BR102013033623B1 - ISOTOPIC TRANSMUTER FUSER LINEAR CELL - Google Patents

Abstract

isotopic transmutator linear fuser cell. The present invention refers to a linear isotopic transmutator fuser cell (clfti), characterized by constituting a compact nuclide activating device, where deuterium (d) or tritium (t) ions are accelerated and transported along the axial axis of the cell , consisting of a cylindrical plasma chamber (38) fed by radio frequency antenna (45) and (46); having, in sequence, a set of electrodes, namely: plasma (31), suppressor (32), grounded (33), confinement (34), and target (35), which accelerated ions d or t against the target (34) coated with deposited metal hydrides (34), where dd, dt or tt reactions generate neutrons; a cooling system and insulator of the target electrode, by refrigerant fluid (48); a neutronic moderator in a cylindrical receptacle (40) of adjustable length; one or more sample receptacles (37) axially inserted into the moderator; the cell being covered by a neutron reflector (42) and shielding (41) and (43). clfti is intended to generate radioisotopes with short or long half-life, to produce materials and substances of interest in medical diagnosis and therapy; to reduce the stability of long half-life radionuclides, favoring the burning of radioactive waste; to eliminate unwanted radioactive sources; to produce nuclear fuel from fissile elements; to be useful in chemical concentration analysis by activation of ready ranges.

Description

[001] The present invention refers to an Isotopic Transmuting Linear Fusing Cell (CLFTI), characterized by constituting a compact nuclide activator device, whose deuterium ions (d) are accelerated and transported along the axial axis of the cell, this consisting of a cylindrical plasma chamber (38) which can be powered by an external (45) or internal (46) radio frequency antenna; having, in sequence, a set of cylindrical electrodes referring to: plasma (31), suppressor (32), grounded (33), confinement (34), and target (35), which accelerated deuterium ions (d) or tritium (t) against the target represented by a face of a metallic cylinder (35) covered with deposited metallic hydrides (35) where dd, dt or tt fusion reactions occur, generating neutrons; a cylindrical target electrode refrigeration and insulator system, with refrigerant fluid (48), a neutron moderator in a cylindrical moderator receptacle (40) of cylindrical length adjustable to the energy level of the transmutation neutron beam; one or more sample positioning receptacles (37) to be transmuted axially inserted into the moderator; and covered by a neutron reflector (41), and shielding (42) and (43). CLFTI has the purpose of activating nuclides through neutron transmutations, so that they can generate radioisotopes of short or long half-life, rich in neutrons, producing materials and radioactive substances of interest in diagnosis and medical therapy; generate long half-life radionuclides into short-lived or stable radionuclides of interest in burning radioactive waste or reducing the activity of unwanted radioactive sources; and generate fissile nuclides from the transmutation of fissile nuclides. In addition, it is useful in chemical concentration analysis tests by activating ready-made gamma ranges.

[002] Currently, radioisotope production technologies by isotope transmutation occur, essentially, based on four irradiation processes: fission neutron irradiation in Fission Reactors (RT), producing neutron-rich radioisotopes; irradiation of accelerated charged particles in Accelerators (AC), such as protons and alpha, generating proton-rich nuclides; photon irradiation, known as Photo-Transmutation (FT), emitted from sealed sources or from interactions of electrons with heavy targets, such as bremsstrahlung reactions; and, by Radioisotope Generators (GR), through the decay of a parent nuclide in a “son” where the father was previously produced by the RT or AC processes. The RT, AC and GR processes require specific apparatus to produce the transmutation.

[003] Among the documents that present devices that propose to produce radioisotopes by Photo-Transmutation (FT), the following are included:

[004] The patent application "Compact neutron generator for medical and commercial isotope production, fission product purification and controlled gamma reaction for direct electric power generation" - US20110268237A1 consists of a neutron generator, apparatus to produce radioisotopes and methods of use and commercial production of neutrons for medicine. This uses (y,n) reactions to produce neutrons by bombarding beryllium or deuterium with gamma photons. The interactions of these photons in matter produce neutrons, which are multiplied by a fission converter. It is observed that, due to the low neutron production of the reaction (y,n), the fissile material must be incorporated into the device to amplify the neutron flux. Thus, the neutron production method established in patent US20110268237 differs significantly from the present patent, which proposes the production of neutrons through d-d, d-t or t-t fusion reactions, and thus does not present a neutron amplifier.

[005] The document "Isotope generator1' - US20070160176A1 proposes to produce radioisotopes through the reaction (n,2n) or (v,n). The proponent suggests employing a neutron source that radiates a container adjacent to it, where samples are exposed to a neutron flux with the objective of generating isotopes. The reaction (n,2n) occurs in this container and produces the radioisotopes of interest. A limitation of this patent is associated to the decrease of the neutron flux due to the coupling of auxiliary systems constituted by heavy elements. The reaction in question requires high energy neutrons and is limited by the low probability of occurrence for most stable nuclides. After production, neutrons lose their energies by elastic (n,n') collisions with light elements; or inelastic, preferably with elements of intermediate atomic number, competing with any other type of nuclear reaction. Reactions (n,2n) are sporadic, compared to reactions (n,n'). neutron balance becomes precarious by self-adsorption competition reactions in the device itself in (n,n’) and (n,y) reactions. In the case in question, it is known that the reactions (n,2n) produce neutron-poor and proton-rich radioisotopes, and consequently, positron emitters (β+). Furthermore, reactions (n,2n) have a high energy threshold and low interaction cross sections (or interaction probability) for most nuclides. To achieve significant cross-section values, there is a remote possibility that reactions with tritium can generate neutrons with energies of 14.1 MeV. Furthermore, it is expected that there will be high neutron leakage from the compact device due to the high energy of the neutrons emitted. And, even the inherent moderation of the incorporated materials reduces the neutron energy making it difficult for reactions to occur (n,2n). The use of tritium characterizes the device as radioactive in nature.

[006] The patent 20070160176 differs from the present technology because it is based on reactions (n,2n), which requires specific targets for this purpose, in addition to the other drawbacks mentioned.

[007] In continuity, some patent documents associated with the processes of production of radioisotopes, AC, RT, GR are presented below. - Production from irradiation with accelerated particles, AC: emm "Device and method for producing radioisotopes" - US7940881, the authors propose to transmute isotopes by irradiating a fluid with a beam of charged particles. This patent is limited to the description of the target, its shape and physical state. Note that the beams of charged particles are generated by particle accelerators, as cyclotrons, synchrocyclotron or synchrotons The radionuclides produced are rich in protons and, in general, β+ emitters or decay by electronic capture.- Production from irradiation with neutrons (fission), RT: in “Techniques for on-demand production of medical isotopes such as Mo-99/Tc-99m and radioactive iodine isotopes including 1-131” - US20110280356, the inventor proposes to irradiate samples with neutrons from fission from uranium. In this case, the fast fission neutrons are reflected and scatter-moderated, increasing the probability of further fissions in the 238U. Sandwich-shaped layers of uranium are used to maintain the rate of fission and neutron production. In this case, the production of neutrons by fission becomes the key to supply the production of radioisotopes.- Production from a pre-existing “parent” radionuclide that decays, transmuting into another “child” radionuclide, GR process: in ''Medicai isotope generator systems” - US7554098, the inventors propose to use a 90Sr column to produce 90Y and separate it by means of an eluent solution. This is a typical patent featuring a columnar radioisotope generator containing a pre-existing long half-life radionuclide, which decays into a short half-life daughter radionuclide and can be eluted from the column. The “parent” radionuclide is produced by the methods described above, that is, in nuclear reactors or particle accelerators. These are chemically separated and confined in devices or capsules, where they will decay and produce the desired “daughter” nuclide. In this case, the “parent” nuclide, 90Sr, must be previously available, activated by other processes.

