Nuclear technologies for producing radioactive isotopes are considered with a focus on the radionuclides used as radiopharmaceuticals in state-of-art methods of cancer diagnosis and radionuclide therapy—theranostics. New target materials and nuclear reactions for producing these radionuclides are considered. Results are presented from experimental and theoretical studies of the excitation functions of (p, xn) reactions in the 6–80 MeV range of energies for medium mass nuclear systems to produce such radionuclides as scandium, technetium, antimony, and terbium. These radionuclides are promising for their use in the diagnostics, therapy, and theranostics of nuclear medicine.

A simple sublimation technology for the lutetium and ytterbium separation was proposed, which already at the stage of preliminary experiments showed effectiveness: (a) the completeness of Yb separation resulted in short-term thermal annealing is at least 98%, the distilled product is completely free from 177 Lu, no additional preparation of ytterbium for repeated irradiation is required ; (b) traditional ion-exchange chromatography can be used for the final purification of 177 Lu from ytterbium.

We present a description of the originally developed ������-spectrometer consisting of two Si(Li)-detectors with sensitive area thickness above 8 mm and 4 ������-geometry. The full absorption spectrometer allows for direct measurements of ������-spectra, disregarding the corrections to response function induced by the electron backscattering from the crystal surface. In case of ������-spectra of transitions to the excited state of the daughter isotope additional 3 & DPRIME;BGO-detector is used in order to detect the ������-quanta in coincidence with the pair of Si(Li)-spectrometers.

An internal target placed in the chamber of a synchrotron is used as a neutron source for a spallation experiment. Moderators are used to create regions with different temperatures of neutrons. Neutron fluxes are measured using monitors (thin foils) and an HPGe detector. Monte Carlo calculations of neutron transport are used in planning the experiment.

238 Pu/ 239 Pu nitric acid solutions of unknown composition and concentrations of radionuclides are studied at a laboratory for the reprocessing of spent nuclear fuel. Studies show the solutions contain 240 Pu and 241 Am radionuclides in addition to the radionuclides mentioned above, and the concentrations of these isotopes are determined.

The study of the processes and mechanisms of the medium group mass nuclear systems formation (formed in reactions with protons) has both an important fundamental and practical significance. These tasks are especially important for the production of medical radionuclides, which are used for the effective early diagnosis and treatment of the various cancers. Combining the methods of radionuclide imaging with the methods of radionuclide therapy (therapy plus diagnostics—theranostics), it is possible to implement unique methods of non-surgical treatment of tumors with their precise visualization and minimal side effects. Therefore, in this work the experimental and theoretical studies of the nuclear reaction excitation functions with targets: 117Sn and 119Sn in the proton energy range of 6–18 MeV are carried out. Cross sections of the formation of antimony radionuclides are obtained for these reactions, and the mechanisms of such reactions are analyzed. Antimony radionuclides are promising for use in theranostics.

Precision β-spectra measurement always had a great importance in some fundamental physics problems including neutrino physics. Magnetic and electrostatic spectrometers have high resolution, but at the same time usage of such kinds of equipment involves the size and cost issues. Since electron mean free path at the energy of 3 MeV (which is basically the maximum energy of a β-transition for the long-lived nuclei) does not exceed 2 g/crn 2 , electron registration could be effectively performed with the solid state scintillators and semiconductors. A strong probability of backscattering from detector surface is present in case of semiconductor detectors and is dependent upon the detector material. Such problem can be solved with 4π geometry detector development, which fully covers the radioactive source and is able to register the backscattered electrons. In this work we present the newly developed technology of 4π geometry β-spectrometer based on two semiconductor detectors. This spectrometer was used for measurement of the 144 Ce - 144 Pr spectrum, that is the perspective anti-neutrino source due to endpoint energy at 3 MeV and can be used for the sterile neutrino search experiments. The form-factor parameters that were obtained are: C(W ) = 1 + (-0.02877 ± 0.00028)W + (-0.11722 ± 0.00297)W -1 . The measurement accuracy was sufficiently enhanced with respect to the previous results.

The shape of 210 Bi β-spectrum was measured using a spectrometer based on Si(Li) detectors with a 4π geometry. Full absorption spectrometer allows for a direct measurement of the β-spectra without using the electron backscattering corrections for the response function. The measured value of nuclear shape factor C(W)=1+(-0.4378±0.0072)W+ (0.0526±0.0021) W 2 is in agreement with the results of previous studies.

A 4π β spectrometer consists of two Si(Li) detectors with a sensitive region that is more than 8-mm thick. Using this total-absorption spectrometer it is possible to make a direct measurement of β spectra without correcting the response function for the electron backscattering from the crystal surface. The β spectra of transitions to the excited states of daughter nuclei have been measured using an additional 3'' BGO detector of γ rays, which is connected in coincidence with the pair of Si(Li) detectors.

