Day 1 :
Keynote Forum
Peter Winkler
University of Nevada, USA
Keynote: Siegert’s curse and redemption: Taming and domesticating divergent wave functions
Time : 09:00-09:40
Biography:
Peter Winkler has obtained his Dr. rer.nat. degree (PhD) in Nuclear Physics and later his Dr. rer. nat. habil. degree from the University Erlangen in Germany. In 1979, he joined the Physics Department of the University of Nevada at Reno for teaching and research. His research interests focused on atomic many-body theory. He obtained tenure in 1985 and became Emeritus Professor in 2013 after having directed 12 students in their dissertation research. He is a Fellow of the American Physical Society.
Abstract:
Metastable states of quantum systems can be evaluated as complex-valued eigen solutions of the time-independent Schrődinger equation if complex boundary conditions are applied. Such resonance boundary conditions have been formulated in the early days of quantum mechanics but, initially few calculations have been performed utilizing this concept because the corresponding wave functions diverge asymptotically. Subsequent advances in the computation of energies and widths of metastable states will be discussed when Siegert boundary conditions are applied to achieve the necessary analytic continuation onto the complex energy plane as well as schemes to sidestep the divergences altogether. Examples including potential resonances and multiply excited electronic states of atoms and ions illustrate the wide applicability of this approach.
Keynote Forum
Xueqiao Xu
Lawrence Livermore National Laboratory, USA
Keynote: Modeling tokamak boundary plasma turbulence and its role in setting divertor heat flux widths
Time : 09:40-10:20
Biography:
Xueqiao Xu has his expertise in Plasma Physics and Controlled Nuclear Fusion. He has completed his PhD in 1990 from the University of Texas at Austin. He is a Principal Physicist at Lawrence Livermore National Laboratory and Guest Professor of Peking University.
Abstract:
The success of fusion experiments in ITER (International Thermonuclear Experimental Reactor) will require demonstrated
reliability in the plasma facing components (PFCs) to sustain the required pulse lengths. Understanding the physics of the scrape-off layer (SOL) width outside the magnetic separatrix is a crucial problem that must be solved in order to design a successful fusion reactor, as pointed out by the 2015 US Fusion Energy Sciences community workshops on Plasma-Material Interaction (PMI) and transients. The dominant view is that the Goldston “heuristic drift” model determines the peak heat flux. This model relies on magnetic drifts for ions and anomalous transport for electrons, but the anomalous transport mechanisms are not well understood and may depend on which edge transport regime the tokamak is operated in. In this work, massively parallel BOUT++ simulations are used to investigate the nature of SOL transport in multiple international tokamaks, such as C-Mod, DIII-D and EAST. Nonlinear simulations find saturated modes localized at the outer mid-plane that are similar to the quasi-coherent modes; characteristics such as frequency, wavenumber, phase and fluctuation amplitudes are compared with probe and Phase Contrast Imaging measurements on the C-Mod enhanced D H-mode discharges. The heat flux transported to divert or displays a width that is within a factor of 2 of the profile measured by IR camera and probe measurements. The parallel electron heat fluxes onto the target from the BOUT++ simulations of C-Mod, DIII-D and EAST follow the experimental heat flux width scaling of the inverse dependence on the poloidal magnetic field with an outlier. This shows that blob-like turbulence is likely to play an important role in present devices, particularly for electrons. Further turbulence statistics analysis shows that the blobs are generated near the pedestal peak gradient region inside the magnetic separatrix and contribute to the transport of the particle and heat in the SOL region.
Keynote Forum
Xiaodong Li
National University of Defense Technology, China
Keynote: What does an atomic nucleus look like?
Time : 10:20-11:00
Biography:
Xiaodong Li is a PhD holder from Université de Montréal (1993, crystal structure of mesophase molecules); MS from Nankai University (1981, functional polymers), BS from Tianjin University (1977). He is a Senior Professor in NUDT (National University of Defense Technology) researching and teaching in the fields of Polymer Chemistry and Physics, Material Chemistry, Ceramic Fibers And Composites, Material Engineering, Environmental Chemistry, Crystal Chemistry, Structure Chemistry and Nuclear Chemistry and Structure.