[008] The technical literature also presents patent documents with conceptions of neutron generating devices: - In the patent application US2013/0129027 A1, "High flux neutrons source", of May 23, 2013, an apparatus is presented for the production of thermal and epithermic neutrons, positioned around a cylinder or spherical moderator to maximize neutron flow to a sample centered in the center of a moderator void. In this case, the system is divided into a set of neutron generators with axial axes placed in the radial direction of a cylindrical structure. Each unit generates neutrons directed towards the center. The neutron fluxes generated from the multiple units are used for neutron activation analysis and ready gamma neutron activation analysis, in order to determine the chemical concentration of elements in a material. Thermal neutron absorptions and inelastic scattering of epithermic and fast neutrons in samples generate characteristic gamma rays that can be used to identify the target element and its chemical concentration. A radiation detector is positioned above the apparatus in the axial direction of the sample cylinder, surrounded by neutron generating units. Patent document US2013/0129027 A1 differs from this technology because, given its purpose of analyzing neutron activation, the structures and dimensions used are characteristic for this application, making it distinct. The multiple irradiation modules, placed radially to the axial sample cylinder, make the neutron generation system distant and, thus, susceptible to leakage with a reduction in the neutron flux. The spectra and fluxes generated in the device US2013/0129027 are insufficient for the proposed production of radioisotopes. Consequently, the geometric parameters diverge from the context proposed in this patent. - The patent US7639770B2, entitled "cylindrical neutron generator", presents a cylindrical neutron generator with coaxial formation, having a coaxial RF antenna plasma being produced, where in this plasma are generated the deuterium ions. Neutron generation is coaxial to the ion generator. The cylinder length is as long as necessary. Neutrons are generated from the collision of ions with a tritium or deuterium target. This device was designed for the production of neutrons for application in the oil field, analysis of molecules, investigation and scanning of explosives in airports, for example. Due to the lack of a moderator, this device could not produce radioisotopes, as the neutrons produced are generated by the dd or dt reaction, which are 2.45 and 14.1 MeV respectively, and at these energies the neutron absorption cross sections for most nuclides it is very low, with no transmutation reactions occurring.- The document US2008/0089460 A1, entitled “Proton Generator Apparatus for Isotope Production”, 2008, is related to improvements in electrostatic nuclear fusion reactors for neutron production and protons and associated particle generation. It has a cylindrical configuration endowed with a polygonal internal structure in the form of a reactor that uses fusion reactions between hydrogen and its isotopes with light nuclei. The system has an elongation where there is a collision zone in which impacts directed to the production of isotopes can be generated by the reaction of protons with appropriate nuclides. It is observed that the document addresses the production of radioisotopes through collisions with protons. Document US2008/0089460 differs from the present technology in that it includes an electrostatic inertial confinement fusion reactor core. This technology is well known in the fusion field, and requires the plasma to be produced and maintained in inertial confinement. In US2008/0089460, fusion reactions are generated by electrical pulses or particles that help heat the plasma. The resulting particles are neutrons and protons in a dispersed and isotropic form. However, only protons can be accelerated inside the device. In this case, radioisotope production reactions can only occur in the collision of proton-poor nuclides, inducing the production of β+ emitters. In this case, the nuclear interactions are different in the proposed technology. In summary: the document US2008/0089460 presents a fusion reactor with inertial confinement, where the deflection and orientations/interactions in the target involve protons that collide with proton-poor nuclides; whereas in the present application the reactions and interactions are with neutrons and neutron poor nuclides. Thus, the geometry, functionality, process, and technologies involved are divergent.

[009] In Radioisotope Generators - GR, the decay of a "father" nuclide into a "son" constitutes a natural transmutation, called radioactive decay; although, the “parent” nuclide must be produced by artificial means by the RT or AC methods. This type of generator is only viable when the “father” has a half-life much longer than the “son”. A typical example of this technology is the commercial generator of "Mo / "mTc.

[0010] In transmutation into neutron-rich nuclides, there is a need for a neutron-generating source. The production of neutrons can be done by fission reactors, RT. In fact, long half-life neutron-rich radionuclides have been produced by RT in Brazil: as 137Cs (30 years), 60Co (5 years), 1311 (8 days). Others, rich in protons, generated by AC, such as 18F (2 h), 201Ta (62.5 h), 67Ga (78.3 h), are found in Brazil, produced in commercial cyclotrons.

[0011] The production of neutrons can also be established by sealed radioactive sources emitting neutrons, for example, a source of 252Cf that emits neutrons by spontaneous fission; and, by d-d or d-t fusion reactions, for example, d-d or d-t type neutron generators, initially designed for research in the area of oil exploration. One of the main advantages of these generators is based on the cross sections of the d-d, d-t and t-t reactions, which reach significant values at relatively low acceleration voltages (a few hundred kV). The essence of the neutron generator technology is presented by Campos and Araújo (2010) (Araujo LW; Campos TPR/Vssues on beam-plasma instability Sept, 2010) and in more detail in Araujo LW's master's thesis entitled “Investigations in Compact Neutron Generators'' (UFMG/2010).

[0012] Transmutation is not only used to produce radionuclides. This technique can be used to convert long half-life radionuclides into short-lived or stable radionuclides. Thus, it is used to reduce the activity of radioactive waste or even sealed radioactive sources or unwanted liquids. In this case, the “burning” of radioactive waste produced in nuclear reactors can occur by inserting them in other reactors whose burning is produced during the process of fuel fission and production of electrical energy. Another possibility is the treatment and chemical separation, applied in conjunction with the technique of burning or not, where the radionuclides are separated into classes according to their half-life and activity. These are stored in pre-selected locations to be kept for millions of years to decay into a steady state.

[0013] The transmutation of nuclear fuels has also been researched involving high energy (1 GeV) proton accelerators, which through scattering reactions (p,n) in lead and bismuth nuclei, among others, produce multiple neutrons, which then they are used in the conversion of radioactive waste.

[0014] The transmutation of fissile nuclides into fissiles such as 232Th into 233U can occur in nuclear reactors that employ heavy water (D2O). Classic examples are the CANDU type heavy water reactors, which in this case transmute 232U into 239Pu, in addition to 232Th into 233U, in addition to producing electrical energy.

[0015] The process of Radioisotope Generators - GR is easy to use and low cost. There are several medical centers in Brazil that use "Mo/"mTc generators, distributed by the National Nuclear Energy Commission - CNEN. However, the country remains dependent on the import of irradiated "Mo, in a molybdenum substrate bound to alumina. The substrate activation is obtained in high neutron flux reactors in Canada, Netherlands, Argentina, Russia, Israel or the United States, specifically in the order 1013-1014 n.cm2s1. A recent global crisis in the supply of this input, which occurred between 2009 and 2011, due to the shutdown of foreign high-flow reactors for maintenance, impaired or even temporarily paralyzed the diagnoses made with radiopharmaceuticals labeled with "mTc in nuclear medicine. In the Brazilian case, the government solution consisted of investing in a high-flow reactor for the generation of "Mo; however, it will take at least a decade to be built and operated.

[0016] In the process of Photo-Transmutation - FT, unstable isotopes emitting gamma photons or produced by braking radiation of accelerated electrons are emitting sources of high flux of gamma radiation. Transmutation occurs through bombardment of target nuclei with gamma photons. Linear electron accelerators or even a large number of high-activity sealed sources are needed to supply gamma radiation for Photo-Transmutation. In FT, sealed sources are made up of unstable isotopes that continuously emit radiation; therefore, logistical problems are associated due to radiological protection associated with thousands of Ci (Curie) activity. This fact prevents the diffusion of this technology and, consequently, it is not used in the commercial production of radioisotopes.

[0017] In the process by nuclear reactors - RT, large industrial and energy installations are required, with high complexity and cost, in the order of billions of dollars, in addition, they generate concerns in terms of radiological protection and management of radioactive waste, and may also be possible the occurrence of severe nuclear accidents, which bring damage to populations and the environment.

