The invention relates to the field of radiochemistry, in particular a process for the production of radioisotopes. The invention can be used in radiochemistry for the production of radioisotopes silver with a high degree of purity.

To date, identified 33 of the radioisotope silver [1] (not including isomers) (M.S. Antony Nuclide Chart 2002, IReS, 23 rue du Loess, BP 20, Strasburg, France, p.15-16). Most of them have a small half-lives T_1/2- from milliseconds to several hours. 2-deficient radioisotope with atomic numbers And equal to 105 and 106, and 2 neutron-rich nuclide with A=110 and 111 are characterized by large values of T_1/2(more days). They are widely used in physical chemistry and electrochemistry (M. Haissinsky, Adioff J.-P. Radiochemical Survey of the Elements, Elsevier Publishing Company, Amsterdam/London/New York, 1965, p.143).

A method of obtaining a short-lived radioisotopes silver (Bruechle W., Herrmann G. Decay properties neutron-rich silver isotopes. Radiochim. Acta, 1982, Vol.30, No. 1, pp.1-10), formed during irradiation of natural uranium by neutrons with energy of 14 MeV, the irradiation²⁵²Cf thermal neutrons and cadmium neutrons with energy of 14 MeV (similar). After exposure to nitric acid solutions of uranium and cadmium was added a saturated solution of K₂Cr₂About₇in a 2N solution of N₂SO₄then the resulting solution was passed through a thin layer of AgCl, which was carried out accumulation is radioisotope silver. The resulting digest was washed, dissolved, filtered and held it γspectrometry (manually or automatically) on the content of radioisotopes silver. The disadvantages of the method are its complexity and the complexity of the technological cycles.

The described method of producing radioisotopes silver without media (Eichler B., Domanov VP Preprint JINR, P 12-7775, Dubna, 1974), which emit in the form of chlorides (prototype). According to the proposed approach, as the target material using metal cadmium, which is irradiated with accelerated protons with an energy of 660 MeV. In the irradiation process, the target substance is accumulated neutron-deficient isotopes of silver, in particular¹⁰⁵Ag¹⁰⁶Ag, produced by nuclear reactions of Cd(p,2pxn), and related nuclides with atomic numbers Z<47. The irradiated material is transferred onto the surface of quartz sand, placed in a quartz tube, and heated distilled target substance in a stream of hydrogen, and quartz sand with adsorbed on its surface the products of nuclear reactions are placed in the starting zone of the quartz tube (TCA), which is heated at 1000°in a stream of chlorine gas carrier and reagent. The resulting volatile chlorides adsorbed on the walls of TCA at certain temperatures. In the described conditions, silver chloride (AgCl) wasp is given at 620° C.

The disadvantages of the method include the presence of radioactive preparations of silver radioisotopes rhodium and palladium, as the volatility of their chlorides close to the volatility of silver chloride.

The technical task of the present invention to provide a radioisotope silver with high radiochemical purity.

This object is achieved in that the selection of radioisotopes silver as a reagent used a couple of phosphorus or arsenic. In the first case, the silver forms a volatile phosphide, which is deposited on the quartz surface at 660-680°and the second volatile gallium, adsorbiruya at 620-640°C. Co silver isotopes with Z<47, in particular, palladium, rhodium, ruthenium, technetium, niobium, zirconium, and yttrium, volatile compounds do not form and they remain in the original sample.

The essential difference between the proposed method from the prototype is that the quality of the reactant gases used a couple of phosphorus or arsenic.

This significant feature allows you to get radioisotopes silver with a high degree of purification from impurities.

The method consists in the following: cadmium target is irradiated with accelerated protons. When irradiated cadmium radioisotopes are formed with Z≤48, in particular¹⁰⁶Ag(T_1/2=8,3 day) and¹⁰⁵Ag(T_1/2=41,3 day). After irradiation emesto target is transferred onto the surface of quartz sand, placed in a quartz tube, and in a stream of hydrogen is stripped off the target substance heated to a certain temperature. After distillation and cooling heating zone quartz sand collected on the surface of radioisotopes is transferred into the starting zone of quartz TCA, before which is placed a solid reagent is phosphorus or arsenic. Ready to experiment column mounted inside a cascade of tubular furnaces having different functional purpose. The first furnace (1) is intended for heating of a solid reagent to a certain temperature, the second (2) provides hot vapor transport of the reagent, the third (3) heats the source of the radioactive sample to a high temperature, and the fourth (4) creates along column a negative temperature gradient. After purging the installation purified helium along the column set specified temperature distribution. In the process of high-temperature chemical processing of the original sample pairs reagent radioisotopes silver form volatile pnictide transported along TCA in a stream of helium and adsorbiruyuschee at certain temperatures. Radioisotopes associated with silver elements volatile compounds do not form and remain in the original sample. The main share of gaseous reagents that have not entered into a chemical reaction is deposited on the walls of the TX is at comparatively low temperatures. Distribution^105,106Ag along TCA and their chemical output Y is determined using γspectrometer. The value of Y depends on a number of parameters, in particular on the concentration of the reactants in the gas phase, which, in turn, is determined by the temperature of heating of a solid reagent t₁. When working with red phosphorus and heated to 320°C, the value of Y was 43%, with t₁=330°C is Y=65%and t₁=340°C the value of Y reaches 76%. Heating of the phosphorus at higher temperatures leads to a noticeable increase in the concentration of vapors, which precipitated override column. Thus, the temperature range of 330 to 340°is optimal to implement the method.

