In experiments on the electron linac LUE-40 of RDC “Accelerator” NSC KIPT, the flux-averaged cross-sections σ(Еγmax)exp of photonuclear reactions 100Mo(γ,n)99Mo, 27Al(γ,x) 24Na, 93Nb(γ,n)92mNb, 93Nb(γ,3n)90Nb, and 181Ta(γ,n)180gTa were measured using the γ-activation technique. The theoretical flux-average cross-sections σ(Еmax)th were computed using the partial cross-section σ(Е) values from the TALYS1.9-1.95 codes and bremsstrahlung γ-flux calculated using GEANT4.9.2. Two different experimental setups were used in the experiments: an aluminum electron absorber and a deflecting magnet to clean the bremsstrahlung γ-flux from electrons. A comparison of the flux-average cross-sections measured for two experimental setups was performed. The possibility of using the reactions 100Mo(γ,n)99Mo,27Al(γ,x)24Na, 93Nb(γ,n)92mNb, 93Nb(γ,3n)90Nb, and 181Ta(,n)180gTa as monitors of the bremsstrahlung γ-flux for the energy range 30…100 MeV was investigated.

The flux-averaged cross-sections for the reactions Cu-65(gamma, n)Cu-64 Cu-63(gamma, n)Cu-62 Cu-63(gamma ,2n)Cu-61 , and have been measured within the bremsstrahlung end-point energy Cu-63(gamma, 3n)Cu-60 E-ymax range of 35-94 MeV. The experiments were performed with the electron beam from the NSC KIPT linear accelerator LUE-40 with the use of the activation and off-line gamma-ray spectrometric techniques. Theoretical calculation of the flux-average cross-sections was conducted using the cross-section values from the TALYS1.95 (y, n) and (gamma,2n) reactions of Cu-63 and Cu-65. For the reaction Cu-63 (gamma,3n)Cu-60, the values of were measured for the first time.

The process of "Glucose 11C" pharmaceutical production by means of a photonuclear reaction 12C(γ, n) 11C is considered. The parameters of bremsstrahlung and electron beam scattered in the converter are investigated and optimized. It is proposed to use a constant-field magnet to remove electrons from the photon beam. A magnet de-sign is proposed that allows obtaining a field of 0.5 T in a gap of 25 mm. The production of the 11C isotope in the glucose target was estimated.

The creation of a PET center in the Kharkov region is proposed. This is facilitated by the transfer of the cyclotron by the Julich Research Center (Germany) to Kharkiv, which will ensure the development of the diagnostic radiopharmaceutical “Glucose,18F”. An additional expansion of the treatment base is possible by acquiring a microtron electron accelerator, which will make it possible to produce and use for treatment of cancer the “Ethanol,11C” radiopharmaceutical and the "Glucose,11C" diagnostic radiopharmaceutical developed at the NSC KIPT.

Radiation technologies based on the use of powerful electron beams and gamma radiation are closely related to the need for dosimetry of these beams. Dosimetry based on the use of the inelastic gamma-ray scattering reaction on a number of nuclei with the formation of isomers with different half-lives and energies of radiation quanta is very successful for these purposes. An example of this application in dosimetry is the 115In (γ,γ')115mIn reaction, which results in the formation of the 115mIn isomer, having a gamma line with an energy of 336.24 keV and a half-life of 4.5 hours. There was a successful application of this technique in dosimetry in solving certain practical problems (irradiation complexes based on 60Co source- cobalt “guns”). In this work, it is shown that the use of In detectors for dosimetry of gamma-radiation with a wide energy spectrum (bremsstrahlung) is associated with significant uncertainty in measuring the equivalent dose of the gamma spectrum with an upper limit of 10 MeV. This uncertainty is due to the relatively high threshold of the aforementioned reaction of 1.08 MeV. The quantitative contribution to the total radiation flux of the region of the gamma spectrum below the threshold (γ,γ') of the reaction on the In nucleus was determined and it was shown that, depending on the direction of radiation, there is an systematic error in measuring the equivalent dose, reaching 20-60%. Investigated and proposed for use alternative materials detectors, allowing reducing the systematic error in measuring the equivalent dose to 2-3%, which is quite acceptable for practical use.