[0018] In the production process by Accelerators - AC, most accelerators used in the production of radioisotopes cost in the order of tens of millions of dollars. The radioisotopes produced by this process are rich in protons, decay emitting β+ or by the electron capture method and have a short half-life. There is also a need for transport management from the production facility to the consumer center. For example, cyclotrons are facilities that produce β+ emitting radioisotopes, such as 18F, 11C and 15N. Such facilities are limited to proton-rich nuclides, making it impossible to produce β'-emitting radionuclides, which are rich in neutrons. The β'-emitting radionuclide class is produced solely with RT or FT.

[0019] The production of radioisotopes by sealed sources or neutron generators has not been used as a method of producing emitting radioisotopes (β‘). The reason is that the intensity of neutrons produced by the generator d-d or d-t, in an isotropic form, is in the order of 106 to 1011 n s'1 and is inversely proportional to the square of the distance to the target. Consequently, the fluence would reduce by a value around the fraction of 4πd2, for example, in relation to the distance of 100 cm from the target, the fluence would decrease by a factor of the order of 7.95 10’6 of it. In turn, the energy of the neutrons emitted from the dd or dt reactions in neutron generators is not suitable for the production of radioisotopes, as the cross sections are very low, in the order of a few millibarns (mb = 10'27 cm2), for vast majority of nuclides of interest. Thus, due to the inadequate energetic spectrum of the emitted neutrons, low surge and intensity reduction with the squared distance, the use of such technology for neutron nuclide transmutation, for medical purposes, has become fruitless. Thus, arrangements using commercial devices for the production of radioisotopes are non-existent and impractical.

[0020] Sealed sources of 252Cf can reach surges in the order of 1012 n s’1; however, they emit gamma radiation simultaneously with neutrons, the energy spectrum of the neutrons is fission with maximum energies of 14 MeV, they decay with time with a half-life of 2.7 years, the neutron emission cannot be interrupted, in addition to being necessary to replace them periodically.

[0021] In the case of insertion of radioactive waste in reactors, the possibility of nuclear accidents, associated with chemical explosions, make such technological processes unacceptable to our society. In Brazil, the treatment of tailings from Angra I, II and, in the future, III plants is still an unsolvable problem. Transmutation by spallation reactions involves high-energy (approximately GeV) proton accelerators coupled to nuclear reactors. Such installations are costly (billions of dollars) and are still experimental.

[0022] In the case of transmutation of thorium into uranium, light water reactors, pressurized type - PWR (Pressurized Water Reactor) cannot transmute fissile elements into fissiles on a large scale, due to the low neutron economy. For each neutron absorbed in 235U (fuel) 2.3 neutrons are emitted. Continuing the chain reaction requires 1 neutron and the remainder either escapes from the reactor or is absorbed. This is because light water (H2O) is a neutron absorber. Thus, there is a deficit of neutrons to transmute elements of interest inside the reactor. Although Brazil has one of the largest reserves of 232Th in the world, its use has not yet occurred, and it is still useless to date. The transmutation of this element into a fissile element, in the 233U case, is of interest to the nation, due to the possibility of increasing the capacity of electrical production by nuclear reactors.

[0023] Basically, the complexity, high cost, dimensions and radiological protection involved in the generation of radioisotopes by FT, RT and AC techniques, limit the applications of radioisotopes. Neutron-rich radionuclides, especially those with a short half-life, less than 48 hours, for example, in a non-limiting way, are not produced. Obviously, the distance from the production centers by any of the FT, RT and AC techniques prevents the use of short half-life radionuclides.

[0024] In addition, the disposal of radioactive waste in locus has not yet been resolved in Brazil. Such limitations can be overcome by applying the in locus transmutation method, through activation by neutrons, generated by compact generators, supported by fusion reactions. The main advantage is characterized by the cross sections of the d-d, d-t and t-t reactions, which reach significant values at relatively low acceleration voltages (a few hundred kV) used in the acceleration of these particles.

[0025] Aiming at solving such existing limitations both in the production of radioisotopes, as well as related patents, the present invention is proposed in order to increase: i) the supply of short-lived neutron-rich radioisotopes; ii) the independence of high flux reactor technology in the activation of 99-Mo, available only in a few industrialized countries; iii) the production of short half-life radioisotopes in hospitals or clinics; iv) the possibility of transmuting long half-life radioisotopes into short-lived or stable radioisotopes, in locus, solving the problem of waste produced in nuclear reactors, or from undesirable sealed sources; v) the possibility of transmuting fissile elements into fissiles, allowing the use of the country's 232Th mineral reserves; vi) reducing the cost of transmutation of radioisotopes; vii) replacing complex technologies, such as nuclear fission reactors and particle accelerators, by simpler and more compact technologies; ) the maintenance of the philosophy of compact radioisotope generators, but without dependence on the pre-existence of a radioactive parent nuclide produced in fission reactors or particle accelerators; ix) the radiological safety of the facilities; x) and allow total shutdown of the installation and consequently interruption of radiation produced in the device, similar to X-ray equipment.

[0026] The present invention was then developed through the proposal of the Linear Shape Isotopic Transmutator Fusor Cell (CLFTI).

[0027] The CLFTI proposal consists of employing neutron generation technologies by d-d, d-t or t-t fusion type and internal neutron moderation, reflection and shielding systems, together, composing a nuclear transmutation system. In this context, the CLFTI is distinguished by being a unitary system, capable of jointly administering the main electromagnetic and nuclear processes involved in the transmutation of nuclides. The system has compact dimensions, low cost compared to competing technologies, simplicity of development and operation, presenting radiological safety with the possibility of complete interruption of radiation and availability, being able to operate continuously in the production of radioisotopes, at the site of application of the radioisotopes, consequently enabling the production and use of neutron-rich radionuclides with a short half-life.

[0028] The present technology is compact, simpler (compared to a nuclear reactor or a particle accelerator) and capable of producing radioisotopes, or transmuting several isotopes or radioisotopes of interest, in the place of use thereof, for example, in hospitals, clinics, research centers, radioactive waste production sites, at a low cost. Another relevant aspect in the production of radioisotopes provided by this technology is the ability to turn the device on and off, powered by radio frequency and high electrical potentials, in the order of 200 kV. Thus, when turning off, the device stops producing radiation, in a similar way to a conventional X-ray machine. Contrary to nuclear reactors, which do not cease the production of radiation, and adverse to technologies that use the production of neutrons by 252Cf sources, or photodisintegration reactions such as (y,n); CLFTI is attractive because it does not produce radiation when turned off.

[0029] Finally, the present technology is in comparing the production of radioisotopes by generators, defined in this application by GRs. In GRs there is a need for a precursor, called “father”, radioactive, produced in advance in nuclear reactors. The distribution of generators, such as "Mo/"mTc are done weekly, and present an eluted activity, decaying in the half-life of the father, for example, 67 h of "Mo. The balance of activities between "Mo and "mTc is said transient. In the technology presented, the CLFTI can continuously generate the "father", whose internal activity in the device becomes constant, and consequently the balance between the "father" and "son" becomes secular. father, therefore, is ceased as soon as the CLFTI is turned off.In addition, it is possible to make the “son” radioisotope available in an unlimited way, without the need for periodic exchanges of GRs.

BRIEF DESCRIPTION OF THE FIGURES

[0030] Figure 1 shows the longitudinal section of the linear isotopic transmutator fuser cell (CLFTI) and its main components and auxiliary systems.

[0031] Figure 2 shows the semi-transparent three-dimensional view of the CLFTI, without the shield, illustrating the shield (43) and (42), reflector (41) and sample input (37).

