Use of accelerators in geology, medicine, isotopes production and atomic power energetics

Some examples of using of nuclear-physical methods in contiguous domains are presented.

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Опубліковано в: :Вопросы атомной науки и техники
Дата:2001
Автори: Dikiy, N.P., Dovbnya, A.N., Uvarov, V.L., Khazhmuradov, М.A., Shramenko, B.I.
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Мова:Англійська
Опубліковано: Національний науковий центр «Харківський фізико-технічний інститут» НАН України 2001
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Цитувати:Use of accelerators in geology, medicine, isotopes production and atomic power energetics / N.P. Dikiy, А.N. Dovbnya, V.L. Uvarov, М.А. Khazhmuradov, B.I. Shramenko // Вопросы атомной науки и техники. — 2001. — № 1. — С. 26-35. — Бібліогр.: 11 назв. — англ.

Репозитарії

Digital Library of Periodicals of National Academy of Sciences of Ukraine
_version_ 1860262594875490304
author Dikiy, N.P.
Dovbnya, A.N.
Uvarov, V.L.
Khazhmuradov, М.A.
Shramenko, B.I.
author_facet Dikiy, N.P.
Dovbnya, A.N.
Uvarov, V.L.
Khazhmuradov, М.A.
Shramenko, B.I.
citation_txt Use of accelerators in geology, medicine, isotopes production and atomic power energetics / N.P. Dikiy, А.N. Dovbnya, V.L. Uvarov, М.А. Khazhmuradov, B.I. Shramenko // Вопросы атомной науки и техники. — 2001. — № 1. — С. 26-35. — Бібліогр.: 11 назв. — англ.
collection DSpace DC
container_title Вопросы атомной науки и техники
description Some examples of using of nuclear-physical methods in contiguous domains are presented.
first_indexed 2025-12-07T18:57:04Z
format Article
fulltext USE OF ACCELERATORS IN GEOLOGY, MEDICINE, ISOTOPES PRODUCTION AND ATOMIC POWER ENERGETICS N.P. Dikiy, А.N. Dovbnya, N.A. Skakun, V.L. Uvarov, М.А. Khazhmuradov, B.I. Shramenko National Science Center “Kharkov Institute of Physics and Technology”, Kharkov, Ukraine Some examples of using of nuclear-physical methods in contiguous domains are presented. PACS: 28.41.Kw. 1. ANALYSIS OF NOBLE METALS Use of powerful accelerators for analysis of noble metals in ores allows performing mass analysis on rep- resentative trials with a threshold of detectability 0.03 - 1 g/t without preliminary concentration. Herewith one realizes high technical-and-economic characteristics (for example, cost of element determination is in 2- 3 times lower than for the assay). A peculiarity of the method offered is the use of directed activity with large (more than 5 days) half-life, that allows to obtain a threshold of detectability of about 0,3 g/t for Ir, Au, Ru, Rh. Oxides and silicates Al, Fe, Ca, Na, I, Mg make up almost 99 % of ores of the earth-crust. On isotopes of these metals, and also O and Si only activities with de- cay periods less 2 days are induced. Activities on Al and Na have more long half-life (7.38 105 and 2.6 year, re- spectively) and are characterized by a low cross-section of (γ,n)-reactions. The authors have studied the samples of ores from diverse Ukraine’s deposits. Irradiation was performed by bremsstrahlung radiation of electrons with energy of 16-25 МeV. A mean electron current was from 100 to 1 mA, irradiation time from 1 hour to sever- al days. The counts of bremsstrahlung radiation absorp- tion in samples under investigation was carried out by irradiation of standards with a known amount of the ele- ment being determined and consequent measuring the sought activity in them. The gamma-radiation registra- tion was conducted with a Ge(Li)-detector having an en- ergy resolution of 1,9 keV on the 1333 keV line. To decrease the background radiation a detector was placed in the leaden container with a shielding thickness of 5 cm, that allowed to decrease a background in the range of 100-500 keV approximately in 5 times. An element ore composition was determined after mathematical processing of spectra obtained. To do this at first the smoothing of apparatus spectra by Laplace- Gauss filter was made with taking into account the prior information on the width of peaks registered [1]. Here- inafter, using the fast algorithms to solute the set of lin- ear equations for concentrations to be determined with addition of background value by the minimization method, we calculated the search content. For calibra- tion we used the standard spectra from samples with a known content of elements analyzed. A typical spec- trum of induced activity of the ore sample is shown in Fig. 1. For Аu analysis the activity of 196Au (T1/2=6.8 days) was used by measuring gamma-lines with energy of 426, 355.7 and 333 keV. The high cross- section of the 197Au(γ,n)196Au reaction allows to achieve a threshold of detectability 0,03-0,1 g/t for majority of ores excluding manganese. Industrial manganese con- tent in ores (more than 10%) lowers a threshold of de- tectability of gold to 1-1,5 g/t (due to the intensive 54Mn line with E = 834.8 keV). 1000 1200 1400 channels 1 10 100 1000 co un ts ju vl Os Ir IrIr Os Fig. 1. Spectrum of a sample from ores with Os Determining of the Ir content was conducted by reg- istration of the activity of 190Ir (T1/2=12.1 day) and 192Ir (T1/2=74 days). For analytic determining Ir as a result of the higher intensity of decay a more preferable is 190Ir (analytic line with E=371, 407, 518, 558, 568, 605 keV). In the case of high background radiation loading and interference from other elements it is possi- ble to use the 192Ir activity (analytic lines of 308, 316, 468 keV). Then a threshold of detectability for above mentioned irradiation conditions on 190Ir is 0.5 g/t. Determination of Ru content was realized using the induced activity of 103Ru (T1/2=207 days). The radiation with E=497 and 610 keV was detected. A threshold of detectability in this case is 0.8 g/t. When using the ac- tivity of isotope 103Ru one should take into account the interference from 131Ва (gamma-radiation with an ener- gy of 496.2 keV). In spite of a low Ba content in Ukraine’s ores and low abundance of 132Ва, that is 0.097 %, the activity from Ru and Ba has the compara- ble values. Therefore for a reliable analysis we had to measure the activities of 131Ва and 103Ru in time with consequent numeral account of 131Ва in 497 keV line in- tensity. The Rh content was measured by registration of in- duced activity of isotope 102Rh (T1/2 =207 days). The gamma-line with an energy of 475, 557, 628, 1103 keV was detected. A threshold of detectability was 1.8 g/t for given irradiation conditions. 