Abstract:
The more and more knowledge about molecular structure builds the footstone of modern chemistry. That arouses curiosity about the structure of the inner core of atoms. However, the nucleus is too small and is embedded by very thick electron “cloud” in normal state. What does a nucleus look like? Is it possible to “guess” it in a way as molecules? A new nuclear model of “ring plus extra nucleon” is proposed. The proton (P) and neutron (N) bind alternatively to form a right-angle folding ring. Based on it, extra nucleon binds in a similar way. Hereby, the shapes of some light nuclides were figured out, which are mostly not spheres, but with a generally linear relationship between the size and mass. The most excitement of this model is that, in even Z rings, the gravity centers of P and N are superimposed, while in odd Z rings, they must be eccentric. The eccentricity leads a lower EB/A. The extra nucleon(s) shift the eccentricity and the binding energy. This is exactly consistent with the normal even/odd zigzag feature found in EB/A and other properties in various cases. The model is also supported
by many basic evidence, including the nuclear stability and isotope limitation (see the attached figure), the spin similarity of “mirror” nuclides, the neutron halo of extremely neutron-rich nuclides and so on. From the nuclear structure, one may also explain the decay modes of unstable nuclide and furthermore, find some structural correlation with decayed daughter isotope. Since a huge task of computation is necessary to build the structure of large nuclide, where many “isomers” will be possible, a technique such as “nuclear mechanics”, which considers the weak interaction between all non-binding nucleons, is needed. It will be interesting that the combination of this model with quantum theory to obtain some new and more quantitative results. A correct nuclear structure may be useful to establish a more reasonable potential function in quantum computation.
- Atomic Physics | Atomic Spectroscopy | Nanotechnology
Location: Paramount Room
Chair
Alexander V Chaplik
Rzhanov Institute of Semiconductor Physics, Russia
Co-Chair
Manuel Bautista
Western Michigan University, USA
Session Introduction
Alexander V Chaplik
Rzhanov Institute of Semiconductor Physics, Russia
Title: Effect of the electron-electron interaction on the Raman scattering in quantum rings
Time : 11:20-11:45
Biography:
Alexander V Chaplik is graduated from the Saratov State University, PhD in the Institute for Radioelectronics Siberian Branch, Ac. of Sci. of the USSR. Since 1964, he has been a Minor Research Worker, Senior Research Worker and Head of laboratory at the Institute of Semiconductor Physics.
Abstract:
We investigate influence of the Coulomb interaction in the initial, final and intermediate states on the inelastic resonant light scattering by electrons confined to a quantum ring. The external magnetic field is supposed to be normal to the ring plane. Two examples are considered: The ring contains one (case a) or two (case b) electrons in the initial and final states. In accord with the typical experimental situation the incident light frequency is close to the energy gap of semiconductor and, moreover we suppose the spectral width of the exciting light to be sufficiently small so that one can tune into resonance with one of the discrete levels of the system in the intermediate (virtual) state. The latter is trion in the case A and trion plus remote electron in the case B. The amplitudes of the peaks of the scattered light intensity periodically depend on the magnetic flux piercing the ring with the period equal to the flux quantum. Accounting for the interparticle interaction in the intermediate state of the Raman process results in qualitative changes in the scattering cross-section when compared with the often used approximation that ignores that interaction. For example, the crosssections ratio for parallel and perpendicular polarizations of the incident and scattered light changes drastically depending on the spin of intermediate state. The latter can be purposely chosen by tuning the incident frequency because the Coulomb interaction splits in energy the states with different total spin. We analyzed all possible situations with different initial, intermediate and final total spin and found universal relations for intensities of scattered lines of different polarizations.