[0032] Figure 3 illustrates some of the structures of the CLFTI in isolation, so that (a) illustrates the plasma chamber receptacle (38), the electrical insulator (39), the moderator receptacle (40) and the input of samples (37); (b) represents the same structures; and (c) represents the shielding layer (42) and the cover (43).

[0033] Figure 4 illustrates the internal structures, such as the plasma chamber (38), the set of electrodes (31), (32), (33), (34) and (35), the moderator (36) and sample receptacle (37). Figure 5 illustrates the set of electrodes, showing them in isolation and together.

[0034] Figure 6 illustrates the distribution of equipotential lines of electrical potential generated between the plasma electrodes (31) and the target electrode (35).

[0035] Figure 7 illustrates the ion transport lines between the plasma electrodes (31) and the target electrode (35).

[0036] Figure 8 illustrates the energy spectrum of neutrons in the moderator.

[0037] Figure 9 illustrates the cross-sections for the reactions of d-d (a) and d-t (b).

DETAILED DESCRIPTION OF THE TECHNOLOGY

[0038] The present technology is proposed by an Isotopic Transmuting Linear Fusing Cell (CLFTI) (Figure 1) which consists of an arrangement of components along a linear segment where five distinct types of electrodes are arranged: a plasma electrode (31 ), a suppressor electrode (32), a ground electrode (33), a focusing electrode (34), and a target electrode (35). Basically, in the CLFTI there is a plasma chamber (38), an acceleration environment where the electrodes are located, and a neutron moderation receptacle (40), containing a sample receptacle (37). The electrode system was previously researched and can be better understood in (Araujo LW; Campos TPR, "The modeling of a linear multibeam deuteron compact accelerator for neutron generation", Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, v.679, p. 97-102, 2012).

[0039] The present technology (Figure 1) consists of a plasma and ion generator system, consisting of a plasma chamber (38) in format and internal (46) or external (45) radio frequency (RF) antennas; a geometrically optimized arrangement of electrodes, along a linear segment where a plasma electrode (31) is arranged, in cylindrical shape, with 1 to 100 openings per square centimeter of area, thickness between 0.2 and 5 cm; a suppressor electrode (32), in cylindrical shape, with the same number of openings as the plasma electrode, positioned from 0.4 to 2.5 cm from the plasma electrode; a ground electrode (33), in cylindrical shape, with the same number of openings, positioned 0.9 to 3 cm from the plasma electrode; a focusing K electrode (34) cylinder-shaped, 1-5 cm long, with a frusto-cone-shaped opening, positioned 1-12 cm from the plasma electrode; a target electrode (35), in cylindrical shape and thickness between 0.1 and 2 cm, positioned 4 to 20 cm from the plasma electrode, the target being covered with metal hydride on the face exposed to the beam, capable of incorporating deuterium or tritium ; target isolator and refrigeration system (48) with circulating internal refrigerant; moderator receptacle (40), cylindrical, adjustable, filled with a low molecular weight substance, called moderator (36); one or more sample receptacles (37), cylindrical in shape; surrounded by a neutron reflector (41) and a shield (44), with a thickness ranging from 1 to 80 cm.

[0040] The target (35) consists of a film of metal hydrides, which is preferably titanium-deuterium (TiDx), where x varies from 0.1 to 6, in a non-limiting manner, deposited on the metal electrode plate of the target. The refrigeration system is composed of metallic heat exchanger and refrigerant (52). The refrigerant (48) preferably consists of mineral or organic oil. The electrodes (31), (32), (33), (34) and (35) have multiple perforations in a cylindrical shape and, as well as in a frusto-cone section, or a sphere section, and are made of copper, aluminum , silver, gold, titanium, or metal alloy of these. Electrodes (31), (32) and (33) have the same number of openings and opening shapes and orientations. Electrical insulators (39) consisting of electrical insulating material, which can cover the unexposed face of the target electrode, the joints and edges of the electrodes, as well as at the entrances of high voltage electrical connections, between these conductive materials and other parts of the device, are made of dielectric material such as glasses, special insulating ceramics, and rubber, in a non-limiting manner. The moderator (36) is a shell that can be filled with one or more substances of low molecular weight and reduced neutron absorption, such as light water (H2O), heavy water (D2O), graphite, high density polymers, polyethylene, teflon , beryllium compounds, or mixtures thereof. The reflector (41) is metallic, preferably made of chromium, copper, bismuth, lead, tungsten carbide or alloys or mixtures thereof. The shield (43) and (44) can be composed of polyethylene, water, or graphite, mixed with a neutron absorber, such as boron or lithium based substances, and coated with bismuth, lead, or tungsten carbide; and the gas (53) from the plasma chamber (38) may be neutral deuterium, or enriched with tritium gas.

[0041] More specifically, the CLFTI (Figure 1) comprises a plasma chamber (38), in cylindrical shape, with a radius between 2 to 100 cm and a length between 3 to 30 cm and internal radio frequency (RF) antennas ( 46) or external (45); an arrangement of electrodes along the axial axis, where a plasma electrode (31) is arranged, in cylindrical shape, with a radius of 2 to 100 cm, with 1 to 100 openings per square centimeter, so that these openings have radii between 0.1 and 10 mm and thickness between 0.2 and 5 cm; a suppressor electrode (32), in cylindrical shape, with a radius of 2 to 100 cm and a thickness between 0.2 and 1 cm, positioned 0.4 to 4 cm from the plasma electrode; a ground electrode (33), in cylindrical shape, with a radius of 2 to 100 cm, thickness between 0.2 and 1 cm, positioned 0.9 to 4 cm from the plasma electrode; and the plasma electrodes (31), suppressor (32), grounded (33) maintain the same number of openings and dimensions, each opening may have a cylindrical shape, or cone or sphere trunk with radii between 0.1 to 10 mm; a focusing electrode (34), in the form of a cylinder, with a length of 1 to 5 cm, with an opening in the shape of a frustum of cone, with a smaller radius between 1 and 100 cm and larger between 3 and 100 cm, positioned from 1 to 12 cm from the plasma electrode; a target electrode (35), in cylindrical shape with a radius between 2 and 100 cm and a thickness between 0.1 and 2 cm, positioned 4 to 20 cm from the plasma electrode, the target being covered with metal hydride on the face exposed to the beam , capable of incorporating deuterium or tritium; target isolator and refrigeration system (48) with circulating internal refrigerant; the moderator receptacle (40) , in cylindrical shape with a radius ranging between 2 and 100 cm and length between 4 and 80 cm, adjustable, filled with a low molecular weight substance, called moderator (36); one or more sample receptacles (37), in cylindrical shape with a radius ranging between 2 and 10 cm and a length between 2 and 50 cm; surrounded by a neutron reflector (41) and a shield (44), with a thickness ranging from 1 to 80 cm; the target (35) consists of a metal hydride film, which is preferably titanium-deuterium (TiDx), where x varies from 0.1 to 6, deposited on the target's metal electrode plate; the refrigeration system (52) is composed of the heat exchanger and circulation pump; the refrigerant fluid (48) consists of mineral or organic oil; the electrodes (31), (32), (33), (34) and (35) are made of copper, aluminum, silver, gold, titanium, or their metallic alloy; the electrical insulators (39) are made of electrical insulating material, which can cover the unexposed face of the target electrode, the joints and edges of the electrodes, as well as at the entrances of high voltage electrical connections, between these conductive materials and other parts of the device, made of dielectric material such as glasses, special insulating ceramics or rubber; by the moderator (36) which is a casing that can be filled with one or more substances of low molecular weight and reduced neutron absorption, such as light water (H2O), heavy water (D2O), graphite, high density polymers, polyethylene, teflon, beryllium compounds or mixtures thereof; by the metallic reflector (41), preferably of chromium, copper, bismuth, lead, tungsten carbide or alloys or mixtures thereof; by the shield (43) and (44), composed of polyethylene, water, or graphite, mixed with a neutron absorber, such as boron or lithium based substances, and coated with bismuth, lead, or tungsten carbide; by the gas (53) that fills the plasma chamber (38) which is either neutral deuterium, or enriched with gaseous tritium.

