Day 2 :
Keynote Forum
Donald J Kouri
University of Houston, USA
Keynote: Generalizing the harmonic oscillator and Fourier analysis: An infinite family of mutually unbiased bases
Time : 09:00-09:40
Biography:
Donald J Kouri has completed his PhD from University of Wisconsin in the year 1965. He carries research in the fundamental implications of the Heisenberg uncertainty principle and the resulting applications and also generalized coherent states, quantum theory of atomic and molecular collisions.
Abstract:
We consider canonical transformations from the standard coordinate, x, to new coordinates that either stretch or compress the real line. The guide to our choice of transformation comes from consideration of supersymmetric quantum mechanics and the fact that it shows that any 1-D ground state minimizes the Heisenberg uncertainty product of the new coordinate and conjugate momentum. Using the fact that the transformation is a point transformation, it is easy to obtain the conjugate classical momentum. These are quantized, resulting in Heisenberg-Weyl Lie algebra. In parallel to the connection of the harmonic oscillator eigenstates and the Fourier transform, we obtain a generalization of the Fourier transform kernel which is ideally suited to the harmonic analysis of chirps. In addition, the (improper) eigenstates of the new position and momentum operators, as well as their sum are shown to constitute a mutually unbiased set of basis states. The appearance of the Heisenberg-Weyl Lie algebra also leads to a generalized harmonic oscillator (GHO), whose eigenstates are also eigenstates of the generalized Fourier transform kernel. The ground states of these GHOs are simply generalizations of the Gaussian and share many important properties of the Gaussian. In particular, they are attractor solutions of a Fokker-Planck equation who’s laplacian is simply the kinetic energy operator of the GHO. The simplest form of these ground states is , where N is the normalization factor and the integer, n, ranges from zero on up. The generalized laplacian for the GHO is , . The potential of the GHO is . However, we show that one may also have polynomials (of a specific structure) as the argument of the exponential ground state. We will discuss various possible applications of our results.
Keynote Forum
Masayoshi Tanaka
Kobe Tokiwa University, Japan
Keynote: Research activity on experimental nuclear physics aided by atomic physics
Time : 09:40-10:20
Biography:
Masayoshi Tanaka did his PhD Physics and currently, is Professor of Clinical Technology and Physics and Collaborative Physicist at RCNP, Osaka University. He got the Prefectural Award of Hyogo for research and education in 2013. He organized the Int. Workshop, HELION97 on polarized 3He beams and gas targets and their application in 1997. He was a guest Researcher at University of Michigan in 2001, CEN (Centre d'études nucléaires de Grenoble in 1990, and at MPI (Max Planck Institut für Kern Physik), Heidelberg in 1982.
Abstract:
The last century was no doubt, an epoch-making century for physics. Guided by the new concept such as the quantum mechanics, and the special and general relativities, the territory of physics was broadened diversely from the elementary particles to the cosmos in size, from 10-6 to 10+8 K in temperature, and from inanimate to animate objects. In particular, the discovery of the atomic nucleus by E. Rutherford in 1911 and the quantum mechanical interpretation of hydrogen atom by N. Bohr in 1913 greatly contributed in opening a new window of physics. Even now, atomic and nuclear physics keep on evolving as heart and soul of the modern physics. Today, I am going to emphasize how deeply nuclear physics research I have committed for long time has been luckily helped by atomic physics in my talk. My first job as a nuclear physicist is to determine the magnetic sub-state populations of the product nucleus implanted in a metallic foil following the nuclear reaction. However, experimental results could not uniquely predict the magnetic sub-state populations. For breaking this difficulty, we must decide the sign of eqQ (electric quadrupolar interaction) of the product nucleus in the metal. This was done by combining the particle-γ angular correlation measurement of this nuclear reaction. Thus, new information on the nuclear wave function of the product nucleus was extracted successfully. We started, after that, developing the polarized 3He ion source for nuclear physics at an intermediate energy region. The device used an ECR (Electron Cyclotron Resonance) ionizer, and laser optical pumping. My experience at MPI, Heidelberg and CEN, Grenoble decisively helped in promoting our project. People from
either domestic (Osaka, Konan, and Niigata) or foreign institutes (Dubna, Madison, and Vancouver) joined us from time to time to contribute to atomic physics as well as nuclear physics. Meanwhile, we succeeded in experimentally proving the principle of electron pumping, which an extended concept of the optical is pumping, i.e., electrons can play a role of photons in the optical pumping. The latest 10 years have been spent on the development of the Hyperpolarized MRI (Magnetic Resonance Imaging) for medical diagnosis as presented in this conference.