26 PROBLEMS OF ATOMIC SCIENCE AND TECHNOLOGY. 2001, № 1. Series: Nuclear Physics Investigations (37), p. 26-35. The Os content was measured using the activity of 191Os (Т1/2=15.4 days). The radiation with energy of 129.4 keV was registered. Due to the interference from thorium-232, which always exists in surrounding con- structions, a threshold of detectability is 2-8 g/t. A simi- lar threshold of detectability is realized also in the case of using the reaction 196Os(γ,n)195Os and measuring the activity of 195Os (T1/2=94 days). (It is the most intensive 646.1 keV gamma-radiation line.) On Pt induced is the activity in the reaction 195Pt(γ, γ')195mPt, that allows to determine the Pt content at a lev- el of 0.3 g/t. So, at powerful linear accelerators of NSC KIPT we realized the gamma-activation analysis of simultaneous determining the group of noble metals in representative trials of ores with a threshold of detectability 0,03-3 g/t of a high economic effectiveness, that is particularly necessary when testing ores with noble metals at de- posits under mining or introduced in production [2-6]. Advantage of the method described consists also in de- termining noble metals as well as elements-indicators (As, Tl and others). 2. RESEARCH OF DIFFUSION OF ACTINIDES IN GRANITES Working out the schemes for reliable disposal of NPP radioactive waste in geological structures is an im- portant factor of atomic energetic development in Ukraine. Use of powerful electron accelerators allows deciding successfully the problems concerning the choice of the area for RAW storage placing. Study of diffusion with RAW imitators was carried out as follows: a Yb2O3 standard was irradiated by bremsstrahlung radiation from 22 МeV linear electron accelerator (LEA). During irradiation observed was the activation of isotopes Yb: 175Yb (Т1/2=4.2 days), the most intensive line 396 keV and 169Yb (T1/2=30.7 days), the most intensive lines 198 keV and 177 keV. The weighed amount of Yb oxide (Yb2O3) in irradi- ated granite was 100 mg. The extracted Yb oxide was dissolved in 0,2 ml of concentrated HCl and reduced with deionized water to pH=1.8. The obtained YbCl3 volume of 40 ml was placed in a heat-resistant retort with a reverse cooler. Heating of the solution was per- formed in the water bath during 32 hours. After this the granite standards were washed with distilled water dur- ing 24 hours and dried out in a drying cabinet at 60°C. Skimming of layers from standards was conducted by the methods of precision grinding. The layer thickness of 1 µm was sufficient to study the diffusion in the stan- dard. To avoid losses of skimmed layers we performed wet grinding with the use of filtering and parchment lin- ers. The thickness of skimmed layers was from 2 to 100 µm, that made it possible to judge more exactly and reliably on the diffusion profile. The skimmed layers were packed and after their activity was measured with the Ge(Li)-detector. Measuring of the Yb radiation intensity was carried out during 20-30 min. Analysis of spectra was per- formed by standard programs of gamma-radiation spec- trum processing. The typical activity spectra of 169Yb are shown in Fig. 2. The thickness of the skimmed layer was 50 µm, therefore the gamma-lines from the granite matrix: 881 keV (84Rb), 1297 keV (47Ca) and others are well displayed. 400 800 1200 1600 channels 2 5 2 5 2 5 2 5 1 10 100 1000 co un ts 84 Ca47 Rb 511 keV Yb 169 ju vl Fig. 2. Typical granite spectrum of the granite layer ac- tivity (d = 50 µm, 3 Grad) 0 100 200 300 400 depth, m 0.01 0.10 1.00 10.00 co nc en tra tio n, * 10 at /c m 20 3 µ c b a ju vl Fig. 3. Concentration of 169Yb in some granite stan- dards (b - initial with pegmatite structure, c - initial uniformly grained, a - after irradiation with a dose of 3 Grad) The calibration measurements of radiation intensities enabled one to calculate the Yb concentration in gran- ite. Its maximum value at the surface of the standard ir- radiated by a dose 3 Grad was 3∗1020at/cm3. The results of measuring Yb profiles in granites for mentioned above conditions are given in Fig. 3. Visible are two typical ranges of values: 0 to 60 and 60 to 500 µ m. The first range conforms to diffusion into crystal- lites, which are in the composition of plagioclases. It should be note, that in the sample, exposed to irradia- tion to 3 Grad, the concentration dependence of Yb dif- fusion differs essentially from the analogous depen- dence for sample, not exposed to irradiation. The char- 27 acter of the curve for sample 3, corresponds to the diffu- sion along the grain boundary (in our case, evidently, by cracks, chips etc., which are detected by mineral - petro- graphic analysis). Note, that during irradiation cracking of feldspar crystals takes place. Analysis of samples 7 and 8 also shows diffusion through mentioned above de- fects; at the same time the volume diffusion into grains (crystallites) is observed. The values of the diffusion co- efficient in the first range are 3.2*10-11 (for 3), 1.4*10-11 (for 7) 1.09*10-11 (for 8). In the range of 60-500 µm the concentration depen- dencies for all sample have a similar character, and only the concentration values differ. In coordinates x6/5 they have a linear