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[en] Polarization of superfluid helium (HeII) during the second sound excitation, which was observed by Rybalko (Fiz. Nizk. Temp. 30, 1321 (2004), has been explained as the inertial polarization of a dielectric medium. For the second sound waves, the acceleration is chosen as the time derivative of the relative velocity of the normal component with respect to the superfluid one
[en] Originally, random matrix theory (RMT) was designed by Wigner to deal with the statistics of eigenvalues and eigenfunctions of complex many-body quantum systems in 1950s. During the last two decades, the RMT underwent an unexpected and rapid development: The RMT has been successfully applied to an ever increasing variety of physical problems, and it has become an important tool to attack many-body problems. In this contribution I briefly outline the development of the RMT and introduce its basics. Its application to the decay out of a superdeformed band and a comparison of the approach used in Ref. 34 with that proposed by Vigezzi et al are presented. Current theoretical activities on the decay out problem are reviewed, and the influence of the degree of chaoticity of the normally deformed states on the decay out intensity is examined systematically. (author)
[en] We present a method to determine the magnitude of the uncorrelated background distribution obtained with the event mixing technique, through the simultaneous observation of the projectile elastic scattering in different detectors, which correspond to random coincidences. The procedure is tested with α-d angular correlation data from the 6Li+59Co reaction at Elab=29.6MeV. We also show that the method can be applied using the product of singles events, when singles measurements are available.
[en] This paper provides a brief history of the evolution of the Berkeley experiments on macroscopic quantum effects in superfluid helium. The narrative follows the evolution of the experiments proceeding from the detection of single vortex lines to vortex photography to quantized circulation in 3He to Josephson effects and superfluid gyroscopes in both 4He and 3He
[en] The exclusive cross section for the breakup of 6Li by 209Bi has been measured at Elab=40 and 36 MeV. Sequential breakup, via the resonant state (3+) of 6Li in the continuum, dominates the total breakup cross section. The two sequential breakup peaks corresponding to the above resonant state, in both alpha and deuteron spectra, were found to be asymmetric. Continuum discretized coupled-channel (CDCC) calculations show the influence of both the Coulomb as well as the nuclear field on breakup.
[en] Changing land use is one of the primary causes of increased sedimentation and nturient levels in aquqatic systems, resulting in contamiantion and reduction of biodiversity. Detecting and quantifying these inputs is the first step of remediation, to enable targeted reduction of transport processes into waterways from human impacted land surfaces. More recently, stable isotope analyses are being used as a detection and quantification tool in aquatic environments. Carbon and nitrogen isotopes of sediments, algae and invertebrates from aquatic systems can be used as proxies to record both short and long term enviornmental cahgne. Excess nutrients derived from urbanization, industry, forestry, farming and agriculture increase the bio-availability of nitrogen to aquatic organisms, changing their natural 15N isotopic signatures. Allochthonous (terrestrial) input from soil destabilization and human activity in surrounding catchments changes the 13C isotope ratios and increases the C:N ratio of sediments. Heavy metal and other organic pollutants can also be used to indicate urbanization and industrial contamination. The comined use of carbon and nitrogen isotopes, C:N ratios and heavy metals are powerful environmental monitoring tools which are useful indicators of source and transport pathways of terrestrial derive dmaterial and anthropogenic pollutants into strams, rivers and estuaries. (author). 56 refs., 10 figs., 3 tabs
[en] Due to high neutron absorption cross section, boron and its compounds find extensive application in the nuclear industry. The Materials Processing Division have developed processes for the production of boron, its compounds and components for application as control/shutoff rods in nuclear reactors, sensors for neutron counting, shapes for neutron shielding etc. This article traces the research and development activities, carried out on boron based neutron absorber materials
[en] We study a twisted vortex bundle where quantized vortices form helices circling around the axis of the bundle in a 'force-free' configuration. Such a state is created by injecting vortices into a rotating vortex-free superfluid. Using continuum theory we determine the structure and the relaxation of the twisted state. This is confirmed by numerical calculations. We also present experimental evidence of the twisted vortex state in superfluid 3He-B
[en] The frequencies of the 2S-3S two-photon transition for the stable lithium isotopes were measured by cavity-enhanced Doppler-free laser excitation that was controlled by a femtosecond frequency comb. The resulting values of 815 618 181.57(18) and 815 606 727.59(18) MHz, respectively, for 7Li and 6Li are in agreement with previous measurements but are more accurate by an order of magnitude. There is still a discrepancy of about 11.6 and 10.6MHz from the latest theoretical values. This is comparable to the uncertainty in the theoretical calculations, while uncertainty in our experimental values is more than a hundred-fold smaller. More accurate theoretical calculation of the transition frequencies would allow extraction of the absolute charge radii for these stable isotopes, which in turn could improve nuclear charge radii values for the unstable lithium isotopes