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The main aim of the present manuscript is analysis, and simulation different type silicene nanoribbons with edges modified by hydrogen, used in modern semiconductors. The focus of this paper is investigation the main characteristic and parameters of doping a Bi atom in the unit cell of silicene nanoribbons. The experiments are carried out with external electric field with intensity 0.1V/A. In our study we used Angstrom (A) for distance measurement, because the approximate orbital diameter of one electron in a hydrogen atom is smaller, the atomic lattice spacing in most crystals is of the same order. On the base of the conducted classification we proposed and studied two different atom configuration - the top configuration and the valley configuration. In our investigation we used density functional theory (DFT) and applied methods for synthesis and calculation of the formation energy of the doped system. The obtained result show that the optimal configuration is the top configuration. On another hand we calculated the state densities of the doped configurations and energy band of investigated structures. The contributions of the partial states Si(s), Si(p), Bi(s), Bi(p) are also analyzed. [ABSTRACT FROM AUTHOR]

The departure of atoms from the surface of the condensed phase leads to the appearance of a flow of atoms flying not only from the surface but also, due to collisions of atoms, leads to the reverse flow of atoms from the gas phase to the condensed phase, and to the formation of nanoclusters that affect the flow of gas. In this regard, the first collisions of atoms after the departure from the surface of the condensed phase play an important role. In the present paper, the simultaneous flight of three atoms from the bounded surface of the condensed phase is considered. The first and second collisions of atoms were determined depending on the size of the evaporation area. The regularities for the densities of the distributions of collisions of atoms over the surface and the free path lengths, as well as their average values, are established. The calculations were performed using the direct Monte Carlo simulation. The atoms were represented as rigid spheres, so after the collision the atoms instantly flew apart. In each computer experiment, at least 180,000,000 triples of atoms were played. [ABSTRACT FROM AUTHOR]

The paper investigates the features of the photoconductivity of silicon with multiply charged nanoclusters of manganese atoms. It is shown that in such samples anomalously high impurity photoconductivity is observed in the spectral region λ = 1.8 - 3 µm. It was also shown that such samples have a giant residual photoconductivity. This material p-Si with nanoclusters of manganese atoms is a very promising material not only for the development of fundamentally new photovoltaic devices, but also for the creation of efficient solar cells operating in the infrared region. [ABSTRACT FROM AUTHOR]

This paper is an abstract of a greater volume of work more than 30 years in formation. It is a thought experiment. In order to present certain concepts, statements are made without supporting scientific observations which would require a substantial manuscript to present. This paper defines a new fabric for space and hypothesizes that matter is formed from this fabric through the agency of Black Holes. Dark sound is theorized. As a consequence of this hypothesis a new model for the origin of the universe is given including new definitions for Black Holes, Dark Matter, and Dark Energy. Neutral electricity, cosmic planes and sub planes are defined. New processes for the coalescing of atoms, the rotation of planets and the observed phenomena of Cosmic Fire are given. Gravity is defined as the result of magnetism and chemical bonds between structures. [ABSTRACT FROM AUTHOR]

The paper shows the effect of nitrogen and sulfur-containing additives on the antioxidant and antimicrobial properties of oil products. The geometrical and electronic characteristics of the molecules were calculated and the "structure - manifested property" relationship has been established. [ABSTRACT FROM AUTHOR]

The various roles that theoretical work plays in the evolution of physics are reviewed, and classified. The need for properly justified uncertainty estimates to accompany theoretical atomic and molecular data is discussed. A new set of guidelines is described for the conditions under which uncertainty estimates should be included in published work. [ABSTRACT FROM AUTHOR]

In this paper we studied an one-dimensional array of atoms coupled to a single-mode waveguide. The formation of polaritonic states is considered in infinite system with and without account for chiral interactions. The effect of diagonal disorder was studied numerically in a finite atomic array. We showed that in the presence of disorder localized states were observed in a symmetrically coupled atoms along with delocalized states. With increase of the degree of directionality the delocalized states evolved into the end-of-array localized states, while the considered localized states survive till particular degree of directionality. [ABSTRACT FROM AUTHOR]