The paper deals with measurements of carbon-14 in irradiated nuclear graphite. It suggests approaches to the problem, impart experience in production and calibration of new C-14, reference standards got from irradiated elements (sleeve, block) of the uranium–graphite reactor (UGR) stacks. Reference standards in the form of irradiated graphite were created and certified by the C-14 concentration. The concentration of C-14 in different samples was determined by interlaboratory comparisons. Results of the work proved an opportunity of creating reference materials for the C-14 radionuclide based on irradiated graphite obtained from the graphite elements of the uranium–graphite reactors. C-14 reference standards with different concentrations of interfering Cl-36, Co-60, H-3, Cs-137, Sr-90 and other radionuclides can be used for future development of new methods of determination the C-14 concentration in irradiated graphite and spectrometric equipment calibration.

The precision measurement of beta-spectrum shape for Bi-210 (historically RaE) has been performed with a spectrometer based on semiconductor Si(Li) detector. This first forbidden nonunique transition has the transition form factor strongly deviated from unity, and knowledge of its spectrum would play an important role in low-background physics in the presence of Pb-210 background. The measured transition formfactor could be approximated as C(W ) = 1 + (-0.4470 +/- 0.0013)W + (0.0552 +/- 0.0004)W-2, that is in good agreement with previous studies and has significantly increased parameter precision.

By applying the standard technique of co-precipitation of ferric- and ferrous salts with ammonium hydroxide in an inert atmosphere, the magnetite nano-crystallites have been prepared labelled with Auger- and internal conversion electrons, beta- and alpha-emitters (Co-57, Co-60 and Am-241 radionuclides). It has been confirmed by the methods of both X-ray phase analysis and Absorption Mossbauer Spectroscopy that for both cases (the "pure" crystallite and the ones doped with radionuclides), it is nanoparticles of a spherical shape that were synthesized with a magnetite structure and crystallites with a diameter of 12-18 nm; there were no admixtures of other iron compounds detected. It has been shown that the governing stabilization factor for the daughter iron atoms that were produced in 57Co(II) as a result of electron capture (EC) is the size of the atom whose position is originally occupied by the parent atom: in the emission spectra there are only Fe2+-species "present". A comparative analysis has been conducted of radiation-induced damage patterns in nano-crystallites in the dependence of nuclear- and physical characteristics of the radioactive tracer and total fluence. It has been established that under irradiation there is a comminution of crystallites taking place, the effective magnetic fields on the iron atoms in the labelled nano-crystallites remaining unchanged irrespective of the "dose load". Resulting from the decay of Am-241, the daughter nucleus receives the energy of 92.3 keV, the range of Np-237 nuclei (while the account is taken of the entire cascade of possible collisions) amounting to almost 40 nm, which is twice the size of "nano-containers" (the escape of Np-237 from the volume of crystallites is experimentally confirmed by the method of 2 pi alpha-counting).

The electron capture consequences in the Co-57 DOTA complex compound and processes of radiation-induced defect formation in DOTA under the effect of recoil nuclei produced after the alpha-decay of Am-241 were studied using high performance liquid radiochromatography and emission Mossbauer spectroscopy. The experiments conducted have shown that the production of targeted RPHs on the base of alpha-emitters and when applying the conventional approach (biologically active molecular construct with any chelate carrying a radioactive tracer) is just a scientific mystification, since the recoiling alpha-emitting nucleus causes a destroying effect on the neighboring substrate molecules and entirely excludes the targeted transport of the preparation. This is a bold conclusion indeed. However, it is confirmed in part by the works of other authors and by the fact that the encapsulation of alpha-particle emitters in inorganic (rather than organic) nanocontainers significantly decreases the negative effect of recoil nuclei on the carrier molecule and allows radiation treatment to be done of cancerous tissues, which is similar to hadron therapy. It is the recoiling nuclei (and not at all the emitted alpha-particles) that possess a huge destroying ability and exert a therapeutic effect when conventional approach (biologically active molecular construct with any chelate carrying a alpha-emitters) are used. The amount of radiation-induced damage in a matrix, caused by a recoil nucleus with a typical energy of approximately 100 keV is by a factor of several hundreds higher than the amount caused by the 5-7 MeV alpha-particles. If a labelled molecular construction has reached the tumor cell, there is no doubt in the "prioritative" action of recoil nuclei as compared to that of alpha-particles. However, the picture changes dramatically if the recoil impact "is blocked" at the location where an alpha-particle is emitted (e.g., in inorganic nanocontainers). A success in the development and production of pharmaceutical forms based on alpha-emitters is possible only when the pernicious influence of recoil nuclei is "blocked" owing to a high radiation stability of labelled compounds or owing to other "means of transportation" of the radionuclides to lesions. A reasonable alternative to alpha-emitters might be Auger- and internal conversion electron emitters that possess (as it is shown by the present studies and, which is of more importance, by the worldwide radionuclide practice) by incomparably higher radiation stability of labelled compounds.

