Publications (114)92.15 Total impact
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Article: Astrophysical and cosmological problems of invisible mass and dark energy in the Universe
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ABSTRACT: The Workshop on results of the Project Kosmomikrofizyka-2 (Astroparticle Physics) of the National Academy of Sciences (NAS) of Ukraine "Astrophysical and cosmological problems of invisible mass and dark energy in the Universe" was held on November 21-22, 2012 in the Institute for Nuclear Research, Kyiv, Ukraine (http://lpd.kinr.kiev.ua/kmf12). This Project was carried out during three years (2010-2012) by scientists from various universities and institutes of the National Academy of Sciences of Ukraine; it was a logical continuation of the previous scientific program of the NAS of Ukraine "Researches of structure and composition of the Universe, hidden mass and dark energy (Kosmomikrofizyka)" in 2007-2009. These programs were devoted to theoretical and experimental investigations in astronomy, astrophysics, cosmology, physics of atomic nuclei and particle physics, which are related with the problems of dark matter and dark energy in the Universe.04/2013; -
Article: Radioactive contamination of 7LiI(Eu) crystal scintillators
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ABSTRACT: The radioactive contamination of two 26 g samples of low background lithium iodide crystal scintillators doped by europium and enriched in 7Li to 99.9% (7LiI(Eu)) has been investigated by scintillation method at the sea level, and by ultra-low background HPGe γ spectrometry deep underground. No radioactive contamination was detected. In particular, the contamination of the crystal scintillators by 226Ra and 228Th does not exceed 1 mBq/kg, and the activity of 40K is less than 0.5 Bq/kg.Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment 03/2013; 704:40–43. · 1.21 Impact Factor -
Article: CdWO4 crystal scintillators from enriched isotopes for double beta decayexperiments
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ABSTRACT: Cadmium tungstate crystal scintillators enriched in 106Cd and 116Cd were developed. The produced scintillators exhibit good optical and scintillation properties, and a low level of radioactive contamination. Experiments to search for double beta decay of 106Cd and 116Cd are in progress at the Gran Sasso National Laboratories of the INFN (Italy). Prospects to further improve the radiopurity of the detectors by recrystallization are discussed.Radiation Measurements 03/2013; · 1.18 Impact Factor -
Conference Proceeding: First results of the experiment to search for double beta decay of 116Cd with the help of enriched 116CdWO4 crystal.
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ABSTRACT: A low background experiment to search for the double beta decay of 116Cd is in progress at the Gran Sasso National Laboratories of the INFN (Italy) by using 116CdWO4 crystal scintillators (~1.2 kg) enriched in 116Cd to 82%. The energy resolution of the detector is FWHM ~ 5.5% at Q_2beta of 116Cd (2813 keV), the background rate is 0.28 counts/(yr*keV*kg) in the 2.7–2.9 MeV energy range. After ~1 kg*yr of data taking, half-life of 116Cd relatively the 2nu2beta decay was measured as T1/2 = (2.5 ± 0.5)*1e19 yr and the new improved limits on the 2beta decay of 116Cd to few excited levels of 116Sn were set at level of 1e20-1e21 yr. In particular, 2nu2beta transitions to 2+ states (2112 and 2225 keV) of 116Sn were restricted on the level of 1e20 yr, approximately one order of magnitude higher than those established previously.4th Int. Conf. “Current Problems in Nuclear Physics and Atomic Energy" (NPAE-Kyiv2012), September 03–07, 2012, Kyiv, Ukraine; 03/2013 -
Article: Search for 2\beta\ decays of 96Ru and 104Ru by ultra-low background HPGe gamma spectrometry at LNGS: final results