Described by simple atomic theory published in 1913 by Niels Bohr, spectral lines in the radio range arising from transitions between large principal quantum numbers of atoms have proved to be useful tools for astronomers and physicists. Called “radio recombination lines” because of the wavelength range where most are observed, they are usually easy to detect, give unique information about astronomical objects, and facilitate the study of physical effects in environments that cannot be created in terrestrial laboratories. Observations have revealed unexpected results regarding thermodynamic populations of the principal quantum levels and about pressure broadening in astronomical environments. Detections of large-n lines, such as the n = 1006→1010 absorption line of interstellar carbon, show the existence of atoms with classical diameters of about 0.1 mm, the thickness of a sheet of typing paper. This paper briefly discusses observations of Stark broadening reported by Bell et al. in 2002. [ABSTRACT FROM AUTHOR]

In this paper, the ultrafast dissociation following Cl 2p core–shell excitation into the 10a1* antibonding orbital in CH2Cl2 and CD2Cl2 molecules is studied. It is observed the presence of atomic Auger lines associated to the decay of dissociated Cl* atoms. The choice of CH2Cl2 and CD2Cl2 molecules to study the competition between the atomic and molecular Auger decays, allow us to probe nuclear dynamics and electron relaxation occurring on a comparable time scale, keeping other parameters identical. [ABSTRACT FROM AUTHOR]

The antiproton celebrates its 50th birthday this year. Although its existence had been suspected since the discovery of the positron in 1932, there was still doubt in some quarters that such a companion particle to the proton could exist. I will try to trace the scientific history of the antiproton from that time to the publication of the definitive paper by Chamberlain, Segrè, Wiegand and Ypsilantis in November 1955, with a brief look at what happened next. The narrative will be supplemented with thoughts and opinions of some of the main actors, both at the time and in retrospect. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]

It has now been firmly established from both theoretical calculations and observations, that the exospheres of the terrestrial planets have extended coronae of translational energetic oxygen atoms. The current model generally accepted as the source of these hot atoms is the dissociative recombination of O[SUP +,SUB 2], that is, O[SUP +,SUB 2] + e[SUP-] → O* + O* where the product O* atoms are translationally energetic. The determination of the extent of this population of superthermal atoms is an important endeavor. The present paper considers a simple model based on the Boltzmann equation for the energy and altitude dependence of the oxygen atom distribution function. The density and temperature distributions are determined with this distribution. [ABSTRACT FROM AUTHOR]

Atom is a concept that students meet with in both physics and chemistry. The difficulty of the explication of this concept is that it is a highly abstract construct; the atom can not be perceived by the human senses and can not be seen by means of simple instruments. Teachers use different, more or less suitable models, analogies and metaphors during the interpreting of this concept (e.g. electron cloud, „fuzzy“ electron, atomic nucleus, etc.). However, pupils often create their own models in their minds and their ideas may differ considerably from the idea of the atom that their teachers have. In this respect, textbooks also play an important role, but in various physics textbooks there are presented different models of atoms. In the paper, we present the most common models of atoms used in physics textbooks for lower secondary schools in the Czech Republic and show their possible influence on the formation or the strengthening of some pupils´misconceptions. The frequency of these misconceptions is exemplified by a study we carried out in the Czech Republic, involving a set of 170 of 15-year-old pupils from seven lower secondary schools. All participants of this study were quizzed on their understanding of the concept of an atom using a one-tier diagnostic test which included some of the most common misconceptions about atoms that have been identified in foreign education research. [ABSTRACT FROM AUTHOR]

Every particle has its counterpart – an anti – particle. Any amount of anti – particle, when in contact with particle, will annihilate itself with particle of the same amount to produce energy in a flash. It is the space – time symmetry that makes particle’s Universe exactly the same as anti – particle’s Universe. On a macroscopic scale, both the Universe pair looks exactly the same. Similar thing happens in microscopic scale, it is the charge symmetry that makes atom and anti – atom exactly the same. The Universe pair and atom pair are observer dependent realism only. An observer made of particle will see exactly opposite to the observer made of anti – particle – the observer pair sees the opposite reality which makes reality as relative. In this paper, I will discuss space – time symmetry on a macroscopic scale and charge symmetry on a microscopic scale. [ABSTRACT FROM AUTHOR]