character. This confirms the dominance of diffusion in this area along the grain boundaries. And values of diffusion coefficients 2.2*10-8 (for 3), 6*10-9 (for 7) and 4.8*10-9 (for 8) сm2/с justify this fact. For the irradiated sample the diffusion along the grain boundaries exceeds in 1500 times the diffusion in crys- tals. Note, that in the irradiated standard the diffusion coefficient is higher as for crystals (grain modification), as well as for grain-boundary diffusion (probably, as petrographic analysis shows, this is conditioned by space of Na, Ca, K, Si). Probably in this case not classic diffusion on grain boundary is realized, but the diffu- sion with discontinuous Yb precipitation. In this con- nection the creation of artificial matrices should be done with providing the decrease of the grain-boundary mo- bility of Na, Ca, K and creation of conditions for sup- pressing the mentioned above processes at granite crys- tal boundaries. Like to the man-caused effect on granites, under ir- radiation the most essential role is played by the proc esses, which lead to formation of ions H+, OH–, CO3 2−, Na+, Ca2+ and their complex influence on the processes of boundary modifications, melting of cracks, diverse precipitations and, as a result, have influence on the RAW mass transfer. 3. ANALYSIS OF THE ELEMENT COMPOSITION OF CONSTRUCTION AND OTHER MATERIALS OF CHNPP 4 UNIT Using the methods of nuclear-physical, crystal-opti- cal analyses and infrared spectroscopy (IR spec- troscopy) the study was conducted on a phase composi- tion and structural transformation of core samples, se- lected when boring the cement wall of ChNPP 4 Unit. A typical concrete standards spectrum after irradia- tion on electronic accelerator brought on Fig. 4. After activation of the concrete core on powerful electron ac- celerator the concentrations of I, Ca, Ce, Mn, Sr, Cs, Na, Rb, Zr, Ni, Pb and other elements for diverse bed- ding depths were determined. 4. NUCLEAR-PHYSICAL METHODS FOR ANALYSES OF IODINE FILTERS IN THE PROCESS OF NPP OPERATION Use of powerful electron accelerators for analysis of element composition of iodine filters enables one to work out successfully the problem of their regeneration and further use in the systems of NPP throwaway clean- ing. In the present research the macro- and microelement composition of NPP iodine filters after decommission- ing was determined. For this the iodine filter was opened with a special sampler and the coal samples in three positions were taken. The coal cores taken from diverse depths were packed up by 5, 6, 7 g. Absolute values of element content were determined relatively to samples, which were irradiated together with the samples under study. We measured the activi- ties of isotopes obtained in reactions: 55Mn(n,γ)56Mn, 4 0 0 8 0 0 1 2 0 0 1 6 0 0 2 0 0 0 n u m b e r o f c h a n n e l s 1 0 1 0 0 1 0 0 0 1 0 0 0 0 n u m b e r o f r e a d i n g s S c 4 7 U 2 3 7 K 4 3 C a 4 7 5 1 1 K 4 3 C s 1 3 2 K 4 0 N i 5 7 N a 2 4 C a 4 7 N a 2 2 Z r 8 9 R b 8 4 M n 5 4 C a 4 7 j u v l Fig. 4. Gamma spectrum of the sample 133 after irradiation at LEA during 41 hours 28 0 400 800 1200 1600 2000 number of channels 2 5 2 5 2 5 2 5 1 10 100 1000 nu m be r o f r ea di ng s 511 Cl 34m Sc47 Ba135m Pb203 K 43 Sr +I12687m K 43 I126 Mn 56 Mn 54 Zr 89 Na 24 Ca 47 Ni 37 ju vl Fig. 5. Typical spectrum of coal filter activity after irradiation at the electron accelerator 0 . 6 0 . 8 1 . 0 c o n t e n t , r e l . u n i t s 0 1 0 2 0 3 0 d e p t h , c m S r 0 . 2 0 . 4 0 . 6 0 . 8 1 . 0 B a 2 0 3 0 4 0 c o n t e n t , g / g . I j u v l µ 0 1 0 2 0 3 0 d e p t h s , c m . 0 . 8 0 . 9 1 . 0 c o n t e n t , r e l . u n i t s . 0 . 7 0 . 8 0 . 9 1 . 0 S r j u v l Fig. 6. Content of a number of elements depending on the filter depth Fig. 7. Sr content depending on the filter depth in centre and at periphery 127I(γ,n)126I, 35Cl(γ,n)35mCl, 90Zr(γ,n)89Zr, 88Sr(γ,n)87mSr, 48Ca(γ ,n)47Ca→47Sc, 44Ca(γ,p)43K, 23Na(n,γ)24Na, 140Ce(γ,n)139Ce, 204Pb(γ,n)203Pb. A typical spectrum of induced activity is shown in Fig. 5. The content of measured elements in dependence on the depth of a core, taken at the filter pe- riphery, is given in Fig. 6. In the given position a turbu- lent behavior of the airflow was not observed. In Fig. 7 given is the strontium content depending on the depth for two cores: in center (turbulent behavior of the air flow) and at periphery (from one side, where laminar air flow behavior is observed). From Fig. 6 it can be seen, that the 127I content de- creases with the core depth. Note the typical distribution on depth by concentration of Ba, Sr, Zr, Ca. Peculiarity of their distribution is a maximum at 15 сm. The most considerable concentration increasing is observed for barium that is related to his high reaction capability. It is known, that Ba makes lightly oxides and nitrides. Also, it is capable to form lightly iodates (Ba(IO3)2) and io- dide (BaI2). The maximum concentration of above-mentioned el- ements in the filter middle, presumably, are conditioned by the influence of vapors of NO2, ClO, ClONO2 (chlo- rine nitrate), which are formed in air under radiation [7]. Radiation effect leads also to formation of acetic acid from methane, being contained in air (oxidation of СН4 with hydroxyl (ОН) → СН3 + О2 → СН3О2 + НО2 → СН3ООН). Acetic acid interacts with elements of the second group intensively. Nitrates, nitrides, hypoclorides, barium acetates and strontium or their complex compounds being formed can easy move on the filter, and as a result the dynamic distribution of these elements with a maximum in depth of 15 сm takes place. A practically permanent concentration of Mn, Ni, Na, Ce, Pb on the core depth is observed. Note, that PbI2 is one of the very steady iodine compounds. An in- significant entering of aerosols from the near- reactor space into iodine filters can hamper their reliable ex- ploitation. A typical spectrum of aerosols, deposited on the iodine filter grid, is represented in Fig. 8. It is obvi- ous, that the presence of 137Cs, 60Co, 110mAg, 54Mn con- forms to the typical composition of radioactive aerosols for the reactor being in operation. 