G. Ya. Novikova
Russian Academy of Sciences
Network
Latest external collaboration on country level. Dive into details by clicking on the dots.
Publication
Featured researches published by G. Ya. Novikova.
Radiochemistry | 2007
N. A. Danilov; E. A. Yanovich; N. P. Nesterova; G. V. Kostikova; A. Yu. Tsivadze; Leonid B. Bezrukov; I. R. Barabanov; C. Cattadori; G. Ya. Novikova; Yu. S. Krylov; A. Di Vacri
A comparison was made of the properties of solvents meeting the requirements posed on Gd-loaded organic liquid scintillators (transparency, light output, compatibility with the structural materials of the detector). The optical properties of the solvents were examined in relation to various factors (purity of the initial reagents, concentrations of Gd and scintillation additives). Extraction of Gd with C4 C8 carboxylic acids was examined. The composition of the extractable Gd complexes with 2-methylvaleric and 2-ethylhexanoic acids, GdR3·3HR·mH2O (where m = 1–2, depending on the solvents used), was determined. The solubility of water in 2-ethylhexanoic and 2-methylvaleric acids was examined. Scintillators based on Gd 2-methylvalerates have better parameters than those based on the other carboxylic acids tested. The instability of the optical properties of the Gd carboxylate solutions is presumably due to the presence of water in the scintillator. Possible methods of water removal from the organic phase were discussed.
Russian Journal of Applied Chemistry | 2011
I. R. Barabanov; Leonid B. Bezrukov; N. A. Danilov; S. V. Kutsev; V. P. Morgalyuk; G. Ya. Novikova; V. V. Sinev; E. A. Yanovich
Properties of domestic linear alkylbenzene were subjected to a physicochemical study in order to enable use of this compound as the main solvent in large-volume liquid organic scintillators intended for neutrino experiments. New compositions of Gd-containing liquid scintillators based on linear alkylbenzene were suggested and examined.
Radiochemistry | 2011
N. A. Danilov; Yu. S. Krylov; V. I. Zhilov; A. Yu. Tsivadze; E. V. Sal’nikova; I. R. Barabanov; Leonid B. Bezrukov; G. Ya. Novikova; E. Ya. Yanovich; C. Cattadori; S. Nisi; M. Di Vacri; C. Salvo; A. Ianni
The Th content in commercially available Nd2O3 samples with the main substance content of 99.0–99.998% was found to be 2–8, and that of U, 3–230 ppb. Therefore, to obtain Nd meeting the requirements of the experiment on studying neutrinoless double β-decay, it should be purified to reduce the content of Th and U impurities by a factor of 103–104. To this end, the extraction of Nd, Th, and U from hydrochloric acid media with solutions of trioctylphosphine oxide (TOPO) in toluene was studied. The distribution ratios of Th increase with a decrease in the HCl concentration in the initial aqueous solution. With an increase in the Cl− concentration in the aqueous phase, the U distribution ratios decrease, probably because of a decrease in the concentration of the free extractant due to the extraction of Nd and HCl. On the contrary, the distribution ratios of Th increase with an increase in the Cl− concentration in the aqueous phase, with the slope of the straight line in the coordinates logDTh-log[Cl−]aq close to 7, which may be due to coextraction of Th with Nd in the form of the complex ThNdCl7. The enthalpies of formation of the extractable complexes of Th and U were determined from the temperature dependence of the extraction of Nd, Th, and U chlorides with a 0.1 M solution of TOPO in toluene. The optimal extraction system was chosen for Nd purification to remove traces of Th and U: organic phase, 0.1 M solution of TOPO in toluene; aqueous phase, 2.4 M NdCl3 + 0.1 M HCl. From the initial aqueous solution contaning 574 ppt Th and 2837 ppt U, by single extraction with an equal volume of 0.1 M TOPO in toluene, an aqueous solution containing <10 ppt Th and 31 ppt U (detection limit 10 ppt) was obtained. By semicountercurrent extraction, from the initial aqueous NdCl3 solution containing 200 ppb Th, the raffinate containing <10 ppt Th was obtained in one extraction step. The results obtained confirm the possibility of exhaustive removal of Th and U impurities (to the level of ≤1 ppt) from Nd by extraction with TOPO solutions from chloride solutions.
Russian Journal of Inorganic Chemistry | 2016
G. Ya. Novikova; N. I. Bakulina; Anna V. Vologzhanina; B. V. Lokshin; V. P. Morgalyuk
Optimal conditions have been found for the synthesis of a gadolinium 3,5,5-trimethylhexanoate complex for creation of stable Gd-loaded scintillators. Procedures for the preparation of gadolinium concentrates containing 10–20 g/L Gd in a linear alkylbenzene have been developed, and their stability has been studied. The structure of gadolinium complexes deposited from the concentrates prepared by extraction has been determined.
Instruments and Experimental Techniques | 2012
I. R. Barabanov; Leonid B. Bezrukov; C. Cattadori; N. A. Danilov; A. Di Vacri; Aldo Ianni; S. Nisi; G. Ya. Novikova; F. Ortica; A. Romani; C. Salvo; O. Yu. Smirnov; E. A. Yanovich
A new Nd-loaded liquid organic scintillator based on pseudocumene (PC) solvent was developed for the experiment aimed at searching for 0νββ decay of a 150Nd nucleus. The optical characteristics of the scintillator were measured for several Nd concentrations. The measurements taken using two modules 1 and 2 m in length have made it possible to determine the effective attenuation length of the PC scintillator containing Nd (6.5 g/L). It was demonstrated that the scintillator characteristics remained unaltered over 1 year. The content of radioactive contaminants was analyzed, and the sensitivity of the experiment to effective Majorana neutrino mass 〈mν〉 ∼ 0.05–0.10 eV was estimated for a detector containing a 12-ton scintillator.