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ABSTRACT: An experiment to search for double beta decay processes in 96Ru and 104Ru, which are accompanied by gamma rays, has been realized in the underground Gran Sasso National Laboratories of the I.N.F.N. (Italy). Ruthenium samples with masses of about (0.5-0.7) kg were measured with the help of ultra-low background high purity Ge gamma ray spectrometry. After 2162 h of data taking the samples were deeply purified to reduce the internal contamination of 40K. The last part of the data has been accumulated over 5479 h. New improved half life limits on 2\beta+/\epsilon \beta+/2\epsilon\ processes in 96Ru have been established on the level of 10^{20} yr, in particular for decays to the ground state of 96Mo: T1/2(2\nu 2\beta+) > 1.4 10^{20} yr, T1/2(2\nu \epsilon\beta+) > 8.0 10^{19} yr and T1/2(0\nu 2K) > 1.0 10^{21} yr (all limits are at 90% C.L.). The resonant neutrinoless double electron captures to the 2700.2 keV and 2712.7 keV excited states of 96Mo are restricted as: T1/2(0\nu KL) > 2.0 10^{20} yr and T1/2(0\nu 2L) > 3.6 10^{20} yr, respectively. Various two neutrino and neutrinoless 2\beta\ half lives of 96Ru have been estimated in the framework of the QRPA approach. In addition, the T1/2 limit for 0\nu 2\beta- transitions of 104Ru to the first excited state of 104Pd has been set as > 6.5 10^{20} yr.Physical Review C 02/2013; 87(3):034607. · 3.31 Impact Factor -
Article: On the potentiality of the ZnWO4 anisotropic detectors to measure the directionality of Dark Matter
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ABSTRACT: In the anisotropic scintillators the light output and the pulse shape for heavy particles (p, α, nuclear recoils) depend on the direction with respect to the crystal axes; the response to γ/β radiation is isotropic instead. This feature offers the possibility to study the directionality approach, which is applicable in the particular case of those Dark Matter candidate particles inducing just nuclear recoils. Among the anisotropic scintillators, the ZnWO4 has unique features, which make it an excellent candidate for this type of research, and there is still plenty of room for the improvement of its performances. In this paper the possibility of a low background pioneer experiment (named ADAMO—Anisotropic detectors for DArk Matter Observation) to exploit deep underground the directionality approach by using anisotropic ZnWO4 scintillators is discussed.European Physical Journal C 01/2013; 73:2276. · 3.63 Impact Factor -
Article: Random coincidence of $2\nu2\beta$ decay events as a background source in bolometric $0\nu2\beta$ decay experiments
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ABSTRACT: Two neutrino double $\beta$ decay can create irremovable background even in high energy resolution detectors searching for neutrinoless double $\beta$ decay due to random coincidence of $2\nu2\beta$ events in case of poor time resolution. Possibilities to suppress this background in cryogenic scintillating bolometers are discussed. It is shown that the present bolometric detector technologies enable to control this form of background at the level required to explore the inverted hierarchy of the neutrino mass pattern, including the case of bolometers searching for the neutrinoless double $\beta$ decay of $^{100}$Mo, which is characterized by a relatively short two neutrino double $\beta$ decay half-life.01/2013; -
Article: Search for $\alpha$ decay of $^{151}$Eu to the first excited level of $^{147}$Pm using underground $\gamma$-ray spectrometry
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ABSTRACT: The alpha decay of $^{151}$Eu to the first excited level of $^{147}$Pm ($J^\pi = 5/2^+$, $E_{exc}=91.1$ keV) was searched for at the HADES underground laboratory ($\approx 500$ m w.e.). A sample of high purity europium oxide with mass of 303 g and a natural isotopic composition has been measured over 2232.8 h with a high energy resolution ultra-low background n-type semi-planar HPGe detector (40 cm$^3$) with sub-micron deadlayer. The new improved half-life limit has been set as $T_{1/2} \geq 3.7\times 10^{18}$ yr at 68% C.L. Possibilities to improve the sensitivity of the experiment, which is already near the theoretical predictions, are discussed. New half-life limit for $\alpha$ decay of $^{153}$Eu is also set as $T_{1/2} \geq 5.5\times 10^{17}$ yr.01/2013; -