29 0 400 800 1200 1600 2000 channels 1 10 100 1000 co un ts Co60 Co60 Ag 110m Ag +Cs137110m Cs134 511 Cs134 Ag110m Mn54 Ag 110m ju vl Fig. 8. Typical activity spectrum on the filter grid 5. USE OF ELECTROSTATIC ACCELERATORS IN RELATED FIELDS The electrostatic accelerators of NSC KIPT are used for solving the problems in the field of ecology and medicine [1,6,8]. Depending on the problem being solved one uses diverse nuclear-physical methods: Rutherford backscattering (RBS), promt radiation of nu- clear reactions (PRNR) and X-ray radiation (XRR) ex- cited by protons or multicharged ions of N and O. The given methods possess the most acceptable technical and economic characteristics when determining the ele- ment composition and impurity atom distributions in the sample depth. Choosing the energy and type of acceler- ated particles; one can control the threshold of de- tectability for definite groups of elements. X-ray radiation was registered with a spectrometer on base of a Si(Li)-detector with an energy resolution of 220 eV on the 5,9 keV line. An element composition of biological samples was determined after mathematical processing of spectra obtained. Herewith, for calibration the standard spectra from the samples with a known content of elements being analyzed were used. During element analysis a special attention was paid to the sample preparation that allows one to broader the possibilities of nuclear-physical methods used. To achieve at acceptable technical and economic character- istics, where possible, the sample in a natural form (hairs, nails, teeth, filters etc.) were used. To avoid the sample destruction in the process of measurements, a complex of actions on decreasing the current density of ions used and optimization of the X-ray spectrometer position were undertaken. The current density was 10 nA/сm2 for AFA filters and hairs. The dose was 3- 5 µCoul. A threshold of detectability depends on the atomic element number, e.g. for iron it is 10-7 g/g. If during measuring the required threshold of detectability (mainly for toxic elements: Hg, As, Cd, Pb) was not reached then the concentrating took place. More fre- quently it is the decomposition of the sample and mer- cury deposition in the form of clorides, lead - as sul- phates, cadmium - as sulphides. When it was necessary to measure the content of elements with a threshold of detectability of 10-10 g/g one conducted the sample de- composition with consequent electrolytic concentrating the element on the plate from graphite or other material. When analyzing the liquid samples (blood, serum, plasma) the dry and wet aching was performed. The formed mineralized the carrier was deposited layer by layer onto the plate. The calibration curves were ob- tained by the method of additions during the target preparation. Analysis of light elements (Na, F, C, N, Li, B, Mg, Al) was conducted with the use of PRNR. In this case γ-radiation, more rarely - charged particles and neutrons were detected. For example, when using the reaction 19F(p,αγ)16O a threshold of detectability of fluorine in teeth (this object allows a rather high intensity and pro- ton dose) was 10-7 g/g. For nitrogen being a basic ele- ment in the protein composition, a threshold of de- tectability limit was at a level of 10-5 g/g in the reaction 15F(p,αγ)12C. The lower thresholds of detectability of 10-5 g/g were obtained for B, Be, Na and for C, Li, Mg, Al it was by two order higher, 10-4 g/g. An essential property of nuclear reactions is a possi- bility to study the element distribution in biological samples in depth that is important diagnostics of some diseases. In the present given are the results of studying the effects of general and specific contaminations on evolu- tion and propagation of some cancer diseases (cancer light, skin cancer). In technological processes of many operating enter- prises one uses a raw materials containing toxic ele- ments. A toxicity of the element is conditioned by its chemical nature, amount and composition of the com- pound, in which it is, as well as by the method of enter- ing in the organism, and depends on the age, sex and in- dividual peculiarities of the organism. 30 0 2 4 6 8 10 12 length of service, years 1 3 5 7 9 C on te nt e le m en t, re l. no rm K S Ca Fe Ni Cu Mn Sr a ju vl Fig. 9. Element content in hairs of workers working in harmful conditions vs the length of service Man illnesses, caused by the presence of toxic ele- ments in air of the working zone, in raw materials, ready production, and consequently, in biological objects (hairs, nails, teeth, blood), in most cases are complicated by falling the activity of immune system. For example, it was established, that in first years (1-3) of workings at enterprises with harmful labour conditions a number of diseases of viral, bacterial and other etiology (mycosis, herpes, frequent respiratory diseases, flu) is observed in 42-60 % of workers, in consequent years one marks their smooth diminution. To 3-5 years a number of dy- namic diseases increase to 10-15 %, to 5-6 yeas it de- creases, and to 9-10 years it increases to 25 %. Such “undulating” character of a number of diseases is in cor- relation with content of some elements in hairs of per- sons working in harmful labour conditions. In Fig. 9 represented are the elements in hairs of workers de- pending on the length of service. The content of such el- ements as Zn, K, S, Ca during the observation period from one to ten years does not reveal significant devia- tion of these elements from the