[0042] The moderator casing (40) and the sample receptacle (37) can constitute a single element, so that the target nuclides can be inserted and combined in the moderator.

[0043] The CLFTI can connect to a radio frequency power system - RF (50), a high voltage system (51) with power connections for the electrodes (56), and a gas supply system for deuterium (D2) (53) and (54).

[0044] The present device proposes a geometrically adequate structure, using suitable materials, that is, the configurations and types of materials and geometries allow to maximize the emergence of neutrons; reducing leakage by neutron reflection, in addition to adjusting the neutron energy spectrum through neutron moderation with the moderator elements, enabling the generation of a neutron flux in a set of receptacles, capable of transmuting nuclides producing radioisotopes, among other applications. This modulated neutron flux originates from nuclear reactions dd or dt, and the deuterium ions, generated in plasma, are extracted from the plasma chamber by an electrode positioned on its cylindrical face, accelerated by the potential difference present between a set of electrodes , and caused to collide with a target consisting of deuterated or tritiated hydrides, promoting nuclear reactions in the target.

[0045] The cylindrical containment of the plasma allows the insertion of an internal or external radiofrequency antenna, producing the excitation and ionization of the deuterium gas, and its axial removal by the plasma electrode, towards the target.

[0046] Through an isolation and refrigeration of the target electrode (35) of high potential, the moderator (36) can be brought closer to it, allowing neutrons to lose their energies by elastic collisions and reach plausible kinetic energies to occur absorption reactions and radioactive capture, preferably in the thermal range, in sample receptacles. Thus, radioisotope generation processes such as GR, FT, AC and RT become outdated and unnecessary.

[0047] The present technology is compact, simpler and capable of producing radioisotopes or transmuting various isotopes or radioisotopes of interest at the place of application thereof, for example, in hospitals, clinics, research centers and radioactive waste production sites, at a low cost.

[0048] When dealing with the production of radioisotopes, a relevant aspect of this invention is the ability to turn on and off. Thus, by turning off the d-d fusion-based device, radiation is no longer produced. This feature of the CHFTI resembles the ability to turn a conventional X-ray machine off and on. Contrary to nuclear reactors, which do not cease the production of radiation, and, adverse to technologies that use the production of neutrons by 252Cf sources, or photodisintegration reactions such as (y,n), CLFTI, based on dd fusion, becomes attractive because it does not produce radiation when turned off.

[0049] Another relevant aspect of the present technology is in the comparison of the production of radioisotopes by radioactive “father’7”son type generators, defined by GRs. In GRs there is a need for a radioactive precursor, called “father”, to be produced in advance in nuclear reactors. The distribution of generators, such as "Mo/"mTc are done weekly, and present an eluted activity, decaying in the half-life of the father, for example, 67 h of "Mo. The balance of activities between "Mo and "mTc is said transient because both decay and reduce their activities exponentially as a function of the father's activity, 5 to 7 days. In the presented technology, CLFTI can continuously generate the "father", whose internal activity in the device becomes constant depending on production reaction rate and, consequently, the balance between the “father” and “son” becomes secular, thus it is possible to make the radioisotope “son” available in an unlimited way, without the need for periodic exchanges of GRs.

[0050] As for the main components of the CLFTI (present invention), as well as its functionalities, the CLFTI consists of: Plasma generator (50), (38), (45), (46) and (47) and ion extractor (31) (32) (33): a plasma generator and ion source, represented by a chamber for containing the plasma (38) and deuterium ions, extracted from the plasma (47) fed by the D2 gas (54) provided by a gas storage and distribution system (53); radio frequency antennas, internal (46) or external helical (45). Gas storage and distribution system (53) and (54): consisting of a cylinder with pressurized deuterium gas (53), pressure control valves (53) , which should establish a pressure in the order of approximately 0.27 Pa inside the plasma chamber, and tubes and connectors that feed the plasma chamber (38). Electrode Set (31), (32), (33), ( 34) and (35) (Figure 5): responsible for defining a bundle of nuclei of hydrogen isotopes, deuterium (d) or tritium (t) ions. An individual fixed voltage is applied to the electrodes, ranging from 30 to -150 kV, responsible for extracting, focusing and accelerating the deuterium ions. This set comprises a plasma electrode (31), suppressor electrode (32), ground electrode (33), focusing electrode (34) and electrode associated with the target (35). Radiofrequency power system (50): radiofrequency generator, impedance matching network and power amplifier, which feeds the RF antenna (45) or (46), which must operate with power in the order of kilowatts (>5 kW) with a frequency of 13.56 MHz, and cooling system .Cold (35) target: consisting of metal hydrides deposited on the target metal electrode plate (35), where dd (deuteron-deuteron), dt (deuteron-triton) or tt (triton-triton) fusion reactions are produced , generating neutrons; Cooling system (52), (48): heat exchanger (52) and refrigerant fluid (48), consisting of insulating oil (48), which flows over the metal that maintain contact with the target, surrounding it. o in order to absorb the thermal energy deposited on the target of the accelerated ions. Moderator receptacle (40): a receptacle the one with radius ranging between 2 and 100 cm and length between 4 and 80 cm, where there is a neutron moderating material (36) of adjustable dimensions, in order to improve the energy spectrum of the neutron beam to the transmutation of interest, maximizing the rate of transmutation reaction. Sample receptacle assembly (37): location for introduction of samples to be transmuted, internal or lateral to the moderator; Neutron reflector (41): a neutron reflection housing, which minimizes neutron leakage or absorption in order to confine the neutrons inside the moderator; Shield (44) (43): external casing that limits radioactive exposure to the vicinity of the device, during the period of operation.

[0051] The CLFTI connects to a radio frequency power system - RF (50), a high voltage system (51) with power connections for the electrodes (56), and a deuterium gas supply system (D2) (53) and (54).

[0052] Among some materials that can be used in the constitution of the main components of the present invention, the following are cited: Electrodes (31), (32), (33), (34) and (35): solid metal parts, with multiple perforations in cylindrical shape, frusto-cone section, or sphere section, made of copper, aluminum, silver, gold, titanium, or metallic alloy, in a non-limiting manner. Target (35): film deposited on the target electrode, composed of metal hydride, which is titanium, in a non-limiting manner. Insulator (39): ceramic electrical insulating material, in a non-limiting manner, applied to the separation of the electrodes and their edges, as well as to the inputs of the high electrical connections voltage.Refrigerant (48): refrigerant fluid to the target (48), electrical insulator, such as mineral or organic insulating oil, in a non-limiting manner, applied in the process of refrigeration and electrical isolation of the target (35).Moderator (36): casing filled with light water (H2O), heavy water (D2O), graphite, high density polymers, polyethylene, teflon, beryllium compounds, or mixtures thereof, in a non-limiting manner.Reflector (41): chromium, copper, bismuth, lead, tungsten carbide or alloys or mixtures thereof, in form non-limiting.Shield (44), (43): composed of polyethylene, water, or graphite, mixed with a neutron absorber, such as boron or lithium-based substances, and coated with bismuth, lead, or tungsten carbide, to form non-limiting.Gas (53): The plasma chamber feed gas (38) is neutral deuterium gas, or enriched with tritium gas.

[0053] According to Figure 1, the CLFT contains a set of internal structures, namely: the plasma chamber receptacle (38); the moderator receptacle (40); the set of electrodes (31), (32), (33), (34) and (35), wrapped and separated by an electrical insulator (39). Separating the moderator receptacle (40) from the target electrode (35) there is a chamber that circulates the circulating refrigerant (48) which has the function of electrical isolation and cooling of the target (35). The sample receptacles (37) can be just one or a set distributed internal to the moderator (36). The entire structure is covered by a neutron reflector (41) and a shield (44). There is a cover (43) also composed of a reflector and shielding, which gives access to the sample receptacles (37).