Manuel Bautista
Western Michigan University, USA
Title: An atomistic view of the universe
Time : 11:45-12:10
Biography:
Manuel Bautista is Associate Professor Astrophysics in the Department of Physics at Western Michigan University. He does theoretical research in atomic processes and atomic data for modeling of spectra from astronomical sources. His research is applicable to the study of many astronomical objects, such as stellar atmospheres and interiors, planetary atmospheres, supernovae and active galactic nuclei. He also models astronomical photoionized plasmas. He employs various computational tools, including massively parallel computers, to calculate properties of atoms and ions and to model the interactions between ions, light and particles in astronomical plasmas.
Abstract:
Astronomy, arguably the oldest of all physical sciences, has been the source of much our current understanding of the fundamentals processes that shape the physical world. Thus, it was through astronomical observations that atoms were recognized and their nature was understood. Since then, astronomy and atomic physics have progressed jointly and interdependently. In this talk, I review such progress in astronomy and atomic physics up to the present. I show that atomic physics for astrophysics is today as vibrant and important as ever. Then, I describe some of the work we carry out at Western Michigan University. Finally, I discuss some pressing
questions for the future, whose answers will require major theoretical and experimental advances.
Xiaodong Li
National University of Defense Technology, China
Title: To understand atomic nucleus from a new nuclear structure model
Time : 12:10-12:35
Biography:
Xiaodong Li is a PhD holder from Universite de Montreal and MS from Nankai University. He is teaching in NUDT as a Professor with the research fields of Polymer Chemistry, Material Chemistry and Physics. He has published more than 100 papers in reputed journals.
Abstract:
To explain some very basic facts of atomic nucleus, such as the stability of isotopes, the even-odd variation in many properties and so on, a nuclear structure model of ring plus extra nucleon is proposed. For nuclei larger than 4He inclusive, protons (P’s) and neutrons (N’s) are basically bound alternatively to form 2ZZ E ring. The ring folds with a bond angle of 90Ëš for every 3 continuous nucleons to make the nucleons packed densely. The ring must be identical when all the P and N interchange (negative symmetry). Extra N(’s) can bind to ring-P with the same manner. When 2 or more ring-P’s are geometrically available, the nuclide with extra N tends to be stable. Extra P can bind with ring-N in a similar way when the ratio of N/P <1 although the binding is much weaker. Even-Z rings always have superimposed gravity centers of P and N; while for odd-Z rings, both centers of P and N must be eccentric. The eccentricity results in a depression of EB and therefore specific zigzag features of EB/A. This can be well explained by the shift of eccentricity by extra nucleons. Symmetrical center may present in even-Z rings and normal even-even nuclei. While for odd-Z ring, only antisymmetric center is possible. Based on this model, a pair of mirror nuclei, PX+nNX and PXNX+n, should be equivalent in packing structure just like black-white photo and the negative film. Therefore, an identical spin and parity was confirmed for hundreds of pairs. In addition, the EB/A difference of all the mirror nuclei pair is very nearly a constant of 0.184n MeV. Many other facts can also be easily understood from this model, such as the nuclear stabilities of isotopes in elements from He to Ne; the stability sequence of 9Be, 10Be, 7Be and 8Be; the neutron halo in neutron-rich nuclides, the general rule for most stable isotopes: Odd-Z elements are odd A, even-Z elements are even A; and the highest cohesive energy of Li, Be, B atoms in their own elementary group and so on.
Feng Xie
Tsinghua University, China
Title: Recent research progress about the source term study on irradiated graphite spheres of HTR-10
Time : 12:35-13:00
Biography:
Feng Xie is working in Institute of Nuclear and New Energy Technology of Tsinghua University, Beijing, China. His research interests include source term analysis, the behavior of fission products and radioactive graphite dust, atomic molecular physics, and laser spectroscopy. Now, he is In Charge of the design and implementation of the radioactive graphite dust measurement system of the HTR-10, and process and effluents radiation monitoring system of the HTR-PM in China. He has received his Bachelor’s degree and PhD in 2003 and 2008 from the Department of Physics in Tsinghua University, respectively. In 2011, he assumed his current position in INET of Tsinghua University.