sample. The content of Mn, Fe, Cu, Ni has two maxims for years of servicing with a tendency to lower after 10-years length of ser- vice. The content of Sr in hairs rises in the first year of working, decreases during the second year and monotonously grows in consequent years. The above- mentioned “undulating” character of dependencies, pre- sumably, can testify of the degree of workers’ adapta- tion to harmful labour conditions. A similar dependence is not observed for workers the activity of which is not connected with harmful labour conditions. It should be also noted, that the percentage of morbidity by infec- tiously allergic forms is higher for men than for wom- en. Changes in the immunological status of workers and in the content of microelements at first bear a unspecific character. However, development of a subsequent im- munodeficit and lack of organism’s adaptation reaction on the influence of harmful production factors leads to beginning of a chronic form of morbidity (psoriasis, bronchial asthma), to disability and to development of cancer diseases. A statistics shows a high rate of the death from cancer diseases for people, retired on a pen- sion after work in harmful labour conditions. Analysis of results on the element content in raw materials, ready production and in air of the working zone testified the accordance of these values to maxi- mum permissible concentrations. Undoubtedly, this fact considerably complicates conducting the disease-pre- vention service and justifies the necessity of developing individual measures for everyone of working persons. The mathematical processing (correlation and re- gression analysis, function of distribution density proba- bility) of dependencies of general and specific contami- nations for 14 regions of Ukraine on propagation of can- cer diseases (cancer light, skin cancer out etc.) has shown, that actually there is not distinct linear depen- dence between the degree of contamination in that or another domain and the degree of cancer disease propa- gation. The character of these dependencies is more complicated, having also “undulating” nature, depend- ing on the sex, age, mechanisms of organism adaptation etc. So, the use of electrostatic accelerators for analysis of element composition of biological objects and objects of environment can be an effective control means, and also provides a high-productivity due to many-element factor, exactnesses and measuring sensitiveness. 6. DEVELOPMENTS AND USE OF DIRECT NUCLEAR- PHYSICAL METHODS To realize these opportunities the specialists of KIPT developed the methods, devised, constructed and put in service the installation with a goniometer having three degrees of freedom. They provided a possibility for si- multaneous registration of nuclear reaction radiation, backscattering particles and characteristic X-ray radia- tion, excited with accelerated particles. There were re- lized: automatic mode of angular crystal orientation rel- atively to the bunch pulse; search and identification of crystallographic directions, plane-parallel shift of targets relatively to the point of beam impinging the target; an- gular scanning; and registration of radiation yields with spectrometers. The goal of the works was studying the structure, composition and properties of ion-doped monocrys- talline single-element and binary quasi-conductors, magnetic materials, many-component compounds (in- cluding HTSC) and model structural metals. The results of these works served, in particular, as a base for development of a technology of infrared radia- tion devices (IR-devices). It is shown, that such devices can be made on the base of antimonide india doped with Be ions. The technology of basic structures of such de- vices is optimized. In Fig. 10 shown is the dependence of aγ-quantum yield of the reaction 9Ве(α,nγ)12С, 31 Fig. 10. Results of anglular scanning within main crystal axes of InSb, ion-doped Be, (•) - γ-quantum yield from the reaction 9Ве(α,n`γ)12С, (°) - backscat- tered α-particles. Dose of Be ions is 6⋅1014 cm-2, energy is 100 keV Fig. 11. Dependence of gamma-quantum yield from the reaction 13С(р,γ)14N and of back-scattered protons from the crystal Ni + 0,3 at.% 13C by anglular scanning in vicinity of crystallographic axis <110> and plane (100) and backscattered α-particles from InSb crystal, doped with Be ions. Although, Be ion dose in this case ex- ceeds by two order of magnitude the optimum dose, the radiation damages of a doped crystal are insignificant, as follows from these data. The γ-quantum yield from the reaction in a minimum of angular dependence is close to the yield of backscattered α-particles and the width at half-height of a hole of γ-quanta is the same as for α-particles. This means, that even in this case practi- cally all the introduced Be atoms even in this case prac- tically all the introduced Be atoms are electrically ac- tive. Promising is the use of accelerators and nuclear methods for studying the structure and properties of metal oxide compounds junctions and, first of all, high- temperature superconductors (HTSC). To optimize the technology of crystals La2-xSrxCuO4 and Nd2-xCexCuO4 a cycle of works was conducted. It is shown, that the oxy- gen sub lattice is disordered by 20 % relatively to sub lattices of Cu and La. A distinction in the amplitude of oscillation of atoms О1 and О2 was observed. It is es- tablished, that the rate of radiation destruction of the oxygen sub lattice is higher, than in cation sub lattices. The localization of implanted atoms of lithium and boron in La2-xSrxCuO4 is determined. Application of nuclear methods and accelerators for study of properties ferrite-metal oxide compounds (used in magneto-optics and calculation technique - ferrite- garnet films) and in quantum electronics (ticor), essen- tially, only begins. It is shown, that