[0054] The moderator casing (40) and the sample receptacle (37) can be restructured into a single element, so that the target nuclides can be inserted and combined in the moderator, composing a radioisotope transmuting moderator unit.

[0055] Figure 2 shows the three-dimensional wireframe structure of CLFTI, with semi-transparency. In this only the neutron reflector layer (41), the shield (42), the sample receptacle entrance (37), and the shield cover (43) are indicated. Interning you can see the distribution of electrodes between the plasma chamber and the moderator.

[0056] Figure 3(a) illustrates the plasma chamber receptacle (38), the electrical insulator (39), the moderator receptacle (40) and the sample inlet (37). Figure 3(b) shows the same structures. Figure 3(c) shows the shield layer (42) and the cover (43).

[0057] Figure 4 illustrates in greater detail the distribution of electrodes (31,32, 33, 34, and 35) between the plasma chamber and the moderator (36). The suppressor electrode (32) and the ground electrode (33) are identified, whose geometries are equivalent, and the suppressor electrode (32) is positioned 0.1 to 15 mm away from the plasma electrode (31) and the electrode grounded (33). In turn, the ground electrode (33) is positioned 0.1 to 20 mm from the plasma electrode (31). The suppressor (32) and ground (33) electrodes have thicknesses from 1 to 10 mm, and equipped with multiple cylindrical openings from 0.1 to 10 mm in radius and symmetrically spaced from 2 to 30 mm, together, of non-limiting measures .

[0058] The electrodes can be better identified in Figure 5, where they are presented individually.

[0059] Figure 5(a) shows the image of the plasma electrode (31), which is similar to the suppression (32) and grounded (33) electrodes, having the same number of perforations and diameters.

[0060] Figure 5(b) illustrates the focusing electrode (33) with an opening in conical trunk geometry with differentiated internal and external radius, forming a cone trunk, positioned posterior to the ground electrode (32) and away from the electrode of the plasma (31) in an isolated way.

[0061] In Figure 5(c) the joint configuration of the electrodes is illustrated, so that: plasma electrode (31), provided, in this example case, with 6 symmetrically distributed openings, where each opening has a circular shape, positioned after the suppressor electrodes (32), ground (33), focuser (34) and target electrode (35).

[0062] Figure 6 illustrates the distribution of equipotential lines of electrical potential generated between the plasma electrodes (31) and the target electrode (35).

[0063] Figure 7 illustrates the ion transport lines between the plasma electrodes (31) and the target electrode (35).

[0064] Figure 9 illustrates the energy spectrum of neutrons in the moderator.

[0065] In the CLFTI, as mentioned, there is a set of three electrodes (plasma (31), suppressor (32), grounded (33)) of solid cylindrical shape with thicknesses from 01 to 20 mm, and equivalent radii from 1 to 100 cm, with 01 to 100 openings per square centimeter in the shape of a sphere section, trunk sector, or cylindrical, with radii between 0.1 to 10 mm. (Figures 1 and 3). These are positioned parallel to each other and spaced from 0.1 to 30 mm apart, in a non-limiting manner. It is also possible to identify the plasma chamber (38) in cylindrical shape with a radius between 2 and 100 cm and a length between 3 and 50 cm. Meanwhile, the structure for moderation of neutrons (36), in cylindrical shape, admits a radius varying between 2 and 100 cm and a length between 4 and 50 cm. The sample receptacle (37), in cylindrical shape, assumes a radius varying between 2 and 10 cm and a length between 2 and 20 cm.

[0066] In the target electrode (35) nuclear reactions occur, dd or dt as indicated in the expressions below: d + 2H ->3He (0.82 MeV) + n (2.45 MeV), Q = 3.270 MeV ( 50%) (1)d + 2H 3He + (1.01 MeV) + 1H (3.03 MeV), Q = 4.04 MeV (50%) (2) d + 3H ->4He (3.52 MeV ) + n (14.06 MeV), Q = 17.590 MeV (3) where d is equivalent to the isotope of hydrogen, 2H and teequivalent to the isotope of hydrogen 3H, and p is equivalent to hydrogen (H1), Q represents the kinetic energy of the products of reaction, where n is emitted with 2.45 MeV in dd reactions and 14.06 MeV for dt. Reactions 1 and 2 can occur on the target, ie d-d, which generate (d,n') and (d,p). However, only reaction 6 has neutron emission as a by-product.

[0067] The cross sections (probability of interaction) for the reactions (d,n'), (d,p), (d,d), (t,n), obtained from the ENDF/B-VI database .8, are shown in Figure 10.

onde rjdé o número de dêuterons por cm3 no alvo, / é a corrente do feixe, odd(E) é a seção de choque para produção de nêutrons da reação de fusão d-d em função da energia E do feixe de dêuterons. As espécies iônicas foram ponderadas pela sua fração fk e pelo número de núcleos k por ions. A expressão dE/dx representa o poder de frenagem do alvo carregado com deutério. A equaçãol foi resolvida numericamente, discretizando a energia em intervalos de 30 keV e estimando a densidade de dêuterons no alvo pd igual a 3,76 g.cm'3, com base no relatório técnico de 1954, da Universidade da California, intitulado: “Information on the Neutrons Produced in the H3(d,n) He4’’, de Jack Benveniste and Jerry Zenger.A Lei de Bragg foi empregada para determinar o poder de frenagem no alvo, ela é apresentada por meio da equação 2 e é descrita por Heaton, R.; Lee, H.; Skensved, P. e Robertson, B. na publicação da Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 276(3):529 - 538, 1989).

onde o índice M representa o metal e d representa o deutério no alvo. Os valores do poder de frenagem podem ser obtidos por meio do código Srim.[0068] The determination of the neutron yield, y, of the CLFTI can be evaluated using equation 1.

where rj is the number of deuterons per cm3 in the target, / is the beam current, odd(E) is the neutron cross-section for neutron production of the fusion reaction dd as a function of the energy E of the deuteron beam. Ionic species were weighted by their fk fraction and the number of k nuclei per ions. The expression dE/dx represents the braking power of the target loaded with deuterium. The equation was solved numerically, discretizing the energy in 30 keV intervals and estimating the density of deuterons in the target pd equal to 3.76 g.cm'3, based on the technical report of 1954, from the University of California, entitled: “ Information on the Neutrons Produced in the H3(d,n) He4'', by Jack Benveniste and Jerry Zenger.Bragg's Law was used to determine the target's braking power, it is presented through equation 2 and is described by Heaton, R.; Lee, H.; Skensved, P. and Robertson, B. in Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 276(3):529-538, 1989).

where the index M represents the metal and d represents the deuterium in the target. Braking power values can be obtained via the Srim code.

Onde À representa a constante de meia vida do radionuclídeo, produto da transmutação. A taxa de transmutação volumétrica Rv pode então ser obtida por meio da equação 4.