When choosing a concentration in the gas phase arsenic data was used (Tables of physical quantities. Handbook edited Ikkicon, M., Atomizdat, 1976, s). It is found that upon heating of the reagent to 370°With the value of Y was 51%. At t₁=390°C chemical release of radioisotopes silver rose to 75%, with t₁=405° - Y=87%, and at t₁=415°C is Y=84%. Based on the obtained data, it was concluded that the temperature interval 395-415°C is optimal for the given problem. Translation of selected radioisotopes in the aqueous phase is carried out by processing zone adsorption pnictides a suitable solvent is, for example nitric acid.

Example 1

The proposed method was used to obtain ultrapure preparations isotopes¹⁰⁶Ag(T_1/2=8,3 day) and¹⁰⁵Ag(T_1/2=41,3 day). 8 g of granulated cadmium brand OSC irradiated with accelerated protons with an energy of 660 MeV and beam intensity of 5×10¹²with^-1. cm^-2within 72 hours. At the end of the irradiation target "cool" in 2-3 days, transfer it onto the surface of quartz sand (d=100-200 μm), previously placed in a quartz tube (d=10 mm), and distilled the target substance in a stream of hydrogen at a temperature of 600°C. after sublimation and cooling device received the original radioactive sample is transferred into the starting zone of quartz TCA (d=3 mm), and at the beginning of the column is placed a solid reagent red phosphorus brand OSC Prepared column placed inside a cascade of tubular furnaces. After purging the column in a stream of purified helium (residual water vapor content of less than 10^-4% and oxygen of less than 10^-6%) consistently applied voltage on the furnace (4), providing a negative temperature gradient with value α=-17°/cm), oven (2) (360-380°C), then furnace heating source of the sample (3) at 900°C. Upon reaching the specified parameters were applied voltage on the furnace (1), in which phosphorus was heated at 340°C. the Concentration of p is the moat phosphorus was equal to 4× 10^-6mol·cm^-3. The volumetric rate of helium was 20·cm³·min^-1and the duration is 1 hour. The resulting phosphide silver was deposited at 680°With chemical yield of 75%. Radiochemical purity of the preparations of radioactive silver amounted to 99.99%. The result is illustrated in figure 1, which shows the distribution of phosphide^105,106Ag along the column. It is seen that the zone of deposition phosphide silver and phosphorus separated, which shows the high chemical purity of the selected radioisotopes silver.

Example 2

Ultrapure preparations radioisotopes¹⁰⁶Ag(T_1/2=8,3 d) obtained when using as the reagent vapors of arsenic. 6.5 g of granulated cadmium brand OSC irradiated with accelerated protons with an energy of 660 MeV and beam intensity of 7×10¹²with^-1·cm^-2within 48 hours. At the end of the irradiation target "cool" in 2-3 days, transfer it onto the surface of quartz sand (d=100-200 μm), previously placed in a quartz tube (d=10 mm), and distilled the target substance in a stream of hydrogen at a temperature of 600°C. after sublimation and cooling device received the original radioactive sample is transferred into the starting zone of quartz TCA (d=3 mm), and at the beginning of the column is placed a solid reagent arsenic brand HTC,which was preliminarily purified by vacuum sublimation. Then the column is placed inside a tubular furnace (1)to(4). After purging the column in a stream of purified helium (residual water vapor content of less than 10^-4% and oxygen of less than 10^-6%) consistently applied voltage on the furnace (4), providing a negative temperature gradient with value α=-17°/cm), oven (2) (430-450°C), then furnace heating source of the sample (3) (900°). Upon reaching the specified parameters were applied voltage on the furnace (1), in which the arsenic was heated at 405°C. the vapor Concentration of arsenic was 2×10^-6mol·cm^-3. The volumetric rate of helium was 20 cm³· min^-1and the duration is 1 hour. The obtained gallium silver was deposited at 640°With chemical yield of 87%. Radiochemical purity of the preparations of radioactive silver was also 99,99%. Figure 2 shows the distribution of gallium silver along the column. Figure 2 shows that the zone of deposition of gallium, silver and arsenic are at a considerable distance from each other, which ensures high chemical purity of the obtained radioisotopes silver.

The proposed method can be used both in traditional applications, electrochemistry, physical chemistry)and chemical identification of superheavy element with Z=111 - estimated khimicheskogo the analogue of silver and gold.

The method of producing radioisotopes silver without media, namely, that as the target material using metal cadmium, which is irradiated by high energy protons, separate the target substance by sublimation in a hydrogen atmosphere, collecting the products of nuclear reactions and transformations on the surface of quartz sand, placed received radioactive sample in the starting zone quartz thermochromatographic column, hold its high-temperature chemical processing in the presence of the reagent with the implementation of transport of the formed volatile compounds and their subsequent deposition on the walls of TCA at certain temperatures, characterized in that the reagent is used a couple of phosphorus or arsenic.