and additional magnetic coils, which are positioned on external surface of vacuum cover between inducers and are connected to impulse electric power sources. Device is also provided with inverse coaxial magnetrons with smooth anodes, each magnetron is connected to accelerator space via through slit, made in cathode of magnetron and lying in plane, passing through appropriate cover diameter in parallel to its generating line. Anode tube is made in form of part of cover, on vacuum surface of which axially-symmetrically and with provision of electric contact by their cathodes magnetrons are mounted, while their anodes are connected to impulse electric power sources.

EFFECT: decreased instability of ion current.

1 cl, 2 dwg

Neutron tube // 2287197

FIELD: engineering physics; neutron production for various applications.

SUBSTANCE: proposed neutron tube has body accommodating three-electrode controlled ion source whose anode and cathode are saturated with hydrogen ions, as well as insulating target and gas absorbers. Target is made in the form of identical three-electrode controlled ion source disposed within tube body against first ion source for simultaneous supply of negative and positive voltage pulses of same amplitude to both ion sources in turn.

EFFECT: enhanced service life of tube affording rated neutron yield.

1 cl, 1 dwg

FIELD: nuclear physics and applied industries.

SUBSTANCE: neutron production process depending on interaction between accelerated deuterium ions and tritium nuclei includes bombardment of composite target under operating conditions of generation by deuterium ions accelerated to energy E when deuterium ion path in target is greater than total thickness of H1 + H2 + H3 layers, with neutron flux level being continuously measured; as soon as flux reduces below minimal level, deuterium supply to ion source is shut off, tritium is fed to the latter, and target is irradiated by tritium ions at accelerating voltage equal to 0.5 + 0.05 of deuterium ion accelerating voltage level under regeneration operating conditions. Tritium is periodically supplied to ion source at intervals T = (0.1 + 0.01)Td(Id/It), where Td is target operating time up to neutron flux level reduction from rated value to minimal level; Id is mean current of deuterium ions under operating conditions; It is mean current of tritium ions for target stuffing; then tritium supply to ion source is ceased and neutrons are generated by feeding deuterium thereto; neutron flux level is measured until its increment between two sequential measurements reduces to value equal to measurement error, whereupon neutrons are generated under operating conditions.

EFFECT: ability of producing maximal neutron fluxes using tritium target at its maximal life.

1 cl

FIELD: neutron entrapping therapy.

SUBSTANCE: proposed method includes irradiation of stream of solid active-material rarefied particles moved perpendicular to mentioned beam by accelerated charged particles, such as protons, to conduct neutron-producing reaction in mentioned particles. Active material particles can be moved using gravitational forces or pressure difference between volumes of active-material particles being fed and received to form particle suspension in rarefied light gas. Size, volume concentration, and thickness of active particle stream are chosen so as to optimize nuclear reaction conditions. Heat energy released in the process is uniformly distributed throughout entire volume of active particle stream in working zone thereby simplifying target cooling. Neutron-producing assemblies implementing this method are described in invention specification.

EFFECT: facilitated procedure, reduced cost of neutron production for medicine.

17 cl, 10 dwg

FIELD: neutron-entrapping therapy.

SUBSTANCE: proposed neutron-producing target assembly has target with active material which is essentially thin-walled shell of revolution made in the form of sphere or cylinder and disposed within casing filled with circulating cooling medium. Charged particles arrive at target from accelerator outlet through inlet window whose dimensions are much lower than diameter of thin-walled shell. Neutrons being produced escape cavity filled with cooling medium through collimating outlet window. Assembly is provided with means for setting target in rotary motion and means preventing cooling medium ingress in inlet window space. Target in one of assembly alternatives is set in motion by means of drive. In other alternative target made in the form of sphere resides in cooling liquid within casing in suspended condition and is set in rotary motion by means of cooling medium flow.

EFFECT: simplified design and reduced size of apparatuses for conducting neutron therapy directly in cancer clinics and centers.

13 cl, 4 dwg

Neutron generator // 2273118

FIELD: nuclear engineering, in particular, engineering of neutron generators, possible use, for example, in neutron tubes for logging research.

SUBSTANCE: neutron generator additionally includes sprayer of hydrogen-active metal onto target. Metal is applied during breaks in generator operation, being saturated with deuterium and tritium from gas located within the tube. Target with diameter D is positioned in plane of target base. Sprayer has frame made of vacuum dielectric material, wherein grooves are made, where with possible reciprocal movement in plane perpendicular to pipe ignition electrodes are positioned. Mobility of ignition electrodes allows by means of corrugated pipes without disruption of vacuum to alter gap between them and sprayed electrode from outside the pipe, to achieve guaranteed disruption of gap and generation of arc under effect from voltage of sprayer electric power. Sprayed electrode is made in form of a truncated cone provided with aperture. Sprayer also has protective metallic cover in form of hollow truncated cone, top of which is positioned in target hollow. Selection of angle between generatrices of cover in cross-section, passing through its axis, being equal to 2,2 arctg(0,5(Dk-D)/H), where Dk - internal diameter of cover in cross-section coinciding with plane of top of sprayed electrode cone, D - diameter of substrate, and H - distance from this plane to target plane.

EFFECT: increased lifetime of target, possible increasing of neutron output of generator by increasing flow of deuterons bombarding the target.

1 cl, 3 dwg

Vacuum neutron tube // 2267181

FIELD: neutron engineering; production of devices for generation of a fast neutrons stream.

SUBSTANCE: the invention is pertaining to production of devices for generation of a fast neutrons stream, in particular, to production of vacuum neutron tubes. The invention presents the vacuum neutron tube, which has been made in the form of a hermetic body with located inside it a source of ions representing a system "an electron projector - an emitting ions anode" and a neutron-forming target. The internal space is divided into two sealed volumes by a diaphragm with a hole, in which there is a hermetically fixed anode facing the target. In one of the volumes there is a cathode of the electron gun, and in the other - the target is placed. The technical result of the invention is simplification of the vacuum neutron tube design, increased its effectiveness due to an increased emissive capacity of the cathode.

EFFECT: the invention ensures simplification of the vacuum neutron tube design, its increased effectiveness and emissive capacity of the cathode.

8 cl, 1 dwg

The invention relates to the field of nuclear engineering

The invention relates to the field of devices for GIW, in particular downhole neutron generators

Vacuum neutron tube // 2228554
The invention relates to a device for generating a pulsed fast neutron flux

FIELD: production of radioactive isotopes.

SUBSTANCE: proposed method for producing nickel-63 radioactive isotope from target within reactor includes production of nickel-62 enriched nickel target, irradiation of the latter in reactor, and enrichment of irradiated product with nickel-63, nickel-64 content in nickel-62 enriched target being not over 2%; in the course of product enrichment with nickel-63 nickel-64 isotope is extracted from irradiated product.

EFFECT: enlarged scale of production.

1 cl, 2 tbl

Up!