Keynote Forum
Alain Ghizzo
University of Lorraine, France
Keynote: Non-particle vlasov codes: Key issues and impact on plasma turbulence modeling for thermonuclear fusion
Time : 10:20-11:00
Biography:
Alain Ghizzo has received his PhD degree in Plasma Physics in 1987. He is currently a Professor at the University of Lorraine at the Institue Jean Lamour (UMR 7198). He has been performing research in the field of computer experiments in plasma physics. His recent research includes laser-plasma interaction and gyrokinetic models for plasma core physics in tokamaks and astrophysics.
Abstract:
Often referred to as “the fourth state of matter”, plasmas comprise over 99% of the visible universe and are rich in complex nonlinear and collective phenomena. The quest for harnessing fusion energy is a major component of research in the field of plasma physics. Thus the development of fusion as a secure and reliable energy system that is environmentally and economically sustainable is a formidable scientific but also technological challenge today. Although the fundamental laws that determine the behaviour of plasmas, such as Maxwell's equations and those of classical statistical mechanics are well known, obtaining their solution under realistic conditions is a scientific problem of extraordinary complexity. The use of fundamental equations often retains the full nonlinear effects, and space charge and other collective effects can be included self-consistently by coupling charged particles to the field equations via the source terms. For collisionless plasmas, the kinetic model is based on the vlasov equation (supplemented by the Poisson or Maxwell equations). Its numerical integration is one of the key challenges of computational plasma physics. This keynote summarizes the concepts and the latest developments in collisionless semi- Lagrangian vlasov plasma simulations and their impact on phase space topology and on turbulence modeling. Recent advances in simulations of hot fusion plasmas are reviewed, with illustrative examples, chosen from associated research areas as relativistic laser-plasma interaction or micro turbulence in tokamak plasmas. These examples illustrate the challenges in modeling wave- particle interactions in fusion plasmas. High accuracy and resolution are required to correctly model such Landau-type resonances. The challenging nature of plasma physics in general and fusion research in particular leads to establish an inter-disciplinarily research that targets the development of capabilities that “bridge” various areas of plasma physics together with computer science and applied mathematics.
- Nuclear Physics | Nuclear Fission and Fusion | Nuclear Medicine Physics
Location: Paramount Room
Chair
Masayoshi Tanaka
Kobe Tokiwa University, Japan
Co-Chair
R A Radhi
University of Baghdad, Iraq
Session Introduction
Masayoshi Tanaka
Kobe Tokiwa University, Japan
Title: Progress in creation of hyperpolarized nuclei for highly sensitive MRI
Time : 11:20-11:45
Biography:
Masayoshi Tanaka is a Professor of Clinical Technology and Physics and Collaborative Physicist at RCNP, Osaka University. He got the Prefectural Award of Hyogo for research and education in 2013. He organized the int. workshop, HELION97 on polarized 3He beams and gas targets and their application in 1997. He was a Guest Researcher at University of Michigan in 2001, Centre d'études nucléaires de Grenoble in 1990, and at Max Planck Institut für Kern Physik, Heidelberg in 1982.