Обобщены результаты наработки фотоядерным способом изотопов 11С и 18F в различных мишенях-матрицах. Исследования выполнены на линейных ускорителях электронов НИК "Ускоритель" ННЦ ХФТИ НАН Украины в диапазоне энергий 10 -40 МэВ для выяснения возможностей получения максимально достижимых уровней активности изотопов 11С, и 18F с целью планирования дальнейших разработок по созданию на основе этих изотопов радиофармпрепарата (РФП) для ядерной медицины. В рамках вышеизложенного подхода нами проведены измерения уровней активности изотопа 18F переходящего в окружающую водную среду при облучении мишеней–матриц из фторопласта (С2F4) потоком тормозного излучения. Выход изотопа 18F в водную среду в самых благоприятных условиях (по энергии и среднему току пучка) составил 3,6 % от величины активности матрицы 40 МБк/г, что является весьма низким показателем. Несмотря на обнадеживающее значение удельной активности изотопа 18F в мишенях–матрицах фторида лития (LiF) -77 МБк/г и плавиковой кислоты (НF) – близкой к 100 МБк/г вопрос извлечения изотопа 18F из матриц С2F4, LiF и НF для приготовления на его основе РФП остается открытым и ставит под сомнение целесообразность такой методологии наработки изотопа 18F для дальнейшего использования. Более результативной оказалась наработка изотопа 11С в облученной мишене-матрице стандартной лечебной формы «глюкозы моногидрат» (глюкоза). Показано, что в результате облучения глюкозы пучком гамма-квантов удается осуществить «мечение» глюкозы изотопом 11С, который образуется в результате фотоядерной реакции 12С(γ,n)11C на ядре 12С, входящем в состав молекулы глюкозы - С6Н12О6 · H2O. Облученный образец глюкозы, растворенный в заданном объеме растворителя (дистиллированной воды) будет готовым к использованию РФП «Глюкоза, 11C». Показано, что «фотоядерный метод» обеспечивает получение РФП «Глюкоза, 11C» с полной активностью, необходимой для проведения ПЭТ диагностики. РФП «Глюкоза, 11C» к моменту его использования обладает 100% радионуклидной чистотой. РФП «Глюкоза, 11C» таким способом получен впервые. Обсуждается выбор оптимальной конструкции водоохлаждаемого мишенного устройства, обеспечивающего щадящий (в смысле тепловых нагрузок) режим облучения капсулы, заполненной таблетками глюкозы. Используя программу “SolidWorks FlowSimulation 2011”, рассчитаны количественные характеристики скоростей потоков воды, обтекающих капсулу с глюкозой и конвертер.

The results of the photonuclear production of C-11 and F-18 isotopes in various target-matrices are summarized. The studies were performed using linear electron accelerators of the R&DE "Accelerator" NSC KIPT NAS of Ukraine in the energy range 10 -40 MeV to determine the possibilities of obtaining the maximum achievable activity levels of C-11 isotopes, and F-18 with a view to planning further developments on the creation of radiopharmaceutical for these nuclear isotopes. In the framework of the above approach, we measured the activity levels of the F-18 which is transferred to the surrounding aquatic environment during irradiation of targetsmatrices of fluoroplastic (C2F4) with bremsstrahlung flux. The release of the F-18 isotope into the aquatic environment under the most favorable conditions (in terms of energy and average beam current) was 3.6% of the target-matrices activity - 40 MBq/g, which is a very low figure. Despite the encouraging value of the specific activity of 18F isotope in lithium fluoride (LiF) -77 MBq/g target-matrices and hydrofluoric acid (HF) - close to 100 MBq/g, the process of extracting F-18 from C2F4, LiF and HF as basis of the radiopharmaceutical is not sufficiently effective and brings into question the feasibility of such a methodology for producing F-18 isotope for further use. More efficient was the production of the C-11 isotope in the irradiated target-matrix of the standard therapeutic form "glucose monohydrate" (glucose). It was shown that, as a result of irradiation of glucose with a gamma-quanta beam, it is possible to "label" glucose with the C-11 isotope, which is formed as a result of the photonuclear reaction C-12(gamma, n)C-11 at the C-12 nucleus, which is part of the glucose molecule C6H12O6 center dot H2O. Irradiated sample of glucose dissolved in a given volume of solvent (distilled water) will be ready for use radiopharmaceutical "Glucose, C-11". It has been shown that the "photonuclear method" provides for obtaining the "Glucose, C-11" radiopharmaceutical complex with total activity necessary for performing PET diagnostics. The radiopharmaceutical "Glucose, C-11" by the time of its use has 100% radionuclide purity. "Glucose, C-11" obtained in this way was produced for the first time. The choice of the optimal design of a water-cooled target station, providing a moderate (in terms of heat loads) mode of irradiation of a capsule filled with glucose tablets, is discussed. Using the program "SolidWorks FlowSimulation 2011", the quantitative characteristics of the flow rates of water flowing around the glucose capsule and the converter are calculated.