Tl4+ and Tl3+in the ticor lattice are disposed in tetrahedral interstitial site and interstitial site, respectively, displaced relatively to the aluminum sub lattice along direction <0001>. A po- sition of implanted atoms of B and N in the lattice of ferrite-garnet films is determined, a type of defects and relation between the profile of radiation defects and in- terstitial atoms are defined, and other problems are solved, too. 32 Table 1. Data of computer modeling obtained of isotopes on electrons accelerator Isotope Reaction Yield, Ci/mA(day) kw/mA 57Co 58Ni(γ,p)57Co, 58Ni(γ,n)57Ni→57Co 5.8*10-2 4.98 99Mo 100Mo(γ,n) 99Mo 5.05 5.18 181W 182W(γ,n)181W 1.24 7.60 185W 186W(γ,n)185W 0.56 7.60 For study of peculiarities of particle channeling the specialists of KIPT offered an approach, based on the use of nuclear reaction resonances. Nuclear reactions, besides other advantages, allow studying both domains adjacent to atomic chains or to planes, and a central do- main of the channel. Application of reactions with nar- row resonance allowed one to study a fine structure of anomalous high radiation yields in channeling. A new method for determination of bremstrahlung energy loss- es of hyperchanneled particles is suggested. In Fig. 11 shown is the angular dependence of the gamma-quanta of the reaction 13С(р,γ)14N from the Ni crystal, contain- ing the dissolved atoms of isotope 13С and protons scat- tered on nuclei of Ni atoms. From these data is follows, that the C atoms in Ni crystals are disposed in octahe- dral interstitial sites. 7. METHODS AND TECHNOLOGIES OF ISOTOPE PRODUCTION FOR MEDICINE AT AN ELECTRON ACCELERATOR A possibility in principle to generate isotopes for nu- clear medicine in photonuclear reactions under influ- ence of high-energy bremsstrahlung radiation produced by the electron accelerator is known for a long time. At the same time, their realizations become possible only with creation of powerful accelerators [9] and with de- velopment of required technologies [10]. Computer simulation. For analysis of efficiency of diverse isotope production, and also determining the ra- diation and thermal loading on the target one have de- veloped the methods of computer simulation of the pro- cesses of interaction of accelerated electrons and bremsstrahlung-produced photons with elements of the target device [11]. Hence, the data on isotope yields in dependence on the initial electron energy and bremsstrahlung converter composition were obtained. So, in Table 1 are given the results of calculation of a daily isotope production (25 МeV, 1 mA) with using the target of natural isotope composition 10 mm in thick- ness. Technology. 99Мо is a parent isotope 99mTc, providing a basic volume of analyses by the method gamma-scintigrapgy. To produce 99Mo at the electron accelerator one studied two types of targets: solid (composed of a set of plates from natural Mo cooled with water) and liquid (base on a Mo solution in water solution NaOH [11]). 57Co. As it is known, in Ukraine the own production of topographic gamma-chambers is arranged. For set- ting up and calibration of their measuring line an iso- tope source with radiation close to 99mTc, but with large half-life period is required. The most suitable was 57Co. The Conditions of chamber calibration determine the basic requirements to the source: activity of ≈µCi and no uniformity of distribution of an exposure dose power within the working area of the chamber (400 mm in di- ameter) no more than 1 % with meeting the require- ments of Ukraine’s radiation safety standards URSS -97 as for radiation levels outside the shielding unit of the source.) To this end we have conducted a pilot production of 57Co sources. So, at the accelerator LA-20 a target was established comprising a converter of bremsstrahlung radiation in the form of two elongated plates from Ta of 1.2 mm thickness each and plates from nickel of 1.5 mm thickness and dimension 28×84 mm2, placed immedi- ately behind the converter. The plate, in its turn, was composed of three easy separable parts of dimension 28 ×28 mm2. Irradiation was carried out during 100 hours at a mean value of a beam current 530 µA, pulse current 670 mA and mean value of electron energy E=28 МeV. After exposition during 20 days (for decay of short- lived “background” isotopes) we conducted the spectro- metric study of a prototype of the 57Со source (plates of 28х28 mm) obtained. Its activity was 2 mCi at a total activity of background radionuclides no more than 1%. 181W and 185W. Production of these isotopes is sup- posed to be made mainly in the solid target version with continuous cooling by circulating water. Metrological maintenance. One of basic conditions to ensure the effective and safe technology of isotope production is providing monitoring of accelerator radia- tion parameters and output isotope production. On the base of PC specialized system for control of bremsstrahlung radiation [12] and target activity and de- vice for analysis of its isotope composition were devel- oped. Considerable possibilities of a linear electron accelerator can be realized by making isotopes for braphytherapy. In this case the samples with a high specific activity are required. The original methods of creation of high-intense γ-radiation in small volumes, developed at R&D Complex “Accelerator", allow one to produce 103Pd with a specific activity of 1.5 mCi an samples of 6 mg weight. For this the reactions: 104Pd(γ ,n)103Pd, (T1/2=16.9 days, Q=−10,0 МеV) are used. The abundance of 104Pd is 11.4 %. The isotope 103Pd is promising for prostate cure. A Pd sample with a wall thickness of 40 µm, diameter of 0.8 mm and length of 4.5 mm has weight 5.45 mg. The use a bremsstrahlung radiation beam up to attenuation in e times (µ =0,0411 cm2/g for Pd)(one can irradiate 3300 such samples filled with pyrocarbon (4460 are empty). The use of a moving target will allow one to obtain the activity of one samples of 110-120 МBk for an irradiation time of 34 days). After radiation cooling during 26 days a final activity of 103Pd will be 1 mCi.. The activity of 101mRh in this case will be 0,1 % of the activity of 103Pd. 8. PRODUCTION OF SHORT-LIVED RADIONUCLIDES Most of radionuclides means for medical diagnostics (≈ 80 %) is pharmaceuticals based on 99mTc. However, a rather essential (and even determining in a number of cases) role in diagnostics of a various kind of diseases is assigned to pharmaceuticals tagged by radionuclides as 11C, 13N, 150, 18F. These positron-active radionuclides are widely used all over the world as sources of annihilation gamma-radiation with the energy of 511 keV in positron-emission tomographs (PET). In connection with growing interest to the PET-technique and efforts undertaken for creation of a tomograph in NSC KIPT, it is expedient to study capabilities of production of short- lived radionuclides on the available electron linacs of NSC KIPT. The investigation are undertaken with the purpose of obtaining the experimental data about the values of spe- cific activity of short-lived radionuclides on particular targets in the operating 25 MeV linear accelerator of electrons "EPOS" with the beam power 10-20 kW. Experiments were performed to determine the spe- cific activities (Bq/g⋅µA) of 11C, 13N, 150, 18F radionu- clides of medical purpose for PET (positron-emission topography) which are realized under conditions of the electron linear accelerator LU-20 "EPOS" with power ≅ 20 kW. For this the following substances were used as targets: water (in glass capsules of 2 cm2 for medical purpose), powders of boron acid H3BO3 and boron ni- tride BN, films of fluoroplastic C2F4, and polyethylene (C2H2)n,. The powders were packed in containers from aluminum of 0.1 mm thick and 20 mm diameter. The films of fluoroplastic and polyethylene were in the form of disks of 16 mm diameter and manufactured from the tape of 0.2 mm thick. The samples were weighted with the analytical balance to the nearest ± 5mg; the refer- ence density values for materials being irradiated have been used. The target-samples prepared were mounted in the assembly with dimensions 25×40 mm2, which was placed onto the electron beam directly behind the lead converter of 2 mm thick. Especially for these works on the accelerator the following radiation conditions were created: electron energy – 25 MeV; average cur- rent – 400 µA; area of beam under scanning - 80×300 mm2; irradiation time – 10 min. The specific activity was determined on the measur- ing spectrometric bench for the counting rate (pulse/sec) of irradiated samples having the known chemical com- position and weight and the known density of accelerat- ed electron current. Spectrometric bench is equipped with a Ge(Li)-de- tector, electronics in CAMAC standard and computer IBM PC Pentium-133. The measured activity values were corrected for the detector efficiency in the given measurement geometry and for the dead time. After pro- cessing of all experimentally obtained spectra the decay curve was plotted over the values of counting sum under the photoabsorption peak (with taking into account the background). By the use of the program REGRESS the experimental data were fitted by the curve of the form A1=A·exp(-λ t), where λ is the decay constant, t is the time from the irradiation stopping, A - measured activi- ty on moment t, A1.- is the activity in a moment of irra- diation stopping. Besides, the measurement errors were calculated with regard to the main factors. Specific ac- tivity is: 1 0 m S J k ΑΑ = η ⋅ ⋅ ⋅ ⋅ (Bq/g µA), where m and S are mass and area of the sam- ple, J is the mean current density' on the converter (µ A/cm2), η is the detector efficiency with taking into ac- count the solid angle, k is the multiplicity- coefficient of γ-quanta, A1 is the activity of the sample in a moment of irradiation stopping. Under irradiation condition note above the position-emitting radionuclides 11C, 13N, 150, 18F with specific activity (in Bq/g⋅µA) 1.9·107; 1.67·106; 2.5·106; I.7·IO6 respectively are obtained. A comparison between the experimental data on pro- duction of isotopes 11C, 13N, 150, 18F and calculation re- sults of other authors was done. This comparison shows that the experimental values of specific activities of 11C, 13N, 15O are in satisfactory agreement with calculation data of Mac Gregor and Lutz. However, the distinctions between calculated and measured activity- values can be explained by differ- ences in the irradiation geometry for different authors as well as by uncertainties in the bremsstrahlung spectrum. The observed exceeding (approximately by a factor of 5) of the experimental value of radionuclide 18F pro- duction as compared to the calculated one is related to the contribution of the process of production from neu- trons according to the reaction 19F(n,2n)18F that can take place under conditions of the "EPOS" accelerator. In Table 2 the comparative data on production 15O in various accelerators of electrons are given. One can see that the production of 15O on the accelerator "EPOS" in 200 cm3 of a water for 10 minutes of irradiation is 26 times more, than is required (5 mCi) for examination of one patient. The data are shown that 25 MeV electron linac with power of the beam about 20 kW able to meet competi- tion with cyclotron in short-lived isotopes for PET and 99mTc production. Additional advantages of the electron linac application for medical radionuclides production is its comparability with other traditional accelerators pro- grams such as sterilization, activation analysis, radiation modification of polymers and semiconductors etc. A rather low cost of the electron accelerator with the beam power ≈ 20 kW