Atomism plays an important role in the history of human thought. It can be traced back from Democritus atomos in the 500 BC to particle physics and quantum theory in the 21st century. However, as it being rejected and developed in the course of history of science, it still brings the fundamental question that perplexes physicists. It gives the views that the world is eternal; that the laws of nature is immutable and eternal therefore all phenomena can be determined through the laws and that there is no reality behind the quantum world. In this paper, we shall briefly describe all these three views on the nature of the physical world or universe and this include on the nature of matter. Then, we shall explain our stand on those conceptions based on the Ash'arites atomistic conception of the physical world. We hope this paper can shed a light on several fundamental issues in the conception of the universe and gives the proper response to them. [ABSTRACT FROM AUTHOR]

The first ever Compton profile study of polycrystalline ZnBr2 is presented in this paper. The measurement of polycrystalline sample of ZnBr2 is performed using 59.54 keV gamma-rays emanating from an 241Am radioisotope. Theoretical calculations are performed following the Ionic model calculations for a number of configurations Zn+xBr2-x/2 (0.0≤x≤2.0 in step of 0.5) utilizing free atom profiles. The ionic model suggest transfer of 2.0 electrons from 4 s state of Zn to 4 p state of two Br atoms. The autocorrelation function B(z) is also derived from experiment and the most favoured ionic valence Compton profiles. [ABSTRACT FROM AUTHOR]

Neither the theory nor the interpretation of Extended X-Ray-Absorption Fine-Structure (EXAFS) spectroscopy requires assumptions of crystalline symmetry or periodicity. As a result, EXAFS is a tool applied to a wide range of scientific disciplines and to a wide variety of experimental systems. A simple enumeration of the atoms in the coordination environment of the absorber is often the primary goal of an EXAFS experiment. There are, however, a number of pitfalls in the way of an accurate determination of coordination number (CN). These include statistical limitations of the EXAFS fitting problem, empirical effects due to sample preparation, and the assumptions made about the physical structure surrounding the absorber in the course of data analysis. In this paper we examine several of these pitfalls and their effects upon the determination of CN. Where possible, we offer suggestions for avoiding or mitigating the pitfalls. We hope this paper will help guide the general EXAFS practitioner through the difficult chore of accurately determining CN. © 2007 American Institute of Physics [ABSTRACT FROM AUTHOR]

The paper presents a comprehensive study of the quantitative phase composition of Portland cement using the Rietveld refinement technique, a model description of its phases depending on the curing time (0-43 h) at isothermal temperature of 50 °C. The diffraction patterns of Portland cement demonstrate a large amount of crystalline component which is determined by the contribution of H6O30Si6Ca18 and O16Si4Ca8 clinker phases to the intensity. We consider the presence of hydrogen atoms in crystal lattices of H6O30Si6Ca18 and O16Si4Ca8 phases. It is shown alite phase is most of all involved in the hydration process the amount of which significantly reduces during this period, and the dissolution of O16Si4Ca8 phase occurs less intensively due to the higher atomic-binding energy in the crystal lattice. The energy-intensity of dissolution of O16Si4Ca8 surface atoms is higher than that of H6O30Si6Ca18 atoms in the crystal lattice. A comprehensive study of the quantitative phase composition of Portland cement shows that the bulk structures of clinker phases are not involved in the process of hydration. Experiments demonstrate that the crystal lattices of these phases are highly stable, and their binding energy tends to increase with the rise in curing time. The atomic-binding energy in crystal lattices of alite and larnite ranges within (187.3...187.616) and (496.764...97.016) eV, respectively. A high level of the atomic-binding energy indicates to the dissolution occurring at the interface between the solid and liquid phases. A certain atomic re-arrangement inside the crystal lattices can be accepted within the interval of stability as well as a variation of the number of atoms in unit cells. [ABSTRACT FROM AUTHOR]