Article: First search for double-beta decay of 184Os and 192Os
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ABSTRACT: A search for double-beta decay of osmium has been realized for the first time with the help of an ultra-low background HPGe gamma detector at the underground Gran Sasso National Laboratories of the INFN (Italy). After 2741 h of data taking with a 173 g ultra-pure osmium sample limits on double-beta processes in 184Os have been established at the level of T_{1/2} about 10^{14}-10^{17} yr. Possible resonant double-electron captures in 184Os were searched for with a sensitivity T_{1/2} about 10^{16} yr. A half-life limit T_{1/2} > 5.3 10^{19} yr was set for the double-beta decay of 192Os to the first excited level of 192Pt. The radiopurity of the osmium sample has been investigated and radionuclides 137Cs, 185Os and 207Bi were detected in the sample, while activities of 40K, 60Co, 226Ra and 232Th were limited at the mBq/kg level.European Physical Journal A 01/2013; 49:24. · 2.19 Impact Factor -
Article: Scintillation properties and internal background study of 40Ca100MoO4 crystal scintillators for neutrino-less double beta decay search
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ABSTRACT: Scintillation properties and radioactive contamination of calcium molybdate scintillating crystals depleted in 48Ca and enriched in 100Mo (40Ca100MoO4 ) have been studied to prepare a 100Mo-based neutrinoless double beta decay experiment. The prospects of a neutrinoless double beta decay experiment using 40Ca100MoO4 crystals are discussed.IEEE Transactions on Nuclear Science 10/2012; 59(5):2214 - 2218. · 1.45 Impact Factor -
Article: Response of CdWO4 crystal scintillator for few MeV ions and low energy electrons
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ABSTRACT: The response of a CdWO4 crystal scintillator to protons, alpha particles, Li, C, O and Ti ions with energies in the range 1 - 10 MeV was measured. The non-proportionality of CdWO4 for low energy electrons (4 - 110 keV) was studied with the Compton Coincidence Technique. The energy dependence of the quenching factors for ions and the relative light yield for low energy electrons was calculated using a semi-empirical approach. Pulse-shape discrimination ability between gamma quanta, protons, alpha particles and ions was investigated.08/2012; -
Article: AMoRE experiment: a search for neutrinoless double beta decay of 100 Mo isotope with 40 Ca 100 MoO 4 cryogenic scintillation detector
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ABSTRACT: AMoRE (Advanced Mo based Rare process Experiment) collaboration is going to use calcium molybdate crystals as cryogenic scintillation detector in a search for neutrinoless DBD of 100Mo isotope. Simultaneous detection of phonons and light will be used to reject internal background. A FWHM resolution of 0.2% in the phonon channel has been achieved with a 0.5 cm3 crystal. Several 40Ca100MoO4 crystals (» 0.5 kg) have been developed from enriched 100Mo and depleted 40Ca materials. The light yield of these crystals has been shown to be comparable with reference CaMoO4 scintillators for temperatures ranging down to 8 K. The content of dangerous radioisotopes in the crystals is under measurement. The projected sensitivity of the experiment for a 250 kg ´ years exposure is lim T1/2 ~ 3 * 10^26 years, which corresponds to the effective Majorana neutrino mass 〈mn〉 ~ 0.02 – 0.06 eV.Journal of Physics Conference Series 08/2012; 375:042023. -
Article: Searches for neutrinoless resonant double electron captures at LNGS
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ABSTRACT: Several experiments were performed during last years at underground (3600 m w.e.) Laboratori Nazionali del Gran Sasso (LNGS) of the INFN (Italy) to search for resonant 2$\varepsilon0\nu$ captures in 96Ru, 106Cd, 136Ce, 156Dy, 158Dy, 180W, 184Os, 190Pt with the help of HP Ge semiconductor detectors, and ZnWO4 and 106CdWO4 crystal scintillators. No evidence for r-2$\varepsilon0\nu$ decays was found, and only T_{1/2} limits were established in the range of 10^{14}-10^{21} yr.Journal of Physics Conference Series 07/2012; 375:042024. -