Russian Journal of Inorganic Chemistry | 2009
G. Ya. Novikova; I. R. Barabanov; Leonid B. Bezrukov; L. I. Belous; N. A. Danilov; A. A. Ivanov; R. H. Ziganshin; E. A. Yanovich
The formation of coordination compounds between gadolinium 2-methylvalerate (Gd(2MVA)3) and trioctylphosphine oxide (TOPO) in a gadolinium-loaded liquid scintillator (GdLS) solution was studied by MALDI-TOF MS. The most abundant gadolinium-containing compound in the GdLS solution in the presence of TOPO is the monomer complex Gd(2MVA)3 · (TOPO)2. In the absence of TOPO, the solution contains only Gdn(2MVA)3n (n = 2–5) association species. Therefore, TOPO prevents carboxylate polymerization in the solution and can be used as a stabilizer of the gadolinium compounds in GdLS. The existence of the Gd(2MVA)3 · TOPO complex is confirmed by IR spectroscopy. The possibility of coordination between Gd(2MVA)3 and 2,5-diphenyloxazole (PPO), the most common scintillation admixture, has been investigated. No complexes between Gd(2MVA)3 and PPO have been detected by MALDI-TOF MS in the scintillator solution. IR spectroscopic data also do not provide any unambiguous indication of coordination between Gd(2MVA)3 and PPO.
Physics of Atomic Nuclei | 2017
I. Barabanov; L. Bezrukov; A. V. Veresnikova; Yu. M. Gavrilyuk; A. M. Gangapshev; V. Yu. Grishina; V. Gurentsov; V. P. Zavarzina; V. V. Kazalov; S. D. Krokhaleva; V. V. Kuz’minov; A. S. Kurlovich; B. K. Lubsandorzhiev; Sultim Lubsandorzhiev; A. K. Mezhokh; V. P. Morgalyuk; P. Yu. Naumov; G. Ya. Novikova; V. B. Petkov; A. M. Pshukov; A. Yu. Sidorenkov; V. V. Sinev; Sh. I. Umerov; E. Yanovich; T. Enquist; P. Kuusiniemi; J. Joutsenvaara; A. Virkajarvi
At the Baksan Neutrino Observatory (Institute for Nuclear Research, Russian Academy of Sciences, Moscow) deployed in the Caucasus mountains, it is proposed to create, at a depth corresponding to 4760 mwe, a large-volume neutrino detector on the basis of a liquid scintillator with a target mass of 10 kt. The detector in question is intended for recording natural fluxes of neutrinos whose energy may be as low as 100MeV. Neutrino fluxes from various sources are considered in the present study, and the expected effect in the proposed detector is estimated. The detector hat is being developed at the Baksan Neutrino Observatorywill become part of the world network of neutrino detectors for studying natural neutrino fluxes.
Russian Journal of Inorganic Chemistry | 2014
G. Ya. Novikova; N. I. Bakulina; V. P. Morgalyuk
Coordinatively saturated gadolinium compounds based on gadolinium 3,5,5-trimethylhexanoate Gd(TMHA)3 with additives of trioctylphosphine oxide and free 3,5,5-trimethylhexanoic acid were synthesized and studied to design Gd-containing scintillators for antineutrino detection. The obtained complexes were used for preparing 0.1% solutions of Gd in linear alkylbenzene and optical properties of the solutions were measured.
Radiochemistry | 2009
N. A. Danilov; Yu. S. Krylov; A. Yu. Tsivadze; I. R. Barabanov; Leonid B. Bezrukov; G. Ya. Novikova; E. A. Yanovich; L. I. Demina; C. Cattadori; A. Di Vacri
Complexes of Gd with carboxylic acids C4–C9 were prepared, and their properties were studied: solubility in water and organic solvents in relation to temperature, melting points, and decomposition points. A procedure was developed for removing water from gadolinium 2-methylvalerate Gd(2MVA)3 to a final content not exceeding 0.01%. To increase the solubility of Gd(2MVA)3 in low-polarity organic solvents and to stabilize the resulting organic solutions, it was suggested to add extractants such as 2-methylvaleric acid (H2MVA) or neutral organophosphorus compounds: triisoamylphosphine oxide (TIAPO) or trioctylphosphine oxide (TOPO). Liquid Gd-loaded organic scintillators based on Gd(2MVA)3 solutions with additions of H2MVA, TIAPO, and TOPO in trimethylbenzene (TMB), phenylxylylethane (PXE), and their mixtures with dodecane were prepared. Long-term tests (up to 2 years) of the stability of the optical properties of the scintillators obtained proved their stability at temperatures of up to 30°C. At elevated temperatures (40°C and higher), the scintillators degrade. The previously made suggestion that water in the scintillator negatively affects its optical properties in prolonged storage was confirm
Instruments and Experimental Techniques | 2017
I. Barabanov; L. Bezrukov; G. Ya. Novikova; E. Yanovich
The light yield in samples of a Nd-loaded scintillator was measured. The scintillator composition differed in the solvent (pseudocumene (PC) and a mixture of PC with linear alkyl benzene), the scintillating dye type (РРО or ВРО), and the Nd concentration. The light yield in the PC (PPO, 1.5 g/L), which was approximately 11500 photons/MeV, was assumed to be the standard. The ionizing-radiation sources were 137Cs, 241Am, and 109Cd radionuclides. It was shown that the light yield in the scintillator with a Nd concentration as high 30 g/L (~3%) in PC made it possible to attain energy resolution at a level of 3% at an energy of 3 MeV (neutrinoless 2β decay of 150Nd).