Nanocomposite 1D CuI crystal@SWNT was obtained by the growth of CuI nanocrystals inside single walled carbon nanotubes (SWNTs) using the capillary technique. High resolution transmission electron microscopy (HRTEM) investigation of the atomic structure of 1D CuI crystals revealed two types of 1D CuI crystals: with growth direction <001> and <110> relative to the bulk hexagonal CuI stucture. EM images were recorded and atomic models of the structure were proposed. According to the proposed models and image simulations, the main contrast in the 1D crystal images arises from the iodine atoms. In this paper the 1D CuI crystal@SWNT nanocomposite behavior determined mainly by the influence of the electron beam was investigated and it is shown that the 1D CuI nanocrystals can oscillate and rotate inside the nanotube channel under a 100kV electron beam. The oscillations occur within an exposure time of 25 s. With longer exposure time of ∼90 s, the 1D crystal gradually decreases in length, sometimes moving inside the SWNT, CuI begins to evaporate and extruded, probably through defects in the tube wall. Outside the tube iodine is gradually lost but copper atoms are condensed into faceted clusters which grow subsequently into 3D Cu nanocrystals with fcc lattice. [ABSTRACT FROM AUTHOR]

The paper describes important improvements in the construction and operation of a miniature mass- and energy-analyzer of the Thomson type, which was developed especially for measurements of ions inside vacuum experimental chambers. The described analyzer constitutes a modified and improved version of the prototype miniature mass-spectrometer, which was designed several years ago. The paper describes experimental tests of the modified analyzer, which were carried out in the RPI-IBIS facility equipped with a multi-rod plasma injector. Results of the detailed measurements of energy distributions of protons and deuterons (from deuterium discharges) within the energy range from about 20 keV to about 300 keV are also presented. [ABSTRACT FROM AUTHOR]

The paper reports on experimental developments for studies of decays of proton radioactive nuclei on the Argonne Fragment Mass Analyzer. The results illustrate that there is a clear proton decay rate sensitivity to the unpaired neutron orbital in highly deformed odd-odd nuclei consistent with the Influential Spectator Model of Ferreira and Maglione. No such sensitivity is observed for the proton decay rates of spherical odd-odd nuclei studied here. The first ever study of proton decay from a nucleus, 135Tb, produced via 1p6n fusion evaporation is also reported. © 2004 American Institute of Physics [ABSTRACT FROM AUTHOR]

Ionizing radiation is utilized in many industrial, medical and research applications. The term ionizing radiation implies that the interaction of the radiation with the object of interest occurs at the atomic level, through the removal of electrons from atoms and molecules. In trying to understand, enhance and develop technologies that utilize ionizing radiation, atomic data and' tools to utilize these data sets are essential. In this paper some current applications of ionizing radiation are discussed. The computational tools applied to these situations are outlined. Currently available data sets are reviewed. Data needs are discussed as are some of the efforts underway at the National Institute of Standards and Technology (NIST) to enhance both data and tools. [ABSTRACT FROM AUTHOR]

QED corrections in few-electron atomic systems can be extracted from measured transition frequencies if the lower order nonrelativistic energies and relativistic corrections can be calculated to sufficient accuracy. This paper will particularly emphasize the region of low nuclear charge Z, where essentially exact results are available for the nonrelativistic energy and lowest-order relativistic corrections of order α[sup 2]Z[sup 4]. Helium and He-like ions have been particularly well studied. Spin-dependent corrections of O(α[sup 4]) and O(α[sup 5] ln α) have been calculated, and work on terms of pure O(α[sup 5]) is in progress. A comparison with experiment at the 1 kHz level of accuracy for the fine structure splittings of the 1s2p[sup 3]P[sub J] states will yield a significant new measurement of the fine structure constant α. Other comparisons with experiment are presented for the QED shifts in total energies. Recently, important progress has been achieved for lithium and Li-like ions, including the use of isotope shifts to measure the nuclear charge radius of the exotic neutron-rich “halo” nucleus [sup 11]Li. © 2000 American Institute of Physics. [ABSTRACT FROM AUTHOR]

This paper reviews advances in the area of electron scattering from laser excited atoms since the XX International Conference on the Physics of Electronic and Atomic Collisions (ICPEAC) in Vienna. It discusses superelastic scattering of electrons from potassium and from rubidium. The excitation of higher lying states from excited P states in both sodium and barium is discussed. Elastic scattering from the (...6s 6p)[sup 1]P state and (...6s 5d)[sup 1,3]D states of barium is discussed as are experiments that observe elastic scattering from the 3[sup 2]P state in sodium. © 2000 American Institute of Physics. [ABSTRACT FROM AUTHOR]

