2,959 research outputs found
Off-line studies of the laser ionization of yttrium at the IGISOL facility
A laser ion source is under development at the IGISOL facility, Jyvaskyla, in
order to address deficiencies in the ion guide technique. The key elements of
interest are those of a refractory nature, whose isotopes and isomers are
widely studied using both laser spectroscopic and high precision mass
measurement techniques. Yttrium has been the first element of choice for the
new laser ion source. In this work we present a new coupled dye-Ti:Sapphire
laser scheme and give a detailed discussion of the results obtained from laser
ionization of yttrium atoms produced in an ion guide via joule heating of a
filament. The importance of not only gas purity, but indeed the baseline vacuum
pressure in the environment outside the ion guide is discussed in light of the
fast gas phase chemistry seen in the yttrium system. A single laser shot model
is introduced and is compared to the experimental data in order to extract the
level of impurities within the gas cell.Comment: 18 pages submitted to NIM
Stable branches of a solution for a fermion on domain wall
We discuss the case when a fermion occupies an excited non-zero frequency
level in the field of domain wall. We demonstrate that a solution exists for
the coupling constant in the limited interval . We
show that indeed there are different branches of stable solution for in
this interval. The first one corresponds to a fermion located on the domain
wall (). The second branch, which belongs to the interval
, describes a polarized fermion off the domain
wall. The third branch with describes an excited antifermion in
the field of the domain wall.Comment: 15 pages, 7 figures, references adde
Phase behavior and orientational ordering in block copolymers doped with anisotropic nanoparticles
A molecular field theory and coarse-grained computer simulations with dissipative particle dynamics have been used to study the spontaneous orientational ordering of anisotropic nanoparticles in the lamellar and hexagonal phases of diblock copolymers and the effect of nanoparticles on the phase behavior of these systems. Both the molecular theory and computer simulations indicate that strongly anisotropic nanoparticles are ordered orientationally mainly in the boundary region between the domains and the nematic order parameter possesses opposite signs in adjacent domains. The orientational order is induced by the boundary and by the interaction between nanoparticles and the monomer units in different domains. In simulations, sufficiently long and strongly selective nanoparticles are ordered also inside the domains. The nematic order parameter and local concentration profiles of nanoparticles have been calculated numerically using the model of a nanoparticle with two interaction centers and also determined using the results of computer simulations. A number of phase diagrams have been obtained which illustrate the effect of nanoparticle selectivity and molar fraction of the stability ranges of various phases. Different morphologies have been identified by analyzing the static structure factor and a phase diagram has been constructed in coordinates' nanoparticle concentration-copolymer composition. Orientational ordering of even a small fraction of nanoparticles may result in a significant increase of the dielectric anisotropy of a polymer nanocomposite, which is important for various applications
The possibility of increasing cadets’ physical fitness level of the educational organizations of the Ministry of Internal Affairs of Russia with the help of optimal training effects via crossfit
Actually, the studies indicate a negative decline dynamics of the main indicators of the physical development and health of the modern young people receiving higher education. In our studies, it was found that the existing physical training programs are not able to provide the optimal level of functional readiness of the military students and officers of the military universities as needed to perform the professional task
Criteria for effective sports selection in judo schools - on example of sportsmanship’s progress of young judo athletes in Russian Federation
Analysis of scientific researches points at significant discrepancies in opinions about criteria of sports selection in Judo schools and structure of junior athletes’ training activity. The purpose of the research is to fulfil of different methodic of young people’s selection and dynamic of their future competition functioning’s sports result
Topics of doctoral and postdoctoral dissertations devoted to judo in period 2000-2016 - the overall analysis of works of Russian experts
The aim of this article are the preferences topics of doctoral and postdoctoral theses on judo defended in Russian Federation universities in the period 2000-201
Computation of the radiation amplitude of oscillons
The radiation loss of small amplitude oscillons (very long-living, spatially
localized, time dependent solutions) in one dimensional scalar field theories
is computed in the small-amplitude expansion analytically using matched
asymptotic series expansions and Borel summation. The amplitude of the
radiation is beyond all orders in perturbation theory and the method used has
been developed by Segur and Kruskal in Phys. Rev. Lett. 58, 747 (1987). Our
results are in good agreement with those of long time numerical simulations of
oscillons.Comment: 22 pages, 9 figure
Heavy Superheated Droplet Detectors as a Probe of Spin-independent WIMP Dark Matter Existence
At present, application of Superheated Droplet Detectors (SDDs) in WIMP dark
matter searches has been limited to the spin-dependent sector, owing to the
general use of fluorinated refrigerants which have high spin sensitivity. Given
their recent demonstration of a significant constraint capability with
relatively small exposures and the relative economy of the technique, we
consider the potential impact of heavy versions of such devices on the
spin-independent sector. Limits obtainable from a -loaded SDD
are estimated on the basis of the radiopurity levels and backgrounds already
achieved by the SIMPLE and PICASSO experiments. With 34 kgd exposure,
equivalent to the current CDMS, such a device may already probe to below
10 pb in the spin-independent cross section.Comment: 9 pages, 4 figures, accepted Phys. Rev.
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