The importance widely used in the world of Radiopharmaceutical: 2-fluoro [F-18]-2-deoxy-D-glucose (fluorideglucose, F-18) for the diagnosis of various diseases using PET and CT imaging are shown. Provides information about the levels of specific activity of aqueous solutions containing the isotope F-18, the resulting target irradiation-matrix of Teflon (C2F4) on different linear accelerators of electrons NIK "Accelerator". Emphasis on the need to increase the density of the electron flux on the target and find ways of improvement of the methodology for obtaining Radiopharmaceutical, using isotope F-18, produced by the photonuclear method.

The yields of A( $$\upgamma $$ ,X) $$^{7}$$ Be reactions induced by bremsstrahlung photons were measured at the endpoint electron energies of 40, 50, 60, 70, 80, and 90 MeV. Computer simulation of bremsstrahlung converter parameters was carried out with using the Geant4 toolkit. The cross sections for the A( $$\upgamma $$ ,X) $$^{7}$$ Be reactions on $$^{12}$$ C and $$^{14}$$ N nuclei were evaluated on the basis of the measured reaction yields and the calculated bremsstrahlung spectra. The agreement of the experimental and evaluated results was demonstrated for $$^{12}$$ C nuclei and partly for $$^{14}$$ N nuclei.

The yields of A(gamma, X)Be-7 reactions induced by bremsstrahlung photons were measured at the endpoint electron energies of 40, 50, 60, 70, 80, and 90MeV. Computer simulation of bremsstrahlung converter parameters was carried out with using the Geant4 toolkit. The cross sections for the A(gamma, X) 7Be reactions on C-12 and N-14 nuclei were evaluated on the basis of the measured reaction yields and the calculated bremsstrahlung spectra. The agreement of the experimental and evaluated results was demonstrated for C-12 nuclei and partly for N-14 nuclei.

Radiopharmaceuticals based on the Cu-67 isotope have found wide use in immunotherapy. The present paper analyzes the conditions of Cu-67 production by the Zn-68(gamma,p) Cu-67 reaction at an electron accelerator in relation to the target isotope and hot impurities yield, as well as the radiation risks. Consideration has been given to some variants of the technological target 40 g in weight made from natural zinc, and one enriched up to 99% in the Zn-68 isotope. The target exposition to bremsstrahlung with end-point energy 30 and 60 MeV was studied. It has been found that the use of enriched target results in reduction of both the radiation risk (down to 10(-4)) and the scope of waste handling procedures.

Possibility of a dosimetry method for high-energy bremsstrahlung radiation in the range up to MGy and higher by activation of a detector from indium via the In-115 (gamma,gamma') In-115m reaction with determination of absorbed dose on specific activity of the In-115m isomer is investigated. To study such an approach, a method based on joint irradiation of a stack of thin targets is offered. Each target includes the foils from indium and molybdenum of natural isotopic composition, and also a standard dosimeter in the form of a plate from PMMA. Preliminary study of indium activation (with due regard to known data on the reaction cross section), detector thermal stability, yield of the reference reactions Mo-92(gamma,2n)Mo-90 and Mo-100(gamma,n)Mo-99 as well as absorbed dose in PMMA, was conducted by means of computer simulation. The measurement of specific activity of In-115m, Mo-90 and Mo-99 was carried out jointly with the absorbed dose of in PMMA using the Harwell Red 4034 dosimeters. Sensitivity of the method against end-point energy of X-Ray in the range 8 to 71 MeV has been established.