The work presented in this paper gathers three main technical developments aiming at 1) optimizing nuclide production by the mean of solid targets 2) automatically transferring coin targets from vault to hotcell without human intervention 3) processing target dilution and purification in hotcell automatically. This system has been installed on a ACSI TR24 cyclotron in Strasbourg France. [ABSTRACT FROM AUTHOR]

In this paper, the ultrafast dissociation following Cl 2p core–shell excitation into the 10a1* antibonding orbital in CH2Cl2 and CD2Cl2 molecules is studied. It is observed the presence of atomic Auger lines associated to the decay of dissociated Cl* atoms. The choice of CH2Cl2 and CD2Cl2 molecules to study the competition between the atomic and molecular Auger decays, allow us to probe nuclear dynamics and electron relaxation occurring on a comparable time scale, keeping other parameters identical. [ABSTRACT FROM AUTHOR]

The permanent electric dipole moment (EDM) of the elementary particle has the sensitivity to the CP violation in the theories beyond the standard model (SM). The search for the EDM constitutes the stringent test to discriminate between the SM and beyond it. We plan to perform the electron EDM search by using the laser cooled francium (Fr) atom which has the largest enhancement factor of the electron EDM in the alkali atoms. In this paper, the present status of the laser cooled Fr factory that is being constructed at Cyclotron and Radioisotope Center (CYRIC), Tohoku University are reported. [ABSTRACT FROM AUTHOR]

A promising proposal by B. Kane for a scalable silicon quantum computer requires the placement of 31P atoms 20 nm apart and 10 nm below the surface in pure 28Si to 1 nm precision. This paper presents progress on a scheme for laser cooling and trapping single 31Si atoms in a magneto-optical trap (MOT), resonantly ionizing that one atom near threshold, and softly depositing the single 31Si+ ion in Si to nm precision at ∼100 eV. A few hours after deposition, 31Si beta decays to 31P+. The hyperfine structure and isotope shifts of the 221.7 nm cooling transition for the stable isotopes of Si have been measured with precision for the first time. Sufficient power for the MOT at this wavelength has also been demonstrated. New autoionizing states near threshold have been found and ionization cross sections determined. The velocity distributions of laser ablated Si atoms have been measured, and unexpected results have been found. Construction of the MOT and design of the ion optics are underway. [ABSTRACT FROM AUTHOR]

In this paper, the absorption coefficient and emissivity of non-equilibrium atomic hydrogen plasma have been calculated in the case of a steady state shock wave. For this purpose, the atomic level population profiles along the shock wave have been calculated using a collisional-radiative model coupled with the electron Boltzmann equation. The spectral coefficients are in turn the input for solving a one-dimensional radiative transfer equation, which allows to calculate the radiation intensity and radiative flux in the plasma slab. [ABSTRACT FROM AUTHOR]

An accurate investigation of the behavior of electronically excited states of atoms and molecules in the post shock relaxation zone of a trajectory point of the FIRE II flight experiment is carried out by means of a one-dimensional flow solver coupled to a collisional-radiative model. In the rapidly ionizing regime behind a strong shock wave, the high lying bound electronic states of atoms are depleted. This leads the electronic energy level populations of atoms to depart from Boltzmann distributions which strongly affects the non-equilibrium ionization process as well as the radiative signature. The importance of correct modeling of the interaction of radiation and matter is discussed showing a strong influence on the physico-chemical properties of the gas. The paper clearly puts forward the shortcomings of the simplified approach often used in literature which strongly relies on the escape factors to characterize the optical thickness of the gas. [ABSTRACT FROM AUTHOR]

The Virtual Atomic and Molecular Data Centre (VAMDC, http://www.vamdc.eu/) is a European-Union-funded collaboration between groups involved in the generation, evaluation, and use of atomic and molecular data. VAMDC aims to build a reliable, open, flexible and interoperable e-science interface to existing atomic and molecular data. The project will cover establishing the core consortium, the development and deployment of the infrastructure and the development of interfaces to the existing atomic and molecular databases. This paper describes the organisation of the project and the achievements during its first year. [ABSTRACT FROM AUTHOR]