Abstract:
The very high temperature gas cooled reactor system (VHTR), as a development of high temperature gas-cooled reactors (HTGRs), has been identified as a candidate of the generation IV systems for the production of process heat, electricity and hydrogen. For the pebble bed high temperature gas cooled reactor, the performance of the fuel spheres in the core plays a crucial role with regard to nuclear safety. The nuclides produced in the core are the original source of radioactive substances into primary coolant and auxiliary
systems in a nuclear power plant. Thus, the determination of the source term in the reactor core can supply important information to understand the behavior of fission and activation products and provide reliable foundation to evaluate the radiation level of the nuclear facility. With previous developed experimental methods which include the preparation and measurement process for the graphite sample, four irradiated graphite spheres from the reactor core of the 10 MW high temperature gas-cooled reactor (HTR-10) have been investigated experimentally. The total β counting rate, the β spectra and the γ spectra for each graphite sample of irradiated graphite spheres were recorded with a total α/β counting measuring apparatus, a liquid scintillation counter and a highpurity germanium detector connected to a multichannel analyzer, respectively. The types of key nuclides in the irradiated graphite sphere of HTR-10 were determined, which were H-3, C-14, Co-60, Cs-137, Eu-152 and Eu-154. The distributions for each nuclide in four irradiated graphite spheres were compared. The generation mechanisms of H-3, C-14, Co-60, Cs-137, Eu-152 and Eu-154 in the irradiated graphite sphere of HTR-10 were discussed and analyzed. A sensitivity analysis was performed to explain the effect of the content of impurities and fraction of natural uranium contamination on the specific activity of key nuclides in the graphite spheres. Current study on irradiated graphite spheres of HTR-10 can provide valuable information for the source term analysis, waste minimization and radiation protection of high temperature gas-cooled reactors (HTGRs).
Zengyong Chu
National University of Defense Technology, China
Title: Mechanical self-assembly of highly-folded graphene oxides for ultralarge deforming actuators
Time : 14:10-14:35
Biography:
Zengyong Chu has his expertise in Molecular Physics and Chemistry. He has completed his PhD from National University of Defense Technology. He is Full Professor and Director of a research team focusing on Molecular Physics and Chemistry at National University of Defense Technology.
Abstract:
The fabrication of micro-/nano-patterns is of great significance to material science and technology, with numerous potential applications in microfluidics and microimprinting, wetting and adhesion, surface-enhanced Raman scattering (SERS), flexible electronics, mechanical property measurements, and cell culture biointerfaces. Gyrification in the human brain is driven by the compressive stress induced by the tangential expansion of the cortical layer, while similar topographies can also be induced by the tangential shrinkage of the spherical substrate. Herein we introduce a simple three-dimensional (3D) shrinking method to generate the cortex-like patterns using two-dimensional (2D) graphene oxide (GO) as the building blocks. By rotation-dip-coating a GO film on an air-charged latex balloon and then releasing the air slowly, a highly-folded hydrophobic GO surface can be induced. Wrinklingto-folding transition was observed and the folding state can be easily regulated by varying the pre-strain of the substrate and the thickness of the GO film. Driven by the residue stresses stored in the system, sheet-to-tube actuating occurs rapidly once the bilayer system is cut into slices. In response to some organic solvents, however, the square bilayer actuator exhibits excellent reversible, bidirectional, large-deformational curling properties on wetting and drying. An ultralarge curvature of 2.75 mm-1 was observed within 18 s from the original negative bending to the final positive bending in response to tetrahydrofuran (THF). In addition to a mechanical hand, a swimming worm, a smart package, a bionic mimosa and two bionic flowers, a crude oil collector has been designed and demonstrated, aided by the superhydrophobic and superoleophilic modified GO surface and the solvent-responsive bilayer system. So the method demonstrated here is not only able to fabricate highly folded cortex-like patterns with superhydrophobic and superoleophilic properties, but also to fabricate interesting reversible bilayer actuators with ultralarge deformations for versatile applications.