The paper describes the results of the work on improvement of electron linac LUE-40. This linac has been designed for nuclear physics research in the electron energy range 40...100 MeV. The main purpose is to reduce the energy spread, emittance and long-term instability of the beam characteristics. For this purpose the system of klystron high voltage stabilization and the beam loading compensation system have been developed. The improved injector has been put into operation. A new DC power supply system of the magnetic spectrometer has been installed and tested.

This communication deals with the conditions of 192Ir isotope production under a nonreactor technology via the 193Ir(γ, n)192Ir reaction. It can be carried out by irradiation of a target from natural iridium with the high-energy X-ray of an electron accelerator. The possibility of increasing the photonuclear yield of the target isotope by addition of the 191Ir(n, γ)192Ir reaction induced by moderated photoneutrons has been shown. For this, an X-ray converter and a target were placed inside a neutron moderator. Data on the 192Ir and admixture yields for the techniques using the moderator and without it have been obtained by computer simulation and experimentally.

The yields of A ( Γ,X ) 7 Be reactions induced by bremsstrahlung photons were measured at the endpoint electron energies of 40, 50, 60, 70, 80, and 90MeV. The spectra of bremsstrahlung incident to the targets used were calculated via a simulation based on the GEANT 4 code passage. The cross sections for the A ( γ,X ) 7 Be reactions on 12 C, 14 N, and 16 O nuclei were evaluated on the basis of the measured reaction yields and the calculated bremsstrahlung spectra. The experimental cross sections for the photonuclear reactions of 7 Be production were comparedwith their counterparts calculated on the basis of the TALYS 1.4 package. Agreement of the experimental and evaluated results was demonstrated for 12 C nuclei and partly for 14 N nuclei.

The Be-7 isotope produced in the upper atmosphere under the action of cosmic radiation is an important factor in population radiation load. A correct determination of the radiation dose coming from this isotope calls for consideration of the photonuclear mechanism of Be-7 production by the nuclei of oxygen and nitrogen. The paper gives the experimental yields from A(gamma, X)Be-7 nuclear reactions in the bremsstrahlung beam versus the end-point energies of electrons (from 40 to 90 MeV). The mathematical model approach with the GEANT4 class library was used to calculate the spectra of bremsstrahlung incident on the targets. Based on the experimental results, we have calculated the A(gamma, X)Be-7 reaction cross-sections for oxygen, nitrogen and carbon. Calculated values of photonuclear reaction cross-sections for Be-7 production by C-12, N-14, O-16 nuclei were obtained with the use of the TALYS package. Agreement between experimental and calculated results only for C-12 and N-14 is shown.

Radioactive isotopes of palladium (Pd-103) and rhenimn (Ra-186 and Re-188) have found wide use in nuclear medicine. The present report deals with the conditions for their production by a photonuclear method at an electron accelerator. Studies have been made into the channels of target isotope/attendant impurity production as palladium and rhenium targets of natural isotopic composition were exposed to a mixed flux of X-ray (bremsstrahlung) with end-point energy of 40 MeV and photoneutrons. By placing a bremsstrahlung converter and the target inside a neutron moderator, data have been obtained for the effect of photoneutron spectrum on the isotope yield. The simulation technique has been used to investigate the photonuclear yield of target isotopes and major impurities as function of electron energy.

The deposition flux of cosmogenic 7Be in the industrial city Rostov-on-Don (Russia) from 2001 to 2011 has been measured. The variations of annual 7Be deposition flux appear to be mainly correlated with the number of the meteorological parameters and solar activity. For the first time correlations of the volume activity of cosmogenic 7Be with such meteorological parameters as temperature, precipitation, wind speed, atmospheric pressure, relative humidity are identified.