Onde p representa a densidade do material representativo da amostra (Z), NA o número de Avogadro, Aéa massa atômica do composto contendo isótopo Z a ser transmutado, co é a fração química multiplicada pela fração isotópica do isótopo Z no composto, e (JZ(E) a seção de choque de absorção neutrônica do isótopo em questão e Φ(E,r) o fluxo de nêutrons no moderador na posição r (da amostra), ambos dependente da energia, e y o rendimento de nêutrons gerados pelas reações d-d, que significa a surgência de nêutrons no alvo. O termo <αz(E).Φ(E,r)>/y é avaliado pelo código MCNP em uma determinada posição r do moderador, e integrado no domínio do espectro energético, entre a energia térmica a 2,5 MeV. Os resultados destes cálculos para algumas amostras são apresentadas nos exemplos.[0069] After obtaining the neutron yield, Eq.1, referring to the neutron emission source distributed in the target, the spatial distribution of neutrons and its spectrum in the volume of the moderator is calculated, in an attempt to assess the degradation of the spectrum fast (2.45 MeV emitted by dd, for example) in the thermal spectrum. In the regions where the samples are located, the macroscopic cross section of the material to be irradiated is obtained, multiplying the microscopic cross section of transmutation (in general, of radioactive capture, (n,v)), dependent on energy, by the spectrum neutron, normalized by the neutron yield by the source, and finally by the volumetric density of atoms to be transmuted, in atoms-cm3. Then, the temporal and volumetric rate of radioisotope transmutation, defined as Rv, in units of nuclide produced “nr” per unit volume, cm3 , per unit of fluence emitted by the source, ie n.s'1. This is multiplied by the yield y of the CLFTI and inserted in equation 3, in order to define the sample activity as a function of the irradiation time t.

Where À represents the half-life constant of the radionuclide, the product of transmutation. The volumetric transmutation rate Rv can then be obtained from equation 4.

Where p represents the density of the representative material of the sample (Z), NA the Avogadro number, A is the atomic mass of the compound containing isotope Z to be transmuted, co is the chemical fraction multiplied by the isotope fraction of the isotope Z in the compound, and (JZ (E) the neutron absorption cross-section of the isotope in question and Φ(E,r) the neutron flux in the moderator at position r (of the sample), both energy dependent, and y neutron yield generated by the dd reactions, which means the emergence of neutrons in the target. The term <αz(E).Φ(E,r)>/y is evaluated by the MCNP code at a given position r of the moderator, and integrated in the domain of the energy spectrum, between the thermal energy at 2.5 MeV. The results of these calculations for some samples are shown in the examples.

[0070] Regarding the non-thermalized plasma (47), produced in the low temperature plasma chamber (38), these can be generated by electrical discharges, in continuous (CW) or pulsed operation, in a capacitive and inductive way coupled to radio frequency discharges, antenna discharges, and microwave discharges in closed cavities, or even in open structures. Capacitive coupled discharge can occur between two parallel plates or transverse electrodes where an alternating potential difference is applied. Inductive coupled discharge is generated by the induction of a coil. The plasma (47) can also be generated by a strong electromagnetic field applied with a laser or microwave generator, or by applying a strong electric field to a gas where the Townsend avalanche process takes place. The Townsend discharge process is an ionization process where free electrons are accelerated by the electric field, strong enough to generate an electrical conduction in the gas in the form of an avalanche multiplication caused by the impacts of ions and ionized molecules. RF radio frequency plasma generation is of interest when long-term operation is required. Electrical discharges applied by the plasma generator can be classified by the frequency of the excited field, which may vary from kHz to MHz, classified as: by direct current discharges (DC); pulsed DC discharges (kHz); radio frequency (MHz) discharges, supported by electron heating mechanisms through ohmic and stochastic means; by microwave discharges (GHz); by laser generated plasma; or by oriented electron beam discharges. In summary, there are several forms of plasma generation, whose science and technology are in the public domain. Changing the way in which the plasma is generated in the plasma chamber, described in this patent, while maintaining similar geometry, material or components, and preserving its use, does not characterize a new invention, but merely represents changes in the form of ionization of deuterium gas, supported by scientific and technical information of common knowledge.

[0071] CLFTI can transmute and produce neutron-rich radionuclides, preferably from the group comprising: Na-24, P-32, S-35, CI-38, Ar-41, K-42, Ca-47, Ca-49 , Ti-51, V-52, Cr-55, Mn-56, Fe-59, Co-60, Ni-65, Cu-64, Cu-66, Zn-69, Zn-71, Zn-72, Ga -70, Ga-72, Ge-72, Ge-75, As-76, Se-81, Se-83, Br-80, Br-82, Kr-87, Kr-85, Kr-81, Kr-79 , Rb-86, Rb-88, Sr-85, Sr-87, Sr-89, Sr-90, Y-90, Mo-99, Ru-105, Ru-106, Rh-104, Pd-103, Pd -107, Ag-108, Ag-110, Ag-111, Ag-113, Cd-111, Cd-115, Cd-117, ln-114, ln-116, ln-114, ln-116, Sn-125 , Sn 121, Sn-123, Sb122, Sb123, Sb125, Te-121, Te123, Te125, Te-127, Te-129, Te-131, 1-128, 1-131, Xe-125, Xe-127, Xe-129, Xe-131, Xe-133, Xe135, Xe-137, Cs-134, Ba-133, Ba-135, Ba-139, Ba-130, La-140, Ce-137, Ce-139, Ce-141, Ce-143, Pr-142, Pr-143, Nd-147, Nd-149, Nd-151, Sm-151, Sm-153, Sm-155, Eu-152, Eu-154, Eu-155 , Eu-156, Gd-153, Gd-159, Gd-161, Tb-160, Dy-157, Dy-159, Dy-165, Dy-166, Ho-166, Er-169, Er-171, Tm -170, Yb-169, Yb-175, Yb-177, Lu-177, Hf-175, Hf-181, Hf182, Hf-177, Hf-178, Hf-179, Ta-182, W181, W185, W-187, W188, Re-188, Os-193, lr-192, lr-193,lr- 194, Pt-191, Pt-193, Pt-195, Pt-197, Pt-199, Au-1998, Au-199, Hg-197, Hg-199, Hg-203, Hg-205, Ti-204, Ti-206, Pb-205, Pb-209, Bi-201, Bi-211, Th-233, U-239.

[0072] The CLFTI cell can also transmute one or more of the long half-life radionuclides, precursor of a short half-life radionuclide, this pair being defined in the group: Mo-99/Tc-99m, Sr-90/Y -90, Rb-81/Kr-81m, Hg-195/Au-195m; W-188/Re-188, SI-32/P-32, in a non-limiting manner.

[0073] The CLFTI cell can eliminate radioactive waste, producing short half-life nuclides, in the transmutation of long half-life nuclides from the group of californium, berkelium, curium, americium, plutonium, netunium, uranium, protactinium, thorium, actinide, radio , strontium, iodine, cesium, cobalt, iron, sodium, in a non-limiting form, commonly existing and produced in nuclear fuels in nuclear reactors. CLFTI can also transmute fissile into fissile nuclides, such as Th-232 to U-233 and U-238 to Pu-239.

[0074] In addition, this device can be useful in chemical concentration analysis tests by activating ready ranges. This is a unit that the moderator is superimposed on the cylindrical target, which is on its lower cylindrical face, having a free and easily accessible upper face. At this stage, a spectrum of particles with less gamma and neutron contamination can be expected, and can even be filtered by thermal and gamma neutron filters. One can then use part of this area to collect ready gamma produced by the irradiated samples inside the moderator, from the positioning of gamma ray detectors associated with a gamma spectrometry system. The characteristic gamma rays emitted immediately (ready) after the capture of neutrons in the nuclei of the atoms of the samples positioned in the moderator allow the chemical and nuclear characterization of the elements present.

[0075] The present technology can be better understood through the following non-limiting examples.

Example 1: Electromagnetic assessment of CLFTI

[0076] As an example of the electromagnetic evaluation, the electrical potential distribution of a CLFTI simulated in the CST code (Computer Simulation Technology) is presented. In this, an electrical potential of 30 kV in the plasma electrode (31), -900 V in the suppressor electrode (32), 0 V in the ground electrode (33), 30 kV in the focusing electrode (34) and -150 kV in the target electrode (35). The profile of equipotential lines is shown in Figure 14.

[0077] As a result of the simulation, Figure 15 shows the energy profile of the deuteron beams, representing their trajectories towards the target. The configuration presented allowed to reach a current of 198.5 mA of deuterons in the target.

