A measurement of the neutron lifetime using the method of storage of ultracold neutrons and detection of inelastically up-scattered neutrons

AbstractWe present estimations of systematic corrections and results of their experimental studies for our neutron lifetime experiment carried out in 2008–2010 at ILL. Taking into account these systematic corrections, we reduce the data of three independent sets of measurements (obtained during period 2008–2010) performed with different energy spectra of ultracold neutrons (UCNs) at different trap temperatures to the mean neutron lifetime value equal to 880.2(1.2) s

Special features of the 9^9Be→\to2He fragmentation in emulsion at an energy of 1.2~A~GeV

The results of investigations of the relativistic $^9$Be nucleus fragmentation in emulsion which entails the production of two He fragments of an energy of 1.2~A~GeV are presented. The results of the angular measurements of the $^9$Be$\to$2He events are analyzed. The $^9$Be$\to^8$Be+n fragmentation channel involving the $^8$Be decay from the ground (0$^+$) and the first excited (2$^+$) states to two $\alpha$ particles is observed to be predominant.Comment: 10 pages, 6 figures, conference: Conference on Physics of Fundamental Interactions, Moscow, Russia, 5-9 Dec 2005 (Author's translation

Clustering in light nuclei in fragmentation above 1 A GeV

The relativistic invariant approach is applied to analyzing the 3.3 A GeV $^{22}$Ne fragmentation in a nuclear track emulsion. New results on few-body dissociations have been obtained from the emulsion exposures to 2.1 A GeV $^{14}$N and 1.2 A GeV $^{9}$Be nuclei. It can be asserted that the use of the invariant approach is an effective means of obtaining conclusions about the behavior of systems involving a few He nuclei at a relative energy close to 1 MeV per nucleon. The first observations of fragmentation of 1.2 A GeV $^{8}$B and $^{9}$C nuclei in emulsion are described. The presented results allow one to justify the development of few-body aspects of nuclear astrophysics.Comment: 7 pages, 8 figures, 3 tables, Nuclear Physics in Astrophysics-2, 16-20 May, 2005 (ATOMKI), Debrecen, Hungar

Electromagnetic dissociation of relativistic 8^8B nuclei in nuclear track emulsion

Experimental data on fragmentation channels in peripheral interactions of $^8$B nuclei in nuclear track emulsions are presented. A detailed analysis made it possible to justify selections of events of the electromagnetic-dissociation process $^8$B $\to^7$Be + \emph{p} and to estimate its cross section. Events of $^{10}$C peripheral dissociation that were observed in the same exposure are described.Comment: 12 pages, 10 figures, 4 tables, Published in Phys.Atom.Nucl.72:690-701,200

Исследование реакции тромбоцитов на a-C:H:SiOx покрытие, полученное методом плазмохимического осаждения с использованием импульсного биполярного смещения

Aim. To study platelet adhesion to a-C:H:SiOx film on titanium in an in vitro experiment to evaluate its antithrombogenic potential.Materials and methods. Thin (less than 1 μm) a-C:H:SiOx films were deposited on VT-6 titanium plates with a size of 10 × 10 mm2 and a thickness of 0.2 mm using a vacuum ion-plasma unit using pulsed bipolar bias. The surface roughness was evaluated according to GOST 2789-73 using an atomic force microscope. The test samples were cultured at 37 °C for 30 min in platelet-rich human blood plasma, prepared for scanning electron microscopy, after which the distribution density of blood plates adhering to the test coating was calculated.Results. With the same roughness index of the studied a-C:H:SiOx samples, the film decreased 116 times (in comparison with untreated titanium) the platelet count per 1 mm2 of the surface.Conclusion. The deposition of a-C:H:SiOx thin film on the surface of VT-6 titanium alloy by PACVD method using pulsed bipolar bias significantly reduces the distribution density of platelets in comparison with an untreated metal surface. In vitro data suggest a significant antithrombogenic potential of this type of coating on the surface of devices in contact with blood.Цель. Изучить в эксперименте in vitro адгезию тромбоцитов к a-C:H:SiOx пленке на титане для оценки ее атромбогенного потенциала.Материалы и методы. Тонкие (менее 1 мкм) a-C:H:SiOx пленки наносили на титановые пластины марки ВТ-6 размером 10 × 10 мм2 и толщиной 0,2 мм с помощью вакуумной  ионно-плазменной установки с использованием импульсного биполярного смещения.  Шероховатость поверхности оценивали согласно ГОСТ 2789-73 с помощью атомно-силового микроскопа. Исследуемые образцы культивировали при 37 °C в течение 30 мин в плазме крови человека, обогащенной тромбоцитами, подготавливали для сканирующей электронной микроскопии, после чего подсчитывали плотность  распределения кровяных пластинок, адгезирующих к исследуемому покрытию.Результаты. При одинаковом индексе шероховатости исследуемых образцов a-C:H:SiOx пленка в 116 раз снижала (в сравнении с необработанным титаном) количество  тромбоцитов на 1 мм2 поверхности.Заключение. Формирование на поверхности титанового сплава ВТ-6 тонкой пленки состава a-C:H:SiOx методом плазмохимического осаждения с использованием  импульсного биполярного смещения значительно снижает плотность распределения  тромбоцитов в сравнении с необработанной металлической поверхностью. Полученные in vitro данные предполагают существенный атромбогенный потенциал данного вида покрытий на поверхности устройств, контактирующих с кровью

Fragmentation of relativistic nuclei in peripheral interactions in nuclear track emulsion

The technique of nuclear track emulsions is used to explore the fragmentation of light relativistic nuclei down to the most peripheral interactions - nuclear "white" stars. A complete pattern of therelativistic dissociation of a $^8$B nucleus with target fragment accompaniment is presented. Relativistic dissociation $^{9}$Be$\to2\alpha$ is explored using significant statistics and a relative contribution of $^{8}$Be decays from 0$^+$ and 2$^+$ states is established. Target fragment accompaniments are shown for relativistic fragmentation $^{14}$N$\to$3He+H and $^{22}$Ne$\to$5He. The leading role of the electromagnetic dissociation on heavy nuclei with respect to break-ups on target protons is demonstrated in all these cases. It is possible to conclude that the peripheral dissociation of relativistic nuclei in nuclear track emulsion is a unique tool to study many-body systems composed of lightest nuclei and nucleons in the energy scale relevant for nuclear astrophysics.Comment: 15 pages, 4 figures, 4 tables, conference: Relativistic nuclear physics: from Nuclotron to LHC energies, Kiev, June 18-22, 200