The method of selection of the radionuclide carbon -14 from neutron-irradiated aluminum nitride
(57) Abstract:Usage: in Radiokhimiya upon receipt of the radionuclide carbon - 14. The inventive method consists in a preliminary heat treatment of the target material (AlN) in a stream of oxygen at a temperature of 800-850oC for 5 to 30 hours to remove impurities of carbon-12, the irradiation of aluminium nitride in the neutron flux and, finally, the annealing of the irradiated material in an atmosphere of oxygen at a temperature 920-1180oC for 1 to 5 hours to extract from him radionuclide carbon-14. The method can reduce the duration of heat treatment of irradiated aluminum nitride, as well as an increase in the specific radioactivity of the final product. table 2. The invention relates to the field of radiochemistry and can be used in the production of the radionuclide carbon-14, which is widely used for the synthesis of labeled compounds.A method of obtaining carbon-14 from neutron-irradiated aluminum nitride, whereby fine powder of AlN is first heated in a stream of oxygen for 30 min to a temperature of 600-700oC, and then increase the temperature to 900oC and support it to the full oxide is produced by the material, due to the fact that at 900oC the oxidation process of aluminum nitride is quite slow, in addition, this method can not be used when working with piketirovany irradiated aluminum nitride.Closest to the claimed method is the extraction of carbon-14 from neutron-irradiated aluminum nitride, namely, that of AlN after irradiation in the form of powder or pellets are heated in a stream of oxygen at a temperature 920-1180oC for 5 h /2/. When loading of aluminium nitride in a microwave reactor in powder form is almost complete burnout of the target product. However, when loading AlN in the form of tablets under the same conditions, the degree of extraction of carbon-14 is only 50% it Should be noted that this method does not allow to obtain the carbon-14 good quality, as contained in the original aluminum nitride stable isotope carbon-12 after irradiation and subsequent heat treatment in a stream of oxygen is also provided in the form of carbon dioxide and polluting the target of the drug, reducing its specific radioactivity.An object of the invention is the increase in the specific radioactivity of carbon-14 to be extracted from the SS="ptx2">This task is solved in that the original aluminum nitride before irradiation is subjected to heat treatment in a stream of oxygen at a temperature between 800 and 950oC for 5-30 hours Proposed processing mode allows you to virtually eliminate carbon-12 from the original target of the drug. Thus the oxidation of aluminum nitride practically does not occur, i.e., the nitrogen content therein remains unchanged. Subsequent processes reactor processing and oxidative roasting allows to obtain the product of carbon-14 higher specific radioactivity.Comparison with the prototype shows that this method of obtaining a radionuclide carbon-14 from irradiated aluminum nitride by thermal oxidation in a stream of oxygen differs in that the aluminum nitride before irradiation pre-cleaned the stable carbon-12 at a temperature below the oxidation of AlN. In addition, when using this method achieves a more complete extraction of the target component from irradiated aluminum nitride.Example 1. 50 g of the powder of aluminum nitride with the original carbon-12 in it to 0.33 wt. irradiated 121 day in the neutron flux 5,951013neutrons/cm2oC for 1 h was achieved almost complete recovery of carbon-14, which is in the form of dioxide is absorbed by a solution of barium hydroxide. The resulting barium carbonate had a specific radioactivity of 0.32 CI/g of carbon (1,181010Bq/g).Example 2. 50 g of the same powder of aluminum nitride as in example 1 before irradiation was heated in a stream of oxygen for 5 hours at a temperature of 800oC. the content of carbon-12 in it decreased to 0.16 wt. After irradiation and heat treatment on the above modes (example 1), the specific radioactivity of the preparation of carbon-14 was 0.61 CI/g of carbon (2,331010Bq/g), i.e., increased 1.9 times.Other examples are given in table. 1 (consumption of oxygen in the examples in table experiments was the same and amounted to 40-50 l/h).Note,