The paper is an update on the Atomic Data and Analysis Structure, ADAS, since ICAM-DATA06 and a forward look to its evolution in the next five years. ADAS is an international project supporting principally magnetic confinement fusion research. It has participant laboratories throughout the world, including ITER and all its partner countries. In parallel with ADAS, the ADAS-EU Project provides enhanced support for fusion research at Associated Laboratories and Universities in Europe and ITER. OPEN-ADAS, sponsored jointly by the ADAS Project and IAEA, is the mechanism for open access to principal ADAS atomic data classes and facilitating software for their use. EXTENDED-ADAS comprises a variety of special, integrated application software, beyond the purely atomic bounds of ADAS, tuned closely to specific diagnostic analyses and plasma models. The current scientific content and scope of these various ADAS and ADAS related activities are briefly reviewed. These span a number of themes including heavy element spectroscopy and models, charge exchange spectroscopy, beam emission spectroscopy and special features which provide a broad baseline of atomic modelling and support. Emphasis will be placed on 'lifting the fundamental data baseline'-a principal ADAS task for the next few years. This will include discussion of ADAS and ADAS-EU coordinated and shared activities and some of the methods being exploited. [ABSTRACT FROM AUTHOR]

The introduction of rare earth atoms and molecules into lighting discharges led to great advances in efficacy of these lamps. Atoms such as Dy, Ho and Ce provide excellent radiation sources for lighting applications, with rich visible spectra, such that a suitable combination of these elements can provide high quality white light. Rare earth molecules have also proved important in enhancing the radiation spectrum from phosphors in fluorescent lamps. This paper reviews some of the current aspects of lighting research, particularly rare earth chemistry and radiation, and the associated fundamental atomic and molecular data. [ABSTRACT FROM AUTHOR]

In this paper, we studied a system of three atoms with a cavity field interacting stochastically under a random phase telegraph noise (RPTN). The Jaynes-Cummings-two level atom- model with the RPTN is considered. An analytic (exact) solution for the system is obtained and examined for three atoms entanglement properties. The fidelity of this subsystem is calculated to observe whether three atoms that are in a three-partite mixed state do not become genuinely three-partite entangled when RPTN is present. [ABSTRACT FROM AUTHOR]

Learning about radiation requires understanding the general structure of atoms, but many college physics students do not have such understandings. In our efforts to develop inquiry based materials on radiation, we have accumulated additional evidence showing that certain students do indeed have substantial difficulties understanding the basic structure and properties of atoms, and that these difficulties impair their understandings of the simplest radiation processes-emission and ionization. This paper reports on our investigations of student difficulties in understanding basic properties of atoms and ionization and radioactivity. We also describe results from a class using a new pedagogical simulator-the Atom Builder-and provide evidence for marked improvement in student understanding. [ABSTRACT FROM AUTHOR]

This chapter is an attempt to attain a new and profound model of the nature’s structure using a vortex-ring-fractal theory (VRFT). Scientists have been trying to explain some phenomena in Nature that have not been explained so far. The aim of this paper is the vortex-ring-fractal modeling of elements in the Mendeleev’s periodic table, which is not in contradiction to the known laws of nature. We would like to find some acceptable structure model of the hydrogen as a vortex-fractal-coil structure of the proton and a vortex-fractal-ring structure of the electron. It is known that planetary model of the hydrogen atom is not right, the classical quantum model is too abstract. Our imagination is that the hydrogen is a levitation system of the proton and the electron. Structures of helium, oxygen, and carbon atoms and a hydrogen molecule are presented too. [ABSTRACT FROM AUTHOR]

New experimental information has been obtained recently on shape coexistence features in 43S27 and 44S28. These data confirm that Sulfur isotopes, in the vicinity of N = 28, belong to a region of spherical-deformed shape transition between 48Ca and 42Si. In this paper, the onset of collectivity and its impact on the structure of N∼28 isotones is discussed. [ABSTRACT FROM AUTHOR]