Article: Ultrapurification of archaeological lead
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ABSTRACT: Based on purification efficiency calculations for lead distillation, we developed a combined process for the ultrapurification of archaeological lead. We obtained pilot amounts of high-purity archaeological lead and PbO with the following contents of detrimental impurities: U, <2 ppb; Th, <1 ppb; Ni, Cu, Fe, Si, Ti, Mg, Al, Mn, Cr, V, Co, < 0.1 ppm; K, Ca, Zn, Cd, Ag, Sb, < 1 ppm. Lead of such purity can be used in low-background experiments as a protective shield material and in the growth of low-background PbWO4 and PbMoO4 scintillator crystals. From an isotope ratio, we were able to identify the origin of the archaeological lead.Inorganic Materials 04/2012; 47(6):645-648. · 0.41 Impact Factor -
Article: Search for double- decays of 96Ru and 104Ru by ultra-low background HPGe spectrometry
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ABSTRACT: A search for double-b \beta processes in 96Ru and 104Ru was realized in the underground Gran Sasso National Laboratories of the INFN (Italy) with the help of ultra-low background HPGe g \gamma spectrometry. After 158h of data taking with 473g ruthenium sample, new improved limits on double-beta processes in 96Ru have been established on the level of 1018-1019yr. For the first time the double-beta decay of 104Ru to the 2+ 1 excited level of 104Pd has been restricted as T 1/2 > 3.5×1019 yr.European Physical Journal A 04/2012; 42(2):171-177. · 2.19 Impact Factor -
Article: Search for double-β decay processes in 106Cd with the help of a 106CdWO4 crystal scintillator
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ABSTRACT: A search for double beta processes in Cd-106 was carried out at the Gran Sasso National Laboratories of the INFN (Italy) with the help of a (CdWO4)-Cd-106 crystal scintillator (215 g) enriched in Cd-106 up to 66%. After 6590 h of data taking, new improved half-life limits on the double beta decay processes in Cd-106 were established at the level of 10(19)-10(21) yr; in particular, T-1/2(2 nu epsilon beta) >= 2.1 x 10(20) yr, T-1/2(2 nu epsilon beta+) >= 4.3 x 10(20) yr, and T-1/2(0 nu 2 epsilon) >= 1.0 x 10(21) yr. The resonant neutrinoless double-electron captures to the 2718-, 2741-, and 2748-keV excited states of Pd-106 are restricted to T-1/2(0 nu 2K) >= 4.3 x 10(20) yr, T-1/2(0 nu KL1) >= 9.5 x 10(20) yr, and T-1/2(0 nu KL3) >= 4.3 x 10(20) yr, respectively (all limits at 90% confidence level). A possible resonant enhancement of the 0 nu 2 epsilon processes is estimated in the framework of the quasiparticle random phase approximation (QRPA) approach. Radioactive contamination of the (CdWO4)-Cd-106 crystal scintillator is reported.Physical Review C 04/2012; 85(4):044610. · 3.31 Impact Factor -
Article: Heat flow of the Earth and resonant capture of solar 57Fe axions
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ABSTRACT: In a very conservative approach, supposing that all heat flow of the Earth is exclusively due to resonant capture inside the Earth of axions emitted by 57Fe nuclei on Sun, we obtain limit on the mass of hadronic axion: m a < 1.8 keV. Taking into account release of heat from decays of 40K, 232Th, 238U inside the Earth, this estimation could be improved to the value: m a < 1.6 keV. Both the values are less restrictive than limits set in devoted experiments to search for 57Fe axions (m a < 216–745 eV), but are much better than limits obtained in experiments with 83Kr (m a < 5.5 keV) and 7Li (m a < 13.9–32 keV).Kinematics and Physics of Celestial Bodies 04/2012; 25(2):102-106. · 0.36 Impact Factor -
Article: Search for Li-7 solar axions using resonant absorption in LiF crystal: Final results
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ABSTRACT: The resonance excitation of the Li-7 nuclei in a LiF crystal with mass of 553 g by hypothetical axions emitted in the deexcitation of the Li-7 nuclei in the Sun was searched for deep underground at the Gran Sasso National Laboratories (LNGS) of INFN (3600 m we.). The data collected with a low background HP Ge detector 244 cm(3) during 4044h have allowed us to set the limit on the axion mass: m(a) < 8.6 key (90% CL.) which is the best one for the Li-7 solar axions to-date. (C) 2012 Elsevier B.V. All rights reserved.Physics Letters B 01/2012; 711(1):41-45. · 3.95 Impact Factor -