Igor M Savukov
Los Alamos National Laboratory, USA
Title: Calculations with parametric CI-MBPT method of properties of complex atoms
Time : 14:35-15:00
Biography:
Igor M Savukov has completed his PhD in 2002 at the University of Notre Dame, IN USA, and in 2006 his postdoctoral studies at Princeton University. Currently, he is an R&D Scientist at Los Alamos National Laboratory. He has published 80 papers in reputed journals, h index 22, and has been working over 20 years in the field of atomic structure calculations especially in the field of relativistic many-body theory.
Abstract:
Many complex atoms, such as actinides, present difficulties for theory. The difficulties are manifold: 1) valence electrons interact strongly, requiring generation and eigen solution of a large matrix to treat the interaction accurately; 2) many valence electrons interact strongly with 86 core electrons, and these interactions have to be taken into account beyond the small-perturbation level; 3) relativistic effects are very important, affecting the order of closely spaced levels and many atomic properties. Currently there are no calculations demonstrating accurate energy levels and other properties of the neutral U atom or other actinides. The only method that has been used throughout the world so far is a multi-configuration Hartree-Fock (MCHF) approach, developed by Cowan at LANL more than 30 years ago, and which contains various fitting parameters. Configuration-interaction many-body perturbation theory (CI-MBPT) is a promising method, since it demonstrated high accuracy in light multi-valence atoms. However, valence-core interactions in actinides are very strong to be treated in the second-order MBPT, used in the CI-MBPT method. One solution is the CI-All-order method, but it is quite time consuming and rather complex. An alternative solution is to introduce fitting parameters into CI-MBPT to account for valence -core, relativistic and omitted valence-valence interactions. Using this parametric CI -MBPT approach it is possible to match energy levels with the precision of about 100 inverse cm for atoms such as Th and U III. This resulted in simplification of matching theoretical and experimental levels, and quite accurate g-factors. Some preliminary calculations have also showed that the theory can predict oscillator strengths. Examples of Xe I, Y I, U I, Th I and other atom calculations will be given to demonstrate improved accuracy of the CI-MBPT approach. This is just first attempts showing great promise of the parametric CI-MBPT approach to actinide atoms.
Oudjertli Salah
Université of Badji Mokhtar, Algeria
Title: Structural, microstructural and thermal characterization of Fe- doped ZnO powder nanostructures prepared by mechanical alloying
Time : 15:00-15:25
Biography:
Oudjertli Salah is a Researcher in Department of Physics, University of Badji Mokhtar Annaba, Algeria. He has more than four articles and 15 international congress communications his research focuses on the structural, and microstructural, properties of ZnO prepared by mechanical alloying. He mainly worked in nanomaterials, modulization, materials science, amorphous alloys and magnetic properties. His current research includes simulation and characterisation of nanostructured materials, nanocomposites, and nanotubes prepared by several methods; CVD, spray pyrolysis, mechanical alloying and ion implantation.
Abstract:
ZnO powder nanoparticles mechanically alloyed were doped with iron to investigate their structural and microstructural properties using X-ray diffraction (XRD) and differential scanning calorimetry (DSC) for examined 1% Fe doped ZnO. The ZnO starting pure powder exhibited a hexagonal crystal structure with space group p63mc of ZnO, however with the introduction of 1% Fe in the ZnO milled powder, the hexagonal ZnO phase remained unchanged, whereas the microstructural parameters were subject
to significant variations due to the introduction of Fe atoms into the ZnO hexagonal matrix to replace oxygen ones. The size of crystallites and microstrains are found milling time dependent.
Arn Olds Ikkema
FAS Institute, Finland
Title: Atomic spectroscopy of Si bolidium narcosum at negative temperature
Time : 15:25-15:50
Biography:
Arn Olds Ikkema has his expertise in atomic spectroscopy at extreme temperatures. He completed his PhD from Swedish Institute of Neural Neutronics. He is Professor and Director of a research team focusing on Atomic Spectroscopy at Finland’s renowned FAS Institute.