It has been previously shown that one can use the method of Maximum (relative) Entropy (ME) (Caticha Giffin 2006) to reproduce a mean field Solution for a simple fluid (Tseng 2004). One could easily use the case of a simple ferromagnetic material as well. The drawback to the mean field approach is that one must assume that all atoms must all act the same. The problem becomes more tractable when the agents are only allowed to interact with their nearest neighbors and can be in only two possible states. The easiest case being an Ising model. The purpose of this paper is to illustrate the use of the ME method as an approximation tool. The paper illustrates a simple case to compare with the traditional mean field approach. Then we show two examples that lie outside of traditional methodologies. These cases explore a ferromagnetic material with defects. The main result is that regardless of the case, the ME method provides good approximations for each case which would not otherwise be possible or at least well justified. [ABSTRACT FROM AUTHOR]

In this paper we first focus on the methods developed to control the position and the velocity of atoms, taking advantage of the radiative forces exerted on atoms placed in a laser beam. Temperatures in the range of μK can be reached for dilute atomic clouds trapped under vacuum in a very small region of space. The application to fountain clocks based on cold cesium atoms is presented. We then describe the characterization and the main features of Bose-Einstein condensates, a new state of matter of purely quantum origin, which can be obtained by subsequent evaporative cooling. The methods in use for cooling molecules are considered, in particular the collision processes or the photoassociation of cold atoms. The possibility of changing interactions between ultracold particles is also explained and photoassociation is illustrated by the recent experiments of our group dealing with metastable helium atoms. [ABSTRACT FROM AUTHOR]

Nuclear isomers have served as important touchstones in the development of nuclear models. In addition, those metastable excited states whose lifetimes reach decades or longer present intriguing possibilities as high-energy-density media. Together, these aspects have motivated considerable research on whether some isomeric nuclides might allow an induced release of the stored energy upon demand. Targeted studies of nuclear structure aimed at this question are a rather recent development, providing a parallel approach to direct tests of induced depletion on isomeric samples. This paper will discuss the relationship between these dual research tracks, as exemplified by experiments conducted on isomeric nuclei in 108Ag, 178Hf and 108Ta. [ABSTRACT FROM AUTHOR]

Molecular dipole polarizabilities and C6 dispersion energy coefficients can be calculated with an accuracy approaching that of the most reliable experimental determinations. Further molecular multipole properties, such as quadrupole and octopole polarizabilities and C8 dispersion energy coefficients, can also be calculated easily. However, for all but the smallest molecules, accurate computational modelling requires properties of the individual atoms or functional groups of the molecules, such as atomic charge densities, polarizabilities and dispersion energy coefficients. Such properties are not readily available from experiment or theory. This paper begins with a review of recent work on calculating atomic polarizabilities. A method which is beginning to show positive results is based on localising the derivatives of the atomic multipoles. A number of methods for calculating atomic multipoles are available, and some new results are presented for atomic multipoles and polarizabilities, based on an iterative partitioning scheme. Finally, the general principles behind more accurate, correlated calculations of atomic polarizabilities and dispersion energy coefficients are discussed. [ABSTRACT FROM AUTHOR]

We use recently calculated next-to-next-to-leading order (NNLO) anomalous dimension coefficients for the moments of the F2 structure function in eN scattering, together with the corresponding two-loop Wilson coefficients, to obtain improved QCD predictions for non-singlet structure function. The Jacobi polynomial method is used to parameterize parton distribution up to NNLO. Target mass corrections is also consider in our calculations. [ABSTRACT FROM AUTHOR]

We present in this paper a review of our work on the impact of long-range interactions on the static and dynamic behaviors of magneto-optical traps (MOT) for neutral atoms. In such systems, all forces (confinement and interaction) are mediated by light. The most obvious signature of long-range interactions is the dependence of the MOT size with number N of trapped atoms. We study in detail the scaling laws for the MOT size versus N, in a range of large N>108. We then show that the competition between confinement and repulsive interaction can lead, for N large, to a new dynamical instability characterized by spontaneous, self-sustained oscillations of the MOT. This instability is investigated experimentally and theoretically, using both a simple analytical model and a more refined numerical one. [ABSTRACT FROM AUTHOR]