Example 2: Assessment of neutron surge on target

[0078] The calculation of the neutron efficiency y was evaluated through equation 1. The values of the braking power were obtained through the Srim code. The adopted CLFTI of 6 openings in the plasma electrodes reached a neutron yield of 1012 n s’1.

Example 3: Neutronic assessment of the CLFTI

[0079] As an example of nuclear evaluation, a model of the CLFTI was built, simulated in the MCNP5 code (Monte Cario N-Particle). The materials used in this evaluation were: dry air (external environment), shielding (of boron polyethylene, density of 1.12 g.cm'3), reflector (of chrome, density 10.27 g.cm'3), receptacles ( stainless steel, density 8.0 g.cm'3), insulator (from kaolinite, 2.50 g.cm'3), plasma chamber filled with deuterium gas (density 0.01 g.cm'3) , plasma and target electrodes (copper, density 8.50 g.cm'3), acceleration environment with deuterium gas (from 0.001 g.cm3), target (copper, titanium deuterium, 8.50 g.cm'). 3), reflector (alloy of bismuth and lead, density 10.27 g.cm'3), and moderator (graphite, 1.70 g.cm'3, and light water, 1.0 g.cm'3). As a source of neutrons, the surge evaluated in Example 2, distributed in the target, was adopted.

[0080] The neutron flux in the moderator was generated in the simulation with code MCNP5, which performed the neutron transport in the moderator of CLFTI, whose fast energies, 2.45 MeV, reach the thermal range in the moderator volume.

[0081] Figure 8 shows the neutron flux spectrum (normalized as a function of the incident neutrons of the target) in the center of the moderator. It is observed that in the center of the moderator, the amount of fast neutrons, of 2.5 MeV, significantly decreases and the amount of thermalized neutrons, <0.1 eV, increases. The spectrum emitted by the target is monoenergetic at 2.5 MeV, not shown in the graph. This change in the neutron spectrum helps to increase the transmutation rate of the isotopes of interest.

[0082] Figure 9 presents the cross-section for d-d and d-t reactions that produce neutrons.

Example 4: Activity Assessment of Radioactive Iridium Samples

[0083] The lr-192 has a half-life of 74.2 days, decays by beta and gamma emission to a stable isotope, Pt-192. The beta rays emitted present energy in the range of 530 keV to 670 keV, the average of their emitted gamma rays is equivalent to 370 keV. Iridium-191 has a high thermal absorption shock section for neutrons (910 barns).

Iridium alloys in the form of wires for implants in brachytherapy can be produced. Consider the nuclide lr-191, with an isotopic abundance of 37.3%, in a platinum-iridium alloy (40% Ir / 60% Pt), with a mass density of 22.00 g.cm3, in the form of 0.2 wires cm in diameter, and 1 cm in length, for example. The atomic density of the Z nuclide to be transmuted will be 1.1590 1021 at.cm3. The yarn volume is 0.031415 cm3. So we have 3.6411,1019 atoms of lr-191.

[0085] The results of the temporal and volumetric transmutation rate Rv for the samples of Iridium-191, transmuting into lr-192, by radioactive capture reactions (n,g) can be calculated by equations 3 and 4.

[0086] In this case, the term (<oz(E)Φ(E,r)>/y) evaluated in the MCNP code, based on a geometric model of CLFTI, reached the value of 3.01329 1/cm2- b (using the ENDF-B.8 cross section library 77191.66c, where b= barn), in units of neutron emitted at the target, in the position of highest reaction rate, on the axial axis, and inside the moderator receptacle .

[0087] In this case, Rv (eq.3) is 0.0034925 Ir192 nuclides per cm3 per second, per target yield unit; or 1,09717.10‘4 nuclides of lr-192 produced per second in the source's neutron-activated wire. Considering a surge of 1012 n.s'1, we will have 110 MBq or 3.0 mCi per wire. This activity is achieved after 100 days of operation. Hundreds of iridium threads can be produced during this period, meeting the entire hospital demand of cancer patients.

Claims (3)

1) FUSER CELL, characterized in that it comprises a plasma chamber (38), cylindrical in shape, with a radius between 2 to 100 cm and a length between 3 and 30 cm and internal (46) or external (45) radio frequency (RF) antennas ; an arrangement of electrodes along the axial axis, where a plasma electrode (31) is arranged, in cylindrical shape, with a radius of 2 to 100 cm, with 1 to 100 openings per square centimeter, so that these openings have radii between 0.1 and 10 mm and thickness between 0.2 and 5 cm; a suppressor electrode (32), in cylindrical shape, with a radius of 2 to 100 cm and a thickness between 0.2 and 1 cm, positioned 0.4 to 4 cm from the plasma electrode; a ground electrode (33), in cylindrical shape, with a radius of 2 to 100 cm, thickness between 0.2 and 1 cm, positioned 0.9 to 4 cm from the plasma electrode; and the plasma electrodes (31), suppressor (32), grounded (33) maintain the same number of openings and dimensions, each opening may have a cylindrical shape, or cone or sphere trunk with radii between 0.1 to 10 mm; a focusing electrode (34), in the form of a cylinder, with a length of 1 to 5 cm, with an opening in the shape of a frustum of cone, with a smaller radius between 1 and 100 cm and larger between 3 and 100 cm, positioned from 1 to 12 cm from the plasma electrode; a target electrode (35), in cylindrical shape with a radius between 2 and 100 cm and a thickness between 0.1 and 2 cm, positioned 4 to 20 cm from the plasma electrode, the target being covered with metal hydride on the face exposed to the beam , capable of incorporating deuterium or tritium; target isolator and refrigeration system (48) with circulating internal refrigerant; the moderator receptacle (40) , in cylindrical shape with a radius ranging between 2 and 100 cm and length between 4 and 80 cm, adjustable, filled with a low molecular weight substance, called moderator (36); one or more sample receptacles (37), in cylindrical shape with a radius ranging between 2 and 10 cm and a length between 2 and 50 cm; surrounded by a neutron reflector (41) and a shield (44), with a thickness ranging from 1 to 80 cm; the target (35) consists of a metal hydride film, which is preferably titanium-deuterium (TiDx), where x varies from 0.1 to 6, deposited on the target's metal electrode plate; the refrigeration system (52) is composed of the heat exchanger and circulation pump; the refrigerant fluid (48) consists of mineral or organic oil; the electrodes (31), (32), (33), (34) and (35) are made of copper, aluminum, silver, gold, titanium, or their metallic alloy; the electrical insulators (39) are made of electrical insulating material, which can cover the unexposed face of the target electrode, the joints and edges of the electrodes, as well as at the entrances of high voltage electrical connections, between these conductive materials and other parts of the device, made of dielectric material such as glasses, special insulating ceramics or rubber; by the moderator (36) which is a casing that can be filled with one or more substances of low molecular weight and reduced neutron absorption, such as light water (H2O), heavy water (D2O), graphite, high density polymers, polyethylene, teflon, beryllium compounds or mixtures thereof; by the metallic reflector (41), preferably of chromium, copper, bismuth, lead, tungsten carbide or alloys or mixtures thereof; by the shield (43) and (44), composed of polyethylene, water, or graphite, mixed with a neutron absorber, such as boron or lithium based substances, and coated with bismuth, lead, or tungsten carbide; by the gas (53) that fills the plasma chamber (38) which is either neutral deuterium, or enriched with gaseous tritium. 2) FUSER CELL, according to claim 1, characterized in that the moderator casing (40) and the sample receptacle (37) can constitute a single element, so that the target nuclides can be inserted and combined in the moderator. 3) FUSER CELL, according to claims 1 and 2, characterized by connecting to a radio frequency power system - RF (50), to a high voltage system (51) with power connections for the electrodes (56) , and to a deuterium gas supply system (D2) (53) and (54).

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