Abstract:
Though the MRI (Magnetic Resonance Imaging) is widely used as a tool for medical diagnoses, its usefulness is rather restricted because of less pronounced NMR (Nuclear Magnetic Resonance) signals due to the smallness of nuclear polarization created at room and body temperature. As a result, it becomes difficult to obtain the images for low-density organs like a lung in a short measuring time. To break this restriction, we started developing a hyperpolarized MRI, where nuclear polarization is generated artificially by sophisticated technologies in nuclear physics or atomic physics, with which we hope the NMR signals would be orders of magnitudes enhanced relative to the NMR systems used so far, thus enabling us to obtain images with high resolution. Currently, we are constructing a device for hyperpolarized 3He gas by means of the Brute Force method with a strong high magnetic field (~17T) and an extremely low temperature (<100mK) and a device for hyperpolarized 19F in PFC (PerFluoro Carbon) often used as an artificial blood by means of the PHIP (ParaHydrogen Induced Polarization) method. No doubt, the PHIP will be successful, the lung image with the very expensive hyperpolarized 3He may be replaced with the cheap PFC. Further, it will be shortly touched that the hyperpolarized 17O MRI may be a potential tool instead of the risky radioactive 15O PET (Positron Emission Tomography) widely used for diagnosis of the brain diseases such as apoplectic stroke. Finally, let me ask for your attention on possibility to detect cancer cells with the hyperpolarized 13C MRI by measuring the rapid change of the chemical shifts due to the metabolic reactions in the cancer cells.
R A Radhi
University of Baghdad, Iraq
Title: Calculation of quadrupole transition rates in cross sd-pf shell isotopes (Si, S and Ar)
Time : 11:45-12:10
Biography:
R A Radhi is a retired Professor of Physics, Department of Physics, College of Science, University of Baghdad, and Baghdad Iraq. He did his PhD from Michigan State University 1983, MSc from University of Baghdad 1974, BSc from University of Basrah 1972 field of interests: nuclear structure, electron scattering, electromagnetic transitions and moments, exotic and halo nuclei, computational physics, hydrodynamics supervision: 18 MSc and 24 PhD students.
Abstract:
Quadrupole transition rates and effective charges are calculated for even-even Si, S and Ar isotopes with N>20. Shell model calculations are performed with sd-shell model space for protons and sdpf shell-model space for neutrons. Excitation out of major shell space are taken into account through a microscopic theory which allows particle-hole excitation from the core and model space orbits to all higher orbits with excitation. Effective charges are obtained for each isotope with N<20 and average effective charges are extracted and used for each nucleus. The results show a systematic increase in the B (E2) values. Shell model calculation predicts the erosion of the N=28 magicity in the neutron rich 42Si. No clear indications about the erosion of the shell gap closure in 44S and 46Ar isotopes.
G M Laurent
Auburn University, USA
Title: Optical control of electron emission at the attosecond timescale
Time : 12:10-12:35
Biography:
G M Laurent is an expert in Atomic and Molecular Physics. He received his PhD in 2004 from the University of Caen (France). He was a Post-doctoral fellow at the University of Madrid in Spain. In 2009, he joined the Physics Department at Kansas State University as a Research Associate, where he started his research in the field of attosecond science. In 2013, he moved to MIT as a Research Scientist to pursue his research in attosecond science and femtosecond laser development. Finally, in fall 2015 he joined the Physics Department at Auburn University as an Associate Professor.