The manipulation of cold atoms with optical fields is a very promising technique for a variety of applications ranging from laser cooling and trapping to coherent atom transport and matter wave interferometry. Optical fields have also been proposed as interesting tools for quantum information processing with cold atoms. In this paper, we present a theoretical study of the dynamics of a cold 87Rb atomic cloud falling in the gravity field in the presence of two crossing dipole guides. The cloud is either deflected or split between the two branches of this guide. We explore the possibilities of optimization of this device and present preliminary results obtained in the case of zero-temperature dilute Bose-Einstein condensates. [ABSTRACT FROM AUTHOR]

“The International Virtual Observatory Alliance” promotes the “development of tools, protocols and collaborations necessary to realize the full scientific potential of astronomical databases in the coming decade”. In this paper, we describe the virtual observatory organisation at international, national and local levels focusing on organisational structures linked to our VO activities. Further we report our latest developments concerning access to Atomic and Molecular Linelists Databases within the Virtual Observatories, addressing the definition of standards through a proposed Data Model, an access protocol to linelists, and their implementation on customized spectroscopic data from the CDMS/JPL spectroscopic databases. We will present how these new standards allow interoperability between the CDMS/JPL and the BASECOL databases, and between these databases and both a numerical code (PDR code from Meudon) and a spectral analysis software (DALIA). © 2007 American Institute of Physics [ABSTRACT FROM AUTHOR]

The production of stable and radioactive residual nuclides by medium-energy protons and neutrons is of importance for many fields of basic and applied sciences ranging from astrophysics over space and environmental sciences, medicine, accelerator technology, space and aviation technology to accelerator driven transmutation of nuclear waste and energy amplification. In this paper, the up-to-now achievements, new developments and still open questions in the understanding of nuclide production at medium energies are discussed emphasizing the production of cosmogenic nuclides in extraterrestrial matter and pointing out some references to recent investigations related to transmutation studies. © 2007 American Institute of Physics [ABSTRACT FROM AUTHOR]

Over the last several years, the boson-Hubbard Hamiltonian has been widely used as an effective model of the physics of ultra-cold optically trapped atoms. In this paper we will review its equilibrium properties, in one dimension, both in the absence and in the presence of an external potential. Then we will describe some new results for the visibility V of the interference pattern obtained after the free expansion of a gas. We will show that the evolution of V exhibits kinks with increasing interaction strength U/t, replicating phenomena seen experimentally. The behavior of the density profiles ni correlates well with the features in V. These profiles reveal an unexpected ‘freezing’ — a range of interaction strengths in which they remain unchanged. Finally, we show that V exhibits an increase with U/t signaling when a central ni = 2 Mott region melts and coherence develops between two superfluid regions with local densities 1 < ni < 2. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

We discuss in this paper ground-state and nonequilibrium properties of ultracold atoms in optical lattices in the strongly correlated limit. We review fermionic Mott-insulators studied on the basis of quantum Monte Carlo simulations, where local quantum criticality is displayed in one dimension. We continue with exact results for hard-core bosons in one dimension, showing their universal properties in equilibrium, and their nonequilibrium dynamics. Here we show that starting from a Fock state, a quasi-condensate emerges at finite momentum during free expansion. On the other hand, the free evolution of an initially confined quasi-condensate of hard-core bosons leads to a bosonic gas with a Fermi edge, and hence a fermionization that can only be obtained out of equilibrium. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

There is currently no reliable theory for calculating the fully differential cross section (FDCS) for low energy electron-impact ionization of molecules. All of the existing experimental FDCS data represent averages over all molecular orientations and this can be an important theoretical complication for calculations that are computer intensive. We have found that using an averaged molecular orbital is an accurate approximation for ionization of ground states. In this paper, we will describe the approximation, discuss its expected range of validity and show some FDCS results using the approximation for ionization of H2 and N2. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

The theory of electron impact ionization of one- and two-electron atoms has advanced significantly in the past two years. This paper will summarize the progress that the members of our research center have contributed to. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

This paper reports on our progress in attempting to realise an apparatus for studying atomic and molecular clusters. Specifically, we describe our design and present some preliminary results for a new triple coincidence electron momentum spectrometer. This apparatus is an (e,2e + ion) configuration where the two electrons from an electron impact ionisation event and the residual ion are detected in coincidence in order to probe the intermolecular bonding in van der Waals clusters. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]