Scientific Program

Conference Series Ltd invites all the participants across the globe to attend 5th International Conference on Theoretical and Applied Physics Vienna, Austria.

Day 1 :

Keynote Forum

Ling Jun Wang

University of Tennessee at Chattanooga, USA

Keynote: Unification of gravitational and electromagnetic forces

Time : 09:30-10:05

Conference Series Applied Physics 2018 International Conference Keynote Speaker Ling Jun Wang photo
Biography:

Ling Jung Wang is a physics professor at University of Tennessee at Chattanooga of USA. His major interest is in theoretical physics (particle physics, relativity and cosmology). He has many fundamental issues with relativity and the Big Bang cosmology. The details can be found in his publication “Hundred years of general relativity – a critical view” and other related publications. Ling Jun Wang have proposed an alternative theory “Dispersive Extinction Theory (DET)” to explain the cosmic red shift instead of ascribing it as due to the expansion of the universe [Physics Essays, 18, 2 (2005). DET allows a stable universe infinite in space and time. My most recent work is “Unification of gravitational and electromagnetic fields” which is published in Physics Essays 31, 1(2018).

 

Abstract:

It has been a dream of physicists to unify all the fundamental forces over at least a century. The Grand Unification Theory (GUT) requires an unbelievably high energy in the order of 1016 GeV and an accelerator larger than the solar system. It is apparently beyond our reach in the fore seeable future. The last stage of this dream is the Theory of Everything (ToE), which includes the gravitational force in its unification, which requires an even higher energy—known as the Plank energy scale, about 1000 times higher than the GUT energy scale. Moreover, it has been realized that general relativity is incompatible with quantum mechanics. The approach of describing gravity in the framework of quantum field theory fails at short distances of the order of the Planck length. Recently, we have developed a theory with mathematical rigor to unify the gravitational and the electromagnetic forces strictly within the classical framework by generalizing Newton’s law of gravitation to include a dynamic term inferred from the Lorentz force of electromagnetic interaction. An entire dynamic theory including a wave equation of gravitation is developed without any additional ad hoc hypothesis. The wave equation and its solution naturally solve the mystery of action-at-distance. It has been discovered that the inverse square law of the static and the dynamic forces is the result of the cons. It has been shown that the inverse square law of the static and the dynamic forces is the result of the conservation of mass (Gauss’s Law) and the total momentum (Wang’s Law). The gravitational and the electromagnetic forces are unified in the sense that these two forces and their propagation can be described by exactly the same set of equations.

Keynote Forum

Debabrata Saha

Northern Virginia Section of IEEE Information Theory Society, USA

Keynote: Natural field: A new fundamental entity of nature

Time : 10:05-10:40

Conference Series Applied Physics 2018 International Conference Keynote Speaker Debabrata Saha photo
Biography:

Debabrata Saha is a Research Scientist who recently completed a teaching assignment in NIT, Karnataka, India as an Adjunct Professor. Before this, he taught for 21 years as Tenured Member of a faculty, and, thereafter, worked as President of a consulting firm, both in USA. He is a former Chairman of Washington D.C.–Northern Virginia Section of IEEE Information Theory Society, USA. His academic background includes degrees in Science– BSc, Physics (Calcutta University), Technology – BTech, Electronics (Calcutta University), Applied Science – MASc, Communication (University of Toronto), and Engineering =–PhD, Computer, Information and Control Engineering (University of Michigan).

Abstract:

Natural field is a recently found new fundamental entity of nature. It particularly distinguishes itself from existing four fundamentals, namely, gravitation, coulomb, strong and weak forces in its ability of causing self-interference. It is established that de Broglie’s wave particle duality is incorrect and wave associated with any moving particle is non-existent. In addition, contemporary Physics falls short of accounting for a set of repeated experimental evidence. This set that remains unexplained lies in, (a) our inability of last two thousand years in deriving the law of reflection of light starting from the root cause, (b) the problem associated with splitting of light ray at a refracting surface where light ray divides, but light quanta cannot divide without an alteration in frequency, (c) failure of wave theory of light in explaining double-slit interference pattern, observed in recent decade, with photons passing through one slit at a time and not both slits simultaneously, and (d) lack of explanation for Davisson-Germer’s electron diffraction after the realization that de Broglie wave is non-existent. Natural field is found in a search for mitigating these shortcomings of contemporary physics. Postulate of natural field along with related theoretic analyses is supported by five independent set of repeated experimental results, namely, electron diffraction, reflection and refraction of light, splitting of light ray at a refracting surface, double-slit interference pattern with single photon, and Braggs’ X-ray diffraction as well. Natural field exhibits characteristics common to both light and matter particles. It provides a unification of matter and light.

Conference Series Applied Physics 2018 International Conference Keynote Speaker Vasily Yu Belashov photo
Biography:

Vasily Yu Belashov, has a PhD in Radiophysics and a DSci in Physics and Mathematics. His main fields of research interest are theory and numerical simulation of the dynamics of multidimensional nonlinear waves, solitons and vortex structures in plasmas and other dispersive media. Presently, he is a Chief Scientist and Professor at the Kazan Federal University. He is the author of 310 publications including seven monographs. He has authoured the follwoing books: “Solitary Waves in Dispersive Complex Media: Theory, Simulation, Applications”, Springer-Verlag GmbH, 2005 and “Solitons: Theory, Simulation, Applications”, Kazan, Publishing Center “School, 2016.