1. When the temperature 90050oC cleanse AlN from carbon-12 is inefficient, since the aluminum nitride begins to be oxidized to aluminum oxide, thus reducing the proportion of the target element nitrogen, which is formed of carbon-14 when irradiated AlN in the neutron flux.2. In the last column of the table. given the relative is counter-intuitive characteristic of the same drug (Aoextracted from neutron-irradiated AlN, not subjected to pre-treatment (example 1).During the cleaning of aluminum nitride from carbon-12 less than 5 hours, the specific radioactivity emitted carbon-14 has increased slightly. Increase cleaning time in excess of 30 hours does not give a positive effect.In addition, in the allocation of carbon-14 from tablets irradiated aluminum nitride proposed method achieved almost complete removal of the target product, while similar to the characteristic shown in the prototype, reaches only 50%
As can be seen from the table. in the time range 5-30 h a significant increase in the specific radioactivity of selected carbon-14 regardless of the form in which the aluminum nitride loaded into an oven (powder or tablets). You get a final product that has 2-3 times higher specific activity than when using as a target AlN, not subjected to a preliminary heat treatment in a stream of oxygen.In table. 2 shows data on the burning of carbon-14 from both powder and tablets irradiated aluminum nitride contained in the prototype, as well as obtained using PvE pressing and pre-sintering of the pellets in both cases the same.Are given in table. 2 evidence suggests that, compared with the prototype of the proposed method allows to increase the degree of extraction of the target product. The method of selection of the radionuclide carbon-14 from neutron-irradiated aluminum nitride, which consists in heating the irradiated aluminum nitride in the form of powder or pellets in a stream of oxygen at 920 1180oC for 1 to 5 hours, wherein the aluminum nitride before irradiation is subjected to heat treatment in a stream of oxygen at 800 850oC for 5 to 30 hours
FIELD: radio-chemistry; methods of production of the chromatographic generator of technetium-99m from the irradiated by neutrons molybdenum-98.
SUBSTANCE: the invention is pertaining to the field of the radio-chemistry, in particular, to the methods of production of technetium-99m for medicine. Determine the specific activity of the molybdenum and the sorptive capacity of the used aluminum oxide in molybdate-ions. The mass of the molybdenum necessary for production of the preset activity of the eluate of technetium-99m determine from the ratio:ATc= 0.867·L·m ln (m)/ln(mox·Wi), where:ATc - activity of the eluate of technetium-99m, Ki; L - the specific activity of molybdenum, Ki/g; m - mass of molybdenum, g;mox - the mass of aluminum oxide in the chromatograph column, g; Wi - the sorptive capacity of the used aluminum oxide in molybdate-ions, g/g. After making of corresponding calculations the solution of molybdenum is applied on the aluminum oxide. The technical result of the invention consists in production of the generator with the required activity of technetium-99m at usage of the minimum quantity of molybdenic raw.
EFFECT: the invention ensures production of the generator with the required activity of technetium-99m at usage of the minimum quantity of molybdenic raw.
1 ex, 2 tbl, 1 dwg
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
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
SUBSTANCE: invention concerns manufacturing of radionuclides for industry, science, nuclear medicine, especially radioimmunotherapy. Particularly it concerns method of receiving actinium -227 and thorium -228 from treated by neutrons in reactor radium-226. Method includes irradiation of target containing of metallic capsule in which there is located reaction vessel, containing radium-226 in the form of compound. Then it is implemented unsealing of target's metallic capsule, dissolving of received radium. From solution it is separated by means of precipitation, and then it is implemented regeneration, preparation to new irradiation and extraction of actinium-227 and thorium-228 from solution. At that irradiation, dissolving, radium separation, its regeneration and preparation to new irradiation are implemented in the form of its united chemical form - radium bromide, in the same reaction vessel made of platinum. Method provides reusing of the same platinum vessel for receiving of actinium-227 and thorium-228 from one portion of radium by recycling of irradiation and extraction in the same vessel. Separation of metallic capsule by means of dissolving provides saving of mechanical integrity of platinum reaction vessel for each new irradiation cycle and extraction.
EFFECT: increasing of radiationally-environmental safety of process, excluding operations of increased radiation hazard.
2 cl, 2 ex
SUBSTANCE: limiting specific weight of acid mL A, required for complete termination of its reaction with aluminium oxide is determined. The amount of acid mHCl required for treating aluminium oxide with mass mox is calculated using the relationship: mHCl=mL A·mOX. After making the corresponding calculations, aluminium oxide is treated with acid, put into a chromatographic column and a molybdenum solution is added.
EFFECT: more reliable operation of a technetium-99m generator in terms of prevention molybdenum from falling into the eluate owing to achieving maximum sorption capacity of the oxide used.
3 dwg, 1 ex
SUBSTANCE: method of making a chromatographic technetium-99m generator from neutron-irradiated molybdenum-98 involves depositing a predetermined mass of molybdenum into a chromatographic column with aluminium oxide. For this purpose, eluate output of technetium-99m from the generators with different adsorbed molybdenum mass is determined. Through extrapolation from the obtained calibration curve, the mass of molybdenum which corresponds to maximum output of technetium-99m from the generator Be=1 is found as mi=exp[(1-a)/b], where a and b are coefficients of the calibration curve Bi=a+b·ln mi, where Bi is the eluate output of technetium-99m from the generator for the adsorbed mass of molybdenum mi.
EFFECT: obtaining a generator based on neutron-irradiated molybdenum-98 with a narrow eluate profile for extracting technetium-99m.
1 cl, 3 dwg
SUBSTANCE: method for neutron doping of a substance involves slowing down fast source neutrons with a retarder substance, forming a stream of slow neutrons in a selected region and irradiating the substance to be doped with the slow neutrons. During the slowing down process, the fast source neutrons are separated according to propagation angles thereof; streams thereof moving a direction selected by the structure of the retarder substance are selected; streams selected by the structure are summed up, formed into a narrow band and directed onto the substance to be doped, which is controllably moved in the focal region of the neutron streams.
EFFECT: high efficiency of the doping process and forming regions with high degree of doping in given areas of the doped substance.
5 cl, 3 dwg, 3 ex
FIELD: physics, atomic power.
SUBSTANCE: invention relates to nuclear engineering, particularly to production of stable isotopes using neutron beams, and can be used in the electronic industry when producing semiconductor silicon structures using ion implantation techniques, as well as nuclear engineering when designing neutron retarding elements. The disclosed method includes making a starting target from a substance which contains a mixture of boron-10 and boron-11 isotopes, irradiating the target with neutron flux to the required or complete burn-off of the boron-10 isotope and extracting the 11B isotope from the substance.
EFFECT: obtaining boron and compounds thereof with high, more than 99,9%, enrichment on the 11B isotope and high degree of purity.
SUBSTANCE: invention relates to a method of producing radionuclides. The disclosed method includes irradiating a target medium containing at least a target nuclide material in a neutron radiation zone. Formation of radionuclides is carried out in the target radionuclide material as a result of irradiation, and at least some of the formed radionuclides are extracted from the target nuclide material. The extracted radionuclides are then captured and collected using carbon-based recoil particle capturing material which is free of an empty mesh structure at the crystallographic level.
EFFECT: obtaining radionuclides with high specific activity and soft radiation using the Szilard-Chalmers effect.
16 cl, 4 tbl
SUBSTANCE: in the disclosed method, target material containing a starting nickel-62 isotope, is given the shape and function of a structural component of a nuclear reactor core and then loaded for irradiation in place of said element. After achieving a given degree of irradiation, the material is unloaded and initial and newly formed nickel isotopes are extracted during chemical treatment.
EFFECT: improved utilisation of neutrons without affecting the reactivity margin of the nuclear reactor.