A relevant approach was found to study the glass-forming region, macroscopic properties and electrical conductivity changes in the Tl2S-GeS-GeS2 system by analysing two composition glass lines (Tl2S)(x)(GeS2)(100-x) (0 <= x <= 50) and (Tl2S)(10)(GeS)(x)(GeS2)(90-x) (0 <= x <= 90) together with three thallium containing crystalline compounds Tl4Ge4S10, Tl4Ge2S6 and Tl4GeS4 . The crystallisation ability variation in the binary Tl2S-GeS2 system can be explained comparing the structural characteristics of glasses and closest crystalline compounds. The room temperature dc conductivity increases by 7 orders of magnitude with increasing thallium concentration and reaches the value of 10(-)(8) S cm(-1) for (Tl2S)(50)(GeS2)(50) sample. Combined with the previously obtained conductivity and thallium diffusion parameters for (Tl2S)x(GeS)60(GeS2)40-x and (Tl2S) x (GeS)50-x/2(GeS2)50-x/2 composition lines as well as with conductivity characteristics for the crystalline analogues, the ionic and electronic conductivities in the (TI2S)x(GeS2)loo-x glasses were estimated separately. The TI-poor glasses (x <= 0.25) are essentially semiconductors, while the TI-rich vitreous alloys appear to be ionic conductors. The conductivity parameters for (Tl2S)(10)(GeS)(x)(GeS2)(90-x)( )glasses change non-monotonically with GeS concentration passing by the conductivity minimum for 60% mol. GeS. The same behaviour was observed for thallium free (GeS)(x)(GeS2)(100-x) matrix, showing the influence of the GeS/GeS2 ratio on the properties of the thalliumpoor semiconducting glasses. (C) 2018 Elsevier B.V. All rights reserved.

Mixed-ligand metal-polymer complexes (MPC) of N-vinylpyrrolidone-N-vinylformamide-N-vinyl iminodiacedic acid (VP-VFA-VIDA) copolymers and diethyldithiocarbamate (DEDTC) as a co-ligand with indium were synthesized under mild conditions and pH close to physiological values. Isolated MPC were characterized by UV, IR, H-1 NMR, atomic absorption spectrophotometry, and HPLC. The obtained data implied that the MPC contain 8-10wt% of (IDA)In(DEDTC) fragments. The optimal conditions for radiochemical synthesis of VP-VFA-VIDA-In-111-(DEDTC) metal-polymer complex with mixed ligands were defined. The closest coordination environment of In-111 was studied by perturbed angular correlation technique. The obtained data are in good agreement with the information about weight amounts of the corresponding indium MPC.

Conductivity isotherms of (CdTe) x(AgI)0.5- x/2(As2Te3)0.5- x/2 glasses (0.0 ≤ x ≤ 0.15) reveal a nonmonotonic behavior with increasing CdTe content reminiscent of mixed cation effect in oxide and chalcogenide glasses. Nevertheless, the apparent similarity appears to be partly incorrect. Using 110mAg tracer diffusion measurements, we show that semiconducting CdTe additions produce a dual effect: (i) decreasing the Ag+ ion transport by a factor of ≈200 with a simultaneous increase of the diffusion activation energy and (ii) increasing the electronic conductivity by 1.5 orders of magnitude. Consequently, the conductivity minimum at x = 0.05 reflects an ionic-to-electronic transport crossover; the silver-ion transport number decreases by 3 orders of magnitude with increasing x.

The procedure of the directed synthesis of N-vinylpyrrolidone-N-vinylformamide (VP-VFA) copolymers with grafted iminodiacetate (IDA) chelating units is presented. The methods for labelling resulting conjugates with indium-113m were developed. The metal-copolymer conjugates were characterized by different physicochemical methods, including IR and NMR, viscometry, light scattering, and exclusion high-performance liquid chromatography. Parameters of radiochemical synthesis of the conjugates labelled with indium-113m were optimized. It was shown that the VP-VFA-IDA copolymer firmly binds indium-113m both in the acid and alkaline solutions, with pH of the reaction mixture having almost no effect on the complexation. VP-VFA-IDA-In conjugates were found to be unstable in histidine challenge reaction.