Abstract:
Coherent control of electron dynamics in matter is a growing research field in ultrafast science, which has been mainly driven over the last two decades by major advances in laser technology. Recently, the advent of extreme-ultraviolet (EUV) light pulses in the attosecond time scale (1as=10-18s) has opened up new avenues for experimentalists to manipulate the electronic dynamics with unprecedented precision. In this work, we demonstrate that an asymmetric electron emission from atomic targets can be generated and controlled by combining an attosecond pulse train (APT) composed of both odd and even harmonics and a weak IR field (1011W/cm2). Electron wave-packets are formed by ionizing argon gas with such APT in the presence of the IR field. Consequently, a mix of energydegenerate even (s,d) and odd (p,f) parity states is fed into the continuum by one- and two-photon transitions. These interfere, leading to an asymmetric electron emission along the polarization vector. At some appropriate time delay between the APT and IR fields, the even and odd angular continuum wave function resulting from one and two-photon transitions, respectively, add constructively on one side (up) of the polarization vector direction and destructively on the other side (down), thus creating a strong up-down asymmetry in the angular emission of the photoelectrons. The direction of the emission can be controlled by varying the time delay between the two pulses. In addition, we show that such asymmetric emission is also related to the properties of the APT. The temporal analysis of the modulated electron emission, based on an accurate description of the atomic physics of the photoionization process, then provides a way to measure the temporal profile of the attosecond pulse. We propose a retrieval procedure which allows for the unique determination of the spectral phase making up the pulses. The procedure had been demonstrated for the characterization of an attosecond pulse train composed of odd and even harmonics. We observe a large phase shift between consecutive harmonics. Our results contradicts the generally accepted physical picture that the combination of even and odd harmonics in the train necessarily creates a series of pulses which occur only once per IR cycle. This picture holds only if there is no phase shift between even and odd harmonics. Otherwise, the resulting APT has a more complex structure not resembling a single AP once per IR period.
Akihide Hidaka
Japan Atomic Energy Agency, Japan
Title: Radionuclides release behaviors unique to the Fukushima Daiichi nuclear power plants accident
Time : 13:35-14:00
Biography:
Akihide Hidaka has his expertise in severe accident phenomena and nuclear human resource development. He has completed his PhD from the Tohoku University, Japan. He is Senior Principal Researcher of Japan Atomic Energy Agency. He carried out a study about radionuclide release from fuel, transport and deposition of radionuclide aerosol in the reactor coolant system or the containment, atmospheric dispersion of radionuclides at the time of nuclear power plant accidents. At present, he is performing the source term study for the Fukushima Daiichi Nuclear Power Plant accident while engaging in the atomic energy personnel training for Japanese and Asian countries’engineers.
Abstract:
A lot of analyses on the source terms for the Fukushima Daiichi Nuclear Power Plants accident have been tried mainly using the two methods. One is the reverse estimation using the atmospheric dispersion code combined with the environmental monitoring data. The other is the analysis of thermo-hydraulics and radionuclides release/transport using the severe accident codes such as MELCOR. Although some significant differences were found in the results between them, there are few studies with these points of view so far. Therefore, the present study focused on this point and the following findings were obtained. 1) The 131I release could have occurred from a large amount of contaminated water in the basements of Units 2 and 3 reactor buildings because of the gas-liquid partition of 131I and steam generation from the accumulated water by decay heat. 2) The chemical form of certain fraction of released cesium could have been CsBO2, which was formed by reaction of CsOH with the boron originated from the B4C control rods. The chemical form could affect not only the cesium source term but also the environmental transport behavior. 3) The 129mTe release estimated by the reverse calculation showed that the release amount from Unit 2 may have been smaller than those from Unit 3. This can be explained by the recent TEPCO’s observation that the containment failure occurred at middle height of drywell at Unit 3 but at the bottom of suppression pool at Unit 2 where the radionuclide removal by the pool scrubbing is expected. The similar release behaviors could be also inferred for 131I and 137Cs. These findings have never been considered or predicted in most of the existing severe accident codes that have been developed based on the findings of the TMI-2 accident in which most of radionuclides remained in the intact containment.
Alain Ghizzo
University of Lorraine, France
Title: Kinetic waves induced by electron trapping in stimulated Raman scattering in laser-plasma interaction
Time : 14:00-14:25
Biography:
Alain Ghizzo has received his PhD degree in Plasma Physics in 1987. He is currently, working as a Professor at the University of Lorraine at the Institute Jean Lamour (UMR 7198). He has been performing research in the field of computer experiments in plasma physics. His recent research includes laser-plasma interaction and gyrokinetic models for plasma core physics in tokamaks and astrophysics.
Abstract:
The influence of low-frequency waves of kinetic nature induced by electron trapping in backward stimulated Raman scattering is investigated. The kinetic theory of periodic electron hole equilibrium or phase space vortices is a long-standing problem in plasma physics. Since the pioneering work of Bernstein, Greene and Kruskal in 1957 it is now well-known that such phase space holes are self-sustained and connected to electrostatic fields that are self-consistent with some manner of trapped particle velocity distribution function. Trident laser-plasma interaction experiments, that revealed that such electron trapping structures might conceivably be physically relevant, have led to renewed interest in the research of such trapping structures. These experiments were aimed at improving our knowledge of stimulated Raman scattering (SRS) from electron plasma waves (EPWs) from a single speckle of laser light and employed laser scattering as a key diagnosis (in particular in optical mixing experiment). An extremely surprising result was the presence of a second very weak scattering signal which was only a modest fraction (0.37) of the plasma frequency in addition to the expected EPW scattering signal. This unexpected signal was associated with what was termed Stimulated Electron Acoustic Scattering (SEAS), a novel scattering involving a so-called electron acoustic wave (EAW), whose nature is nonlinear and kinetic. In such experiments, Raman scattering enters in the so-called kinetic regime of the instability. To explore the physics of such generation and to make contact with a possible laboratory experiment, a semi-Lagrangian kinetic Vlasov-Maxwell code is used which allows very fine details of the particle-wave resonance. We address here the results of numerical experiments leading to the generation of self-sustained low frequency kinetic electrostatic electron nonlinear (KEEN) waves starting initial collision less Maxwellian plasma in an appropriate computer model for the one-dimensional system. Then we investigate the interaction of such created KEEN waves with the laser wave showing the possibility of interaction of such quasi-particles with electromagnetic wave.
Gregory Lapicki
East Carolina University, USA
Title: Applications of the proton induced x-ray emission (PIXE) technique for elemental analysis of materials
Time : 14:25-14:50
Biography:
Gregory Lapicki has completed his PhD from New York University and continued with Postdoctoral studies for two years in the Radiation and Solid Laboratory at NYU. He has worked at Centro Atómico, Bariloche, Argentina on the Fulbright Award. In 2013-2017, he has served on the International Advisory Committee for Particle Induced X-ray (PIXE) Conferences and presented opening invited talks at five of these conferences. In 2017, he was elected to the International Honorary Committee for PIXE. He has presented invited talks at the International Symposium on ion-atom collisions and the conference on applications of accelerators in research and industry, for which in 2017 he served as an atomic and molecular physics topic Editor. He has published almost 200 refereed papers in journals such Physical Review A, Nuclear and Instruments and Methods in Research B, Journal of Physics B, Journal of Physics and Chemistry Data, X-Ray Spectrometry, Radiation Physics and Chemistry, with a link to one of the most recent publications in atomic and nuclear data tables.
Abstract:
Background: The relevance of x-ray production cross sections (XRPCS) and the related ionization cross sections (ISC) in many research areas has been described at length and analyzed in detail. X-ray emission cross sections by ion impact are a relevant input in many areas such as particle induced x-ray emission (PIXE) strongly requires trustworthy databases for XRPCS and/or reliable predictions of inner-shell ionization theories as periodically evaluated in Monte Carlo Geant4 simulations.
Purpose: The purpose of the study is to present 1) a review of the PIXE technique and its applications, and 2) universal experimental and theoretical fits to exiting databases for K and L-shell XRPCS.
Goals: The goal is to check if the theory is accurate across the periodic table of elements and a large range of projectile energies, equally comprehensive databases are essential and a universal fit for them is desired. Those fits should be in terms of a variable by which XRPCS are scaled with a minimum of adjustable parameters. L-shell XRPCS for proton energies 26 eV ≤ E1≤1 GeV and all elements with 24 ≤ Z ≤ 95 as compiled by Miranda and Lapicki 2014 are in excellent agreement with the universal fit to these data. Only 0.7% of data/fit ratios differ from 1.0 by more than a factor of 4; merely 3.4% differ by more than a factor of 2.
Conclusions: The versatility of the PIXE technique and its application will be demonstrated. It will be shown how universalexperimental and theoretical fits to XRPCS serve to set reliable prediction across projectile energies and a wide range of target elements.
V P Maslov
National Research University, Russia
Title: Transition from mesoscopy of low levels of the liquid-drop model of nucleus to macroscopy of critical mass of uranium and plutonium with regard to partition theory
Time : 14:50-15:15
Biography:
V P Maslov is a Professor of National Research University Higher School of Economics (School of Applied Mathematics). In 1984, he was elected to full membership of the Mathematical section of Russian Academy of Sciences directly, without passing through the corresponding member stage. He has published over 600 papers and over 20 monographs. He introduced a series of important notions of which Maslov-type index theory, Maslov classes, Maslov form, Maslov correction, Maslov WKB method, Maslov cycle, Maslov dequantization are best known.
Abstract:
The author changed and supplemented the standard scheme of partitions of integers in number theory to make it completely concur with the Bohr–Kalckar correspondence principle. We revise the partition theory of integers in accordance with the Bohr–Kalkar correspondence principle (1938) relating the physical notion of nucleus to number theory. This principle has given rise to a series of papers. We use results due to Auluck–Kothari (1946), Agarwala–Auluck (1951), and Srivatsan–Murthy–Bhaduri (2006). We understand entropy as the natural logarithm of the number p (M) of partitions of with repeated summands and q(M) of partitions without repeated summands. The transition of ln p (M) to ln q (M) through mesoscopic values of is studied. In order to make the analogy between the the atomic nucleus and the theory of partitions of natural numbers more complete, to the notion of defect of mass author assigns the “defect” of any real number (i.e., the fractional value that must be added to a in order to obtain the next integer). This allows to carry over the Einstein relation between mass and energy to a relation between the natural numbers M and N, where N is the number of summands in the partition of the given number M into natural summands, as well as to define a forbidding factor for the number M, and apply this to the Bohr–Kalckar model of heavy atomic nuclei and to the calculation of the maximal number of nucleons in the nucleus.
S P Avdeyev
Joint Institute for Nuclear Research, Russia
Title: Source velocity at relativistic beams of 4He
Time : 15:15-15:40
Biography:
S P Avdeyev has his expertise in Nuclear Physics. He has completed his PhD from Joint Institute for Nuclear Research and Doctor of Science (Phys. and Math.) in 2007. He is a Research Team Leader focusing on nuclear multifragmentation at Joint Institute for Nuclear Research.
Abstract:
The main decay mode of very excited nuclei (E*≥4 MeV/nucleon) is copious emission of intermediate mass fragments (IMF), which are heavier than α-particles but lighter than fission fragments. An effective way to produce hot nuclei is reactions induced by heavy ions with energies up to hundreds of MeV per nucleon. But in this case the heating of the nuclei may be accompanied by compression, rotation, and shape distortion, which can essentially influence the decay properties of hot nuclei. The picture becomes clearer when light relativistic projectiles are used. In this case, fragments are emitted by only one source - the slowly moving target spectator. Its excitation energy is almost entirely thermal. Light relativistic projectiles provide therefore a unique possibility for investigating thermal multifragmentation. The decay properties of hot nuclei are well described by statistical models of multifragmentation and this can be considered as an indication that the system is in thermal equilibrium or at least close to that. In the present work the source characteristics of multifragmentation are investigated for the 4He+Au collisions at 4 and 14.6 GeV using the 4π FASA detector on Dubna superconducting accelerator Nuclotron. Evidence that at least kinetic equilibrium of the system is achieved before fragmentation take place is found in the results of rapidity analyses. Decrease in energy of the incident particles from 14.6 GeV to 4 GeV leads to increases momentum transfer and source velocities. Data in 4He (14.6 GeV)+Au reaction are consistent with the INC+SMM calculations and can be described by one source with fixed velocity. There is broad range source velocities distribution in case of 4He (4 GeV)+Au where the speed of the source increases with IMF energy that is not predicted by INC+SMM.
Ushasi Datta
Saha Institute of Nuclear Physics, India
Title: How atomic nucleus behaves around its limit of existence and its impact on explosive burning in the cosmos
Time : 15:40-16:05
Biography:
Ushasi Datta has expertise in experimental Nuclear Physics. She has completed her PhD from University of Kolkata and is working as a Professor at Saha Institute of Nuclear Physics, India. She leads many national and international projects. Her interest is to understand quantum many body systems via strong and weak interaction. Her research topics are disappearance of magic shell gap in the neutron-rich nuclei, modification of shell structure near drip-line, ground state configuration of neutron-rich nuclei, exotic shapes, exotic decay near proton-drip line, resonance states, cluster structure, quantum phase transition, fusion process near drip line, capture cross-section relevant to explosive burning scenario, neutron-skin, neutron star, active and sterile neutrino etc. She worked at GSI, Darmstadt for five years as a Visiting Scientist and Alexander Von Humboldt fellow. She has published more than hundred in peer review international journals with citations of 2000.
Abstract:
Even after 100 years of discovery of the atomic nucleus by Rutherford, the limits of the existence of the nuclei are still uncertain. This is due to lack of proper understanding of the nature of interactions that bind atomic nuclei. The atomic nucleus is a complex quantum many-body system but it's simple behavior can be explained by a mean nuclear field, containing many ingredients of the nucleon-nucleon interactions. The characteristics of that are the shell gaps at magic numbers, explained by Mayer and Jensen. The study of Nuclear Shell structure around the drip line and validation of theoretical prediction with the data may provide important information on nucleon-nucleon interaction. This may play key role in understanding the limits of its existence. The Coulomb breakup is an exclusive tool for probing the quantum states of valence nucleon. We have investigated the ground-state properties of neutron-rich nuclei around N~20 using this method via kinematical complete measurement at GSI, Darmstadt. Very clear evidences have been observed for the breakdown and merging of long cherished magic shell gaps at N=20, 28. The nuclei around the drip-line are short lived and naturally do not exist on the earth. But surprisingly, evanescent rare isotopes imprint their existence in supernovae and other stellar explosive scenarios (rp, r-process etc.). To understand those processes and evaluation of elements, one has to create those nuclei in the laboratory to explore specific-properties. Due to their fleeting existence, indirect measurements are often only possible access to the information which are valuable inputs to the model for star evaluation process. Neutron star, remnant of supernovae is the densest matter, observed in cosmos. To understand that state of matter, some valuable properties of neutron-rich nuclei are key issues. I shall discuss our achievements related to above mentioned facts using RIB in worldwide scenario.
- Video Presentations
Location: Paramount Room
Session Introduction
Alexander Papash
Karlsruhe Institute of Technology, Germany
Title: Long term beam dynamics and ion kinetics in ultra-low energy storage rings
Time : 16:25-16:40
Biography:
Alexander Papash is a Research Scientist (PhD) and he is expert in Accelerator Physics. He was graduated from the Physical Department of Kiev State University (Ukraine). He has more than 30 years of research and engineering experience in design and operation of scientific and commercial accelerators worldwide, namely, at Karlsruhe Institute of Technology and Max-Planck Institute of Nuclear Physics (Heidelberg, Germany), Joint Institute for Nuclear Research (Dubna, Russia), Kiev Institute for Nuclear Research (Ukraine), Canadian National Meson Facility TRIUMF (Vancouver) and Laboratorio Nucleare del Sud (Catania, Italy).
Abstract:
Electrostatic storage rings operate at very low energies in the keV range and have proven to be invaluable tools for atomic and molecular physics. Because of the mass independence of electric rigidity, these machines are able to store a wide range of different particles, from light ions to heavy singly charged bio-molecules, opening up unique research opportunities. However, earlier measurements have shown strong limitations on beam intensity, fast growth of beam size and decay of ion current, reduced lifetime of ion beam. The nature of these effects has not been fully understood. Also a large variety of experiments in future generation ultra-low energy storage and decelerator facilities including in-ring collision studies with a reaction microscope require a clear understanding of the physical processes involved into the operation of such rings. Nonlinear and long-term beam dynamics studies in ultra-low energy storage rings are presented on the examples of a number of existing and planned electrostatic storage ring facilities. The results from simulations were benchmarked against experimental data of beam losses in the ELISA storage ring [S.P. Møller et al., Proceed of the European Particle Accelerator Conference, Vienna, 2000, pp. 788–790)]. It was shown [1,2,3] that decay of beam intensity is mainly caused by ion losses on ring aperture due to multiple scattering on residual gas. Beam is lost on electrostatic elements and collimators due to small ring acceptance. Rate of beam losses increases at high intensities because of the intra-beam scattering effect adds to vacuum losses. Detailed investigations into ion kinetics, under consideration of effects from electron cooling and multiple scattering of the beam on a supersonic gas jet targets, were carried out and yields a consistent explanation of the physical effects in a whole class of ultra-low energy storage rings. The lifetime, equilibrium momentum spread, and equilibrium lateral spread during collisions with the target are estimated. Based on computer simulations, the conditions for stable ring operation with an extremely low-emittance beam are predicted. Finally, results from studies into the interaction of ultra-low energy ions with a gas jet target are summarized.
Shahpoor Saeidian
Institute for Advanced Studies in Basic Sciences, Iran
Title: Few-body physics of quasi-one dimensional atomic gases
Time : 16:40-16:55
Biography:
Shahpoor Saeidian has his expertise in ultracold atomic physics. He has completed his PhD at from University of Heidelberg, Germany. He is Assistant Professor and Director of a research team focusing on Ultracold Atomic Physics at Institute for Advanced Studies in Basic Sciences, Iran.
Abstract:
We investigate a theoretical method to study the quantum dynamics of ultracold atomic gases inside an atomic waveguide. Ultracold atomic gases are that are maintained at temperatures below some tenths of microkelvins. At these temperatures, the thermal de Broglie wavelength of the atoms are of the order of the atomic distances, therefore the quantum mechanical properties of the system become important. Due to the excellent experimental control of their trapping as well as their interatomic interactions, ultracold atoms have a variety of applications. Of particular interest are quasi-1D gases. By employing optical dipole traps or atom chips, we can fabricate the so-called quasi-1D gas in which the atoms are frozen to occupy a few lowest quantum states of a transverse 2D confinement potential such that in these directions the characteristic lengths are of the order of the atomic de Broglie wavelength. The quantum dynamics of these systems is strongly influenced by the geometry of the confinement potential and therefore behaves very differently compared to gases in free space. As an example, in contradiction with spin-statistics in free space, the “Fermi-Bose duality” maps strongly interacting bosons to weakly interacting fermions and vice versa. These systems are expected to play an important role, for example in quantum computing, atom interferometries, and studying novel 1D many-body states. Most of the many-body properties of gases are the outcome of atom-atom scattering events. Of particular interest are scattering resonances. For quasi-1D gases, the confinement potential of the waveguide leads to the so-called confinement induced resonance (CIR). In a bosonic gas in the vicinity of CIR, the atom-atom coupling strength diverges, resulting in the phase transition of the gas to the impenetrable regime (known as the TG gas). In this regime the bosons repel each other strongly and behave like fermions. We analyze the elastic as well as inelastic multi-channel scattering of two ultracold atoms under harmonic confinement. For elastic scattering, the effects of the interatomic potential and the waveguide anisotropy on the width and position of the CIR are studied.