Abstract:
As expected when temperatures approach zero, the atomic spectrum of hot gases become isomorphic to renormalizable grouptheoretic
pattern formation. However, with an inverted population induced by laser adsorption of monomolecular surface waves, emissions exceed absorptions until equilibrium values are adiabatic. Presenting on behalf of a local international consortium of independent researchers whose interests cannot be divulged due to Trumpian economic and chemotherapeutic controls, I will show how neural neutrons can ameliorate the set of equations which retrodict ecliptic holography of the recently characterized medial isotope of Si bolidium narcosum, promising to overturn diagnostic therapies of Eastern Africa.
- Poster Presentations
Location: Pre-Function Space
Chair
Alexander V Chaplik
Rzhanov Institute of Semiconductor Physics, Russia
Session Introduction
Nobuo Nishimiya
Tokyo Polytechnic University, Japan
Title: Zeeman spectra of Ti I in a facing target sputtering system
Biography:
Nobuo Nishimiya is working on spectroscopic research on molecules and atoms. He has completed his PhD from Tokyo Institute of Technology. He is Professor at Tokyo Polytechnic University.
Abstract:
Absorption spectroscopy is useful for plasma diagnostics. Several functional films were fabricated using a facing target sputtering (FTS) system. During the sputtering process using the FTS system, high-energy ionized particles are confined by a magnetic field. However, the absorption lines of a species are split into the Zeeman components. The Lande gJ factor is very important for determination of the nature of atoms in a magnetic field. The saturated absorption lines of neutral Ti were measured in the region of 9950–14380 cm-1 by using a Ti: sapphire ring laser. The FTS system was used to obtain the gaseous state of a neutral Ti atom in this experiment. The Zeeman splitting of 38 transitions of 46, 47, 48, 49, 50Ti species was observed. For 48Ti species, the difference between the gJ factors of the odd and even parity states was obtained from the Zeeman splitting under the condition that the electric field component of a linearly polarized laser beam was parallel to the magnetic field. The gJ factors of the odd parity states were determined for 28 energy levels belonging to 3d24s4p and 3d34p by using those of the even parity states reported by E Stachowska in 1997. The gJ factors of z5P1, 2, 3 levels were determined for the first time. gJ of y3F2, y3D2, z3P2, and z5S2 levels in the region of 25000–25600 cm-1 were refined. In addition, for the odd mass isotopes of 47, 49Ti of b3FJ -y3DJ-1, the intermediate field approximated by calculation of the Zeeman effects in the hyperfine structure was used.
Shinji Kobayashi
Tokyo Polytechnic University, Japan
Title: Isotope shift of Ti spectrum in a facing target sputtering system
Biography:
Shinji Kobayashi is doctoral student in Japan. He is majoring in the department of electronics and information Technology. He is researching about atomic or molecular spectroscopy.
Abstract:
Laser spectroscopy is one of the useful methods of plasma diagnostics. In order to measure the plasma density and temperature, parameters of the line profile of the spectrum need to be determined. In this study, we measured the absorption spectrum of Ti atom in a facing target sputtering (FTS) system by using a Ti: sapphire laser. It is difficult to determine the parameters of the line profile of the Ti spectrum, because Ti has five stable isotopes and hence the spectra are complicated. The saturated absorption spectrum in 3d24s2→3d24s4p, 3d34s→3d24s4p, and 3d34s→3d34p electronic transitions of neutral titanium in the FTS system were measured in the range from 695 to 1005 nm. The even mass isotope shifts of 46Ti and 50Ti for 48Ti have been measured. The accuracy of absolute frequency of the Ti spectra was 0.001 cm-1. The King plot analysis was performed for those transitions. The specific mass shift of Ti I is much larger than the field shift. The several energy levels belonging to 3d34p interact with those of 3d24s4p. The specific mass shift of 3d34p depends on the contribution from 3d24s4p. The relationship between the interaction and the specific mass shift is linear. The specific mass shift of the levels belonging to 3d24s4p and 3d34p can be semi-empirically determined.