Abstract:

The problem of classification of the multidimensional nonlinear waves and solitons forming on the low-frequency branch of oscillations in complex continuous media with dispersion, including plasmas and fluids, is studied analytically on the basis of the generalized Kadomtsev-Petviashvili (GKP) equation (as partial case of the Belashov-Karpman (BK) system) which takes into account the generalizations relevant to various complex physical media, associated with the effects of high-order dispersion corrections. To construct the classification of solutions on their types, we consider the dynamical systems associated with the GKP equation and study the structure of these solutions using the methods of qualitative analysis and analysis of the solutions’ asymptotics. We also present some considerations on constructing of the phase portraits of the systems in the 8-dimensional phase space for the GKP equation on the basis of the results of qualitative analysis of the generalized equations of the KdV-class. As a result, we have constructed a classification of possible multidimensional solutions for the GKP system. This is consistent representation of both, the early known and new original results obtained by the author and also some generalizations in theory of the nonlinear waves and solitons in complex dispersive media.

  • Theoretical Physics | Experimental Physics | Computational Physics | Plasma Physics | Supercondutivity
Location: Flemings Room 6

Chair

Ling Jun Wang

University of Tennessee at Chattanooga, USA

Co-Chair

Vasily Yu Belashov

Kazan Federal University, Russia

Session Introduction

Johannes Gruenwald

Gruenwald Laboratories, Austria

Title: Theory and applications of inverted fireballs

Time : 11:45-12:05

Biography:

Johannes Gruenwald obtained his master degree in physics from the University of Graz in 2008 and his PhD in physics from the University of Innsbruck in 2012. He has authored or co-authored more than 35 publications in theoretical, experimental and applied plasma physics and technology. His fields of interest include plasma instabilities, fusion physics, plasma coating technologies and the application of plasmas for space technologies. Johannes Gruenwald was guest researcher in several research facilities and universities across five countries. He is the CEO and founder of Gruenwald Laboratories and the editor-in-chief of the Journal of Technological and Space Plasmas.

Abstract:

Inverted fireballs have been proven to be a viable tool for large area surface modifications and for a direct conversion from a DC input signal to an RF output signal. Their suitability for surface modifications in general and for deposition technologies in particular is owed to their very homogeneous plasma potential and their high charge densities. This talk will outline
theoretical investigations into inverted fireballs, such as analytical models and particle-in-cell simulations and the application of these findings to technologically relevant topics. Recent findings that describe in detail how these plasma phenomena can be utilized will be shown. Furthermore, it will be demonstrated that inverted FBs exhibit a number of plasma instabilities, but they can be stabilized over a long period of time, which is necessary for their utilization in the industry. It will also be outlined in this talk where the borders of fireball research are at the moment and what needs to be done in order to gain a deeper scientific understanding in the future.

Recent Publications:
1. D Levko and J Gruenwald (2017) On the energy deposition into the plasma for an inverted fireball geometry. Physics of Plasmas 24(10):103519.
2. P Knoll et al. (2016) PECVD of carbon by inverted fireballs: from sputtering, bias enhanced nucleation to deposition. Diamond and Related Materials. 65:96–104.
3. J Gruenwald (2014) On the dispersion relation of the transit time instability in inverted fireballs. Physics of Plasmas 21(8):082109.
4. R L Stenzel et al. (2011) Transit time instabilities in an inverted fireball. II. Mode jumping and nonlinearities. Physics of Plasmas 18(1):012105.

Biography:

Hiqmet Kamberaj has completed his PhD in 2005 from Manchester Metropolitan University and Post-doctoral studies from University of Minnesota, Arizona State University and National Institute of Nanotechnology at University of Edmonton. He is an Associate Professor at International Balkan University and the Acting Dean of the Faculty of Engineering. He has published around 20 papers in reputed journals and has been serving as an Editorial Board Member and Ad-Hoc Reviewer of repute.

Abstract:

In this study, we investigate the interactions and analyze associative behaviour at the interface between protein and RNA. In this study, we have combined molecular dynamics simulation and information theoretic measures, such as transfer entropy to investigate the driving forces at the interface of complex biomolecular systems. The modular architecture of binding site may greatly simplify the design of new molecular systems interactions and provides a feasible view of how these interactions evolve. Combining complex information theoretic measures and free-energy calculations, we show that identification of the dominant contributions to the free energy of complex interactions can guide experiments aimed at the design of protein interaction inhibitors and provide a stepping-stone to important applications such as interface redesign.

Biography:

Vladimir G Plekhanov was graduated Tartu State University in 1968, PhD. (Physics and Mathematics, 1972), Doctor of Science (Physics and Mathematics, 1982). Main interest fields: the origin of the mass (quantization of matter) as well as the experimental manifestation of the strong nuclear interaction in the spectroscopy of solids. He is author approximately 200 publications both in English and Russian. Main books:
1. Isotope Effects in Solid State Physics (Academic Press, San Diego, 2001).
2. Isotope - Based Quantum Information (Springer, Heidelberg, 2012).
3. Isotopes in Condensed Matter (Springer, Heidelberg, 2013).
4. Isotope Effect - Macroscopical Manifestation of the Strong Interaction (Lambert Academic Publishing, Deutschland, 2017) (in Russian).

Abstract:

It is well - known that the interaction binding quarks into hadrons is called the strong interaction. It holds protons and neutrons together to form nuclei. For the strong interaction, gluons are the exchange particles that couple to the color charge of quarks. There are a common place in modern physics that the strong force does not act on leptons (electrons, positrons, muons and neutrinos). Our experimental results show the violation of this strong conclusions. Up to present time macroