Day 2 :
Keynote Forum
Jianguo Huang
Beijing Institute of Spacecraft Environmental Engineering, China
Keynote: Spacecraft charging in low earth orbit plasma driven by high voltage solar arrays in low earth orbit plasma
Time : 10:00-10:45
Biography:
Jianguo Huang has completed his PhD from Institute of Physics, Chinese Academy of Sciences. He is the Senior Expert of Spacecraft Environment Engineering, member of expert database of Ministry of Science and Technology, China and referee expert of China Natural Fund Committee. He mainly specializes in space environment and its interaction with spacecraft. He has published more than 70 papers in reputed journals and has been serving as an Editorial Board Member of several academic journals.
Abstract:
Space vehicles immersed in space plasma are generally charged to certain potentials, which usually depend on the local plasma temperature and exposed material properties. Generally speaking, the spacecraft running in low earth orbit will experience weak surface charging due to the fact that the low earth orbit pass through the ionosphere, which is composed of dense and cold plasma with typical electron temperature of 0.2 eV. However, application of high voltage solar arrays can induce significant spacecraft charging in some situations, two typical charging events, rapid charging and normal charging, have been observed on international space station, both of which are induced by the interaction of high voltage solar arrays with space plasma and occur at exit from eclipse. For the rapid charging, with typical spikes of floating potential up to 70 volts have been observed frequently in the international space station. Such a charging situation is threatening to the safety of the space station. In this paper, the spacecraft charging driven by high voltage solar arrays is modeled. The results show that the rapid and normal charging are two different stages of the same charging process. The rapid charging, the initial stage, is a non-equilibrium charging driven by the sudden solar panel voltage switch-on at eclipse exit, in which case the charging of the cover glasses by the ambient plasma can’t respond quickly enough to block the electron collection by the solar arrays effectively. As the charging reaches equilibrium, it displays as a normal charging event with smaller floating potential. The characteristics and trends of both the rapid and normal charging are presented by calculation with international space station configurations and the results agree well with observations.
Keynote Forum
Qiu-he Peng
Nanjing University, China
Keynote: The evidence of magnetic monopoles by astronomical observation and its astrophysical implication
Time : 10:45-11:30
Biography:
Jianguo Huang has completed his PhD from Institute of Physics, Chinese Academy of Sciences. He is the Senior Expert of Spacecraft Environment Engineering, member of expert database of Ministry of Science and Technology, China and referee expert of China Natural Fund Committee. He mainly specializes in space environment and its interaction with spacecraft. He has published more than 70 papers in reputed journals and has been serving as an Editorial Board Member of several academic journals.
Abstract:
A key observation has been reported in 2013: An abnormally strong radial magnetic field near the GC is discovered. Firstly, we demonstrate that the radiations observed from the GC are hardly emitted by the gas of accretion disk which is prevented from approaching to the GC by the abnormally strong radial magnetic field and these radiations can't be emitted by the black hole model at the Center. However, the dilemma of the black hole model at the GC be naturally solved in our model of super massive object with Magnetic Monopoles (MMs). Three predictions in our model are quantitatively in agreement with observations: It could be an astronomical observational evidence of the existence of MMs and no black hole is at the GC. Besides, making use of both the estimations for the space flux of MMs and nucleon decay catalyzed by MMs (called the RC effect) to obtain the luminosity of celestial objects by the RC effect. In terms of the formula for this RC luminosity we are able to present a unified treatment for various kinds of core collapsed supernovae , SNII, SNIb, SNIc, SLSN ( Super Luminous Supernova ) and the production mechanism for γ ray burst. The remnant of the supernova explosion is a neutron star rather than a black hole, regardless of the mass of the progenitor of the supernova. Besides, the heat source of the Earth’s core as well as the energy source needed for the white dwarf interior is the same mechanism of the energy source as supernova. This unified model can also be used to reasonably explain the possible association of the shot γ ray burst detected by the Fermi γ ray Burst Monitoring Satellite (GBM) with the September 2015 LIGO gravitational wave event GW150914. We propose that the physical mechanism of Hot Big Bang of the Universe is also nucleons decay driven by the magnetic monopoles, similar to the supernova explosion.
- Plasma Physics | Dusty & Grain Plasma | Thermal Plasma | Atomic & Molecular Physics | Nuclear Physics
Location: Hermitage 2
Chair
John Owen Roberts
Open University, UK
Session Introduction
Aline I Maalouf
The Australian National University, Australia
Title: Why quantum control
Time : 11:30-12:00
Biography:
Aline I. Maalouf received the B.Sc. and M.Sc. degrees in electrical engineering (with honors) from Balamand University, Lebanon, the M.Phil. degree in control engineering from Cambridge University, Cambridge, U.K., and the Ph.D. degree in quantum control from the University of New South Wales at Australian Defence Force Academy, Australia. Her main research interests are in robust control theory, quantum control theory, and stochastic control theory. She received the ALMA prize from Balamand University, a Cambridge Overseas Trust Scholarship (in collaboration with the Said Foundation), a University International Postgraduate Award from the University of New South Wales, and was a Finalist for the Student Best Paper Award at the American Control Conference in 2009. She is a Fellow of the Cambridge Overseas Trust. She is currently a research associate and a Lecturer at the Australian National University.
Abstract:
As experimental quantum technology continues to improve, the idea of manipulating microscale quantum processes rather than just observing them is rapidly gaining ground. In particular, the manipulation of quantum systems using continuous measurement and feedback control has generated increasing interest in the last few years due to its potential applications in metrology, communications and other quantum technologies. Also, the area of quantum control is of theoretical interest, since it connects the well-developed field of classical optimal control theory to fundamental questions regarding the structure of information and disturbances in quantum mechanics. Therefore, significant interest has emerged in the area of quantum feedback control systems.
Extending classical control theory to the quantum domain; i.e., to physical systems whose behavior is not governed by classical physics but dominated by quantum effects, has become an important area of research. It is also an essential prerequisite for the development of novel technologies such as quantum information processing, as well as new applications in quantum optics, quantum electronics and quantum chemistry.
The most effective strategies in classical control applications involve feedback control. However, the implementation of classical feedback control for quantum systems poses severe challenges since quantum measurements tend to destroy the state of the system (wave-packet reduction).
Nevertheless, the possibility of continuous monitoring and manipulation on a natural time-scale has recently become realistic for some quantum systems. This may be viewed as a first step in the direction of closing the gap between quantum feedback control and classical control theory.
In this talk, I will define robust and optimal quantum control which are at the core of feedback control from an engineering perspective and go through my own contributions in that domain.
Shujaht Bukhari
University of Azad Jammu and Kashmir, Pakistan
Title: Twisted dust-acoustic waves and kinetic instability in a dusty plasma
Time : 12:00-12:30
Biography:
Shujaht Bukhari has his expertise in the study of “Laser-Plasma Collective Processes” and “Waves and instabilities in Space & Astrophysical Complex Plasmas” with non-planner or helical wavefronts owing to the finite orbital angular momentum states. He supervised many students at BS and MS level programs. Currently he is working in the Department of Physics, University of Azad Jammu and Kashmir.
Abstract:
The kinetic instability of twisted dust-acoustic (DA) wave with distinct orbital angular momentum (OAM) states is studied in an unmagnetized multi-components dusty plasma. For this purpose, the linearized Vlasov-Poisson equations are solved together by expressing the perturbed distribution function and electrostatic potential in terms of Laguerre-Gauss functions or solutions. A generalized plasma dielectric constant is derived and the existence conditions for damping/growth rates are discussed showing significant modifications in twisted dusty modes as compared to straight propagating modes. The impact of streaming speed and twist parameter are numerically examined on the growth rate instability. It has been found that parametric variation significantly modifies the threshold conditions and associated growth rate instability of twisted DA waves. The relevance of the present results to interstellar dust clouds and in laboratory plasmas is illustrated, where massive dust grains follow a Maxwellian distribution in addition to streaming electrons and non-streaming ions.
Muhammad Rafique
University of Azad Jammu and Kashmir, Pakistan
Title: Kinetic study of two temperature twisted ion acoustic waves
Time : 12:30-13:00
Biography:
Prof. Dr. Muhammad Rafique has completed his PhD at the age of 33 years from Pakistan Institute of Engineering and Applied Sciences and postdoctoral studies from University of Michigan USA. He is the director Quality Enhancement Cell at the University of Azad Jammu & Kashmir, also he has served as chairman/HoD of the Department of Physics from 2013 to 2016. He has published more than 100 papers in reputed journals and has been serving as an editorial board member of repute.
Abstract:
The electrostatic twisted ion acoustic wave (TIAW) with two components (hot and cold) of positive ions having distinct finite orbital angular momentum (OAM) states is investigated in an un-magnetized collision less electron-ion plasma. The Vlasov-Poisson coupled set of equation is used for the analysis of dynamics of TIAW. The Laguerre Gaussian solutions are employed on perturbed quantities owing to the helical phase structures. The dispersion properties and Landau damping rates of TIAW are analyzed both analytically and numerically. It is found that wave frequency and Landau damping rate are significantly modified in the presence of finite states of OAM. It is shown that twist parameter, hot to cold ion density and temperature ratios have significant influence on damping rate and wave frequency. The result will be useful in considering laser matter interaction and particle transport in laboratory plasmas.
Punit Kumar
University of Lucknow, India
Title: Filamentation of a short laser pulse in magnetized quantum plasma with spin polarization
Biography:
Punit Kumar has expertise in Free Electron Lasers (FEL) and Plasma Physics. He introduced ion-channel guiding in FEL. He worked on laser-plasma interaction and studied wakefield and ponderomotive acceleration, parametric instabilities and other nonlinear effects. Currently, he is working on quantum plasma and is interested in analyzing the effects of spin polarization of electrons produced under the influence of high magnetic fields.
Abstract:
The study of electron beam-wave interaction in the presence of background plasma has attracted a lot of interest over the past few decades. This interaction has widespread application in a number of area including Inertial Confinement Fusion (ICF), plasma microwave electronics, x-ray burst sources, free electron lasers, cyclotron auto resonance maser oscillator, the solar corona and accelerator physics. As is well known that when an electron beam propagates in a plasma, it will induce a return current in the plasma, carried by plasma electrons, to keep neutralization of the system. The interaction results in filamentation. In plasmas, when the de Broglie wavelength of the charge carriers is comparable to the dimension of the plasma system, quantum mechanical effects are expected to play a major role in the behavior of charged plasma particles. The QHD model, which consists of a set of equations dealing with the transport of charge, momentum and energy in a plasma is the most widely used model to describe quantum effects in plasma. In recent years, quantum effects have proved to play a crucial role in ultra-small electronic devices, laser plasmas and dense astrophysical plasmas. Filamentation in quantum plasma have been studied by various authors but all the previous studies considered electrons as a single fluid of macroscopically averaged spin-1/2 plasma. The earlier papers did not show a full picture and didn’t take spin-up and spin-down interaction force into account. Very recently, a modified Separate Spin Evolution (SSE) treatment of electrons in accordance with Pauli equation has been developed. In the present paper, using the modified SSE-QHD model the filamentation of a short laser pulse in a magnetized quantum plasma is presented. Spin-up and spin-down electrons have been taken to be separate species of particles and spin-spin interaction picture has been developed. The effects of quantum Bohm potential, electron Fermi pressure and spin have also been taken into account. The direction of the external field has been taken to be along the direction of electron beam propagation in the first case and oblique in the second case. The dispersion for both the cases has been obtained and growth rate evaluated. The numerical analysis for growth rate has been carried out. The results of both the cases have been compared and analyzed. Comparison has also been done with earlier studies and the difference is critically analyzed and interpreted.
Avnindra Kumar Singh
University of Delhi, India
Title: Spectroscopic study of EUV and SXR transitions of Cu XIX with plasma parameters
Biography:
Avnindra Kumar Singh has completed his PhD from University of Delhi while serving as an Associate Professor in the Department of Physics, Deen Dayal Upadhyaya College, University of Delhi. He has completed his Postdoctoral Studies from Armagh Observatory, Northern Ireland, UK in 2010. He has published more than 35 papers in reputed journals.
Abstract:
Extensive and elaborate theoretical computations of Cu XIX have been performed by employing Multi-Configuration Dirac-Fock (MCDF) method. We have presented energy levels and radiative data such as, transition wavelengths, radiative rates, oscillator strengths and line strengths for electric dipole (E1) transitions in Na-like Cu. For other types of transitions, namely magnetic dipole (M1), electric quadrupole (E2) and magnetic quadrupole (M2), only the A-values are listed. We have also discussed the importance and the effect of Valence-Valence (VV) and Core-Valence (CV) correlations on the excitation energies in graphical as well as in tabular form. The accuracies of the presented levels, wavelengths, transition rates and lifetimes are assessed by comparing them to available experimental and other theoretical results. Analogous calculations have been carried out by using Flexible Atomic Code (FAC) based on self-consistent Dirac-Fock-Slater iteration method. QED corrections due to vacuum polarization and self-energy effects and Breit correction due to the exchange of virtual photons between two electrons are fully considered and their effects on the energy levels are studied graphically. The fine-structure energy levels have also been reported by using the Configuration Interaction (CIV3) technique. An inter-comparison among three independent calculations helps us in assessing the credibility and integrity of our reported data. Additionally, we have shown the variation of the line intensity ratios and electron density with plasma temperature graphically for Cu XIX. We have also identified Extreme Ultraviolet (EUV) and Soft X-ray (SXR) transitions and believe that our reported results may be beneficial in space and laboratory plasma research.