Conference Proceeding: Search for double beta decay of Cd-106 by using isotopically enriched (CdWO4)-Cd-106 crystal scintillator
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ABSTRACT: A search for double beta processes in Cd-106 was carried out at the Gran Sasso National Laboratories of the INFN (Italy) by using a CdWO4 crystal scintillator (mass of 215 g) enriched in Cd-106 up to 66%. After 6590 h of data taking, half-life limits on double beta processes in Cd-106 were set at level of 10(19) - 10(21) yr. A possible resonant enhancement of the 0 nu 2 epsilon processes has also been estimated in the framework of the QRPA approach.12TH INTERNATIONAL CONFERENCE ON TOPICS IN ASTROPARTICLE AND UNDERGROUND PHYSICS (TAUP 2011), PTS 1-6; 01/2012 -
Article: Experimental research of double beta decay of atomic nuclei
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ABSTRACT: Results of several double beta decay experiments, performed with the help of low background crystal scintillators, are presented. In particular, the half-life value of the two-neutrino double beta decay of 116-Cd has been measured as 2.9 10^{19} yr, and the new half-life limit on the neutrinoless double beta decay of 116-Cd has been established as >1.7 10^{23} yr at 90%, which corresponds to a restriction on the neutrino mass <1.7 eV. New half-life bounds on the level of 10^{17}-10^{21} yr were set for double beta processes in 64-Zn, 70-Zn, 106-Cd, 108-Cd, 114-Cd, 136-Ce, 138-Ce, 142-Ce, 160-Gd, 180-W, and 186-W by using low-background CdWO4, GSO, and ZnWO4 crystal scintillators. The claim of discovery of the neutrinoless double beta decay of 76-Ge [Mod. Phys. Lett. A 16 (2001) 2409] was analyzed. The demands of the future high sensitivity double beta decay experiments, aiming to observe the neutrinoless double beta decay or to advance restrictions on the neutrino mass to < 0.01 eV, were considered. Requirements for their sensitivity and discovery potential were formulated. Two projects of double beta experiments with a sensitivity on the level of 10^{26}-10^{27} yr (CAMEO and CARVEL projects) were discussed. Scintillation properties and radioactive contamination of CaWO4, ZnWO4, CdWO4, PbWO4, GSO(Ce), CeF3, yttrium-aluminum garnet doped with neodymium (YAG:Nd) crystal scintillators were studied. Applicability of these scintillators to search for double beta decay was discussed.12/2011;
Top Journals
Institutions
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2013
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Università degli Studi di Roma "La Sapienza"
- Department of Physics
Roma, Latium, Italy -
University of Rome Tor Vergata
- Dipartimento di Fisica
Roma, Latium, Italy
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2009–2012
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National Academy of Sciences of Ukraine
- • Institute for Nuclear Research
- • Institute of Scintillation Materials
Kiev, Misto Kyyiv, Ukraine
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2001–2012
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Kiev Institute for Nuclear Research
Kiev, Misto Kyyiv, Ukraine
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2010
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Texas A&M University
College Station, TX, USA
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2006
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Institute of General and Inorganic Chemistry
Kiev, Misto Kyyiv, Ukraine -
Joint Institute for Nuclear Research
Dubna, Moskovskaya, Russia
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2000
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Università degli Studi di Firenze
Florence, Tuscany, Italy
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1995–1996
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Ukrainian Academy of Agrarian Sciences
Kiev, Misto Kyyiv, Ukraine
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