creates some additional perspectives. It allows one to use an "electron linac" not only as a tool for production of short-lived radionuclides for diagnos- tics in a combination with PET, but also for steriliza- tion, gamma-therapy, and for creation of a multi-pur- pose source of neutrons with a flow of ≈1013 n/s. thus expanding both scientific and applied capabilities of ra- diation technology. Authors greatly appreciate the participation of G.L. Bochek, V.I. Kulibaba, I.M. Prokhorets, D.G. Pu- gachev, A.A. Kapliy and V.D. Ovchinnik. Table 2 Source of information Linac "Fakel" Kurchatov IAE, Moscow Linac-30 MeV Center of Nuclear Medicine. USA. Cincinnati Linac "EPOS" NSC KIPT, Kharkov Conditions ofirradiation E0=30 MeV Iav=l00 µA Tirr=7 min V=200 cm3 E0=26 MeV Iav=l00 µA Tirr=4 min V=500 cm3 6×18 cm E0=25 MeV Iav=l00 µA Tirr=10 min V=200 cm3 Integral activity ina mo- ment of the end of irradia- tion 700 mCi 184 mCi 130 mCi (recalculation to 1 cm3) REFERENCES 1. N.P. Dikiy, E.P. Medvedeva, N.A. Shlaykhov et al. Physicals-analytic complex in medicine. Statistic processing. Computer diagnostics. Preprint KIPT 94-13, Kharkov, 1994, 17 p. (in Russian). 2. N.P. Dikiy, A.N. Dovbnja, A.A. Valter et al. Gam- ma-activation analysis of 187Os in MoS2 // Vopr. Atomn. nauki i tekhn., issue: nuclear-physics re- search. 1999, issue1 (33), p.64-65 (in Russian). 3. A.A. Valter, N.P. Dikiy, L.Z. Skakun et al. Distribu- tion of gold in Ukraine ores and its influence on se- lection of analysis methods for prospecting and in- dustrial exploitation of deposits // Mineralog. Zhourn. 1994, v. 16, №5/6, p.76-83 (in Russian). 4. N.P. Dikiy, A.A. Valter, A.N. Dovbnya et al. Gam- ma- activation analysis of noble metals in ores // Mineralog Zhourn. 1995, v. 17, №6, p. 85-89 (in Rus.). 5. N.P. Dikij, A.A. Valter, A.N. Dovbnya, E.P. Medvedeva, Ju.V. Lyashko, V.E. Storizhko, N.A. Shlyakhov. Accelerator based techniques for geology and medicine. 5 Russian-Ukrainian-German analytical symposium // Modern Aspects of Analyti- cal Chemistry. Aachen: Mainz. 1997, p.189-192. 6. W. Seiler. The cycle of atmospheric CO // Tellus, 1974, v. 26, №116, p. 118-135. 7. N.P. Dikiy, E.P. Medvedeva, O.I. Beskorovainaya et al. Method of X-ray radiation in determination of the microelement status in breathing organs diseases in children // Abstracts of 47 int. conf. on nuclear spec- troscopy and structure of atomic nucleus. S.-Peter- burg: 1997, p.319 (in Russian). 8. A.N. Dovbnya et al. Electron Linacs Based Radia- tion Facilities of Ukrainian National Science Center “KIPT" // Bull. of Amer. Phys. Soc. 1997, v. 42, № 3, p. 1391. 9. V.L. Uvarov, N.P. Dikiy, A.N. Dovbnya et al. Elec- tron Accelerator Based Production of Technetium- 99 m for Nuclear Medicine // Ibid B2LET of APC. 1997, v. 42, №3, p. 123 (in Russian). 10.N.P. Dikiy, A.N. Dovbnya, S.V. Maryokhin, V.L. Uvarov. On Efficiency of Medical & Biophysi- cal Isotopes Production Using an Electron Accelera- tor // Vopr. Atomn. nauki i tekn. Series:“Nuclear- physics research" (34). 1999, № 3, p. 91-92 (in Rus- sian). 11.V.L. Uvarov, S.P. Karasyov, S.V. Maryokhin et al. A Beam Monitoring & Calibration System for High- Power Electron Linacs // Bull. of Amer. Phys. Soc. 1997, v. 42, № 3, p. 1367. National Science Center “Kharkov Institute of Physics and Technology”, Kharkov, Ukraine Isotope 57Co REFERENCES
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institution Digital Library of Periodicals of National Academy of Sciences of Ukraine
issn 1562-6016
language English
last_indexed 2025-12-07T18:57:04Z
publishDate 2001
publisher Національний науковий центр «Харківський фізико-технічний інститут» НАН України
record_format dspace
spelling Dikiy, N.P.
Dovbnya, A.N.
Uvarov, V.L.
Khazhmuradov, М.A.
Shramenko, B.I.
2015-03-17T11:13:06Z
2015-03-17T11:13:06Z
2001
Use of accelerators in geology, medicine, isotopes production and atomic power energetics / N.P. Dikiy, А.N. Dovbnya, V.L. Uvarov, М.А. Khazhmuradov, B.I. Shramenko // Вопросы атомной науки и техники. — 2001. — № 1. — С. 26-35. — Бібліогр.: 11 назв. — англ.
1562-6016
PACS: 28.41.Kw.
https://nasplib.isofts.kiev.ua/handle/123456789/78439
Some examples of using of nuclear-physical methods in contiguous domains are presented.
Authors greatly appreciate the participation of G.L. Bochek, V.I. Kulibaba, I.M. Prokhorets, D.G. Pugachev, A.A. Kapliy and V.D. Ovchinnik.
en
Національний науковий центр «Харківський фізико-технічний інститут» НАН України
Вопросы атомной науки и техники
IHEPNF NSC KIPT in the last decade
Use of accelerators in geology, medicine, isotopes production and atomic power energetics
Использование ускорителей в геологии, медицине, производстве изотопов и атомной энергетике
Article
published earlier
spellingShingle Use of accelerators in geology, medicine, isotopes production and atomic power energetics
Dikiy, N.P.
Dovbnya, A.N.
Uvarov, V.L.
Khazhmuradov, М.A.
Shramenko, B.I.
IHEPNF NSC KIPT in the last decade
title Use of accelerators in geology, medicine, isotopes production and atomic power energetics
title_alt Использование ускорителей в геологии, медицине, производстве изотопов и атомной энергетике
title_full Use of accelerators in geology, medicine, isotopes production and atomic power energetics
title_fullStr Use of accelerators in geology, medicine, isotopes production and atomic power energetics
title_full_unstemmed Use of accelerators in geology, medicine, isotopes production and atomic power energetics
title_short Use of accelerators in geology, medicine, isotopes production and atomic power energetics
title_sort use of accelerators in geology, medicine, isotopes production and atomic power energetics
topic IHEPNF NSC KIPT in the last decade
topic_facet IHEPNF NSC KIPT in the last decade
url https://nasplib.isofts.kiev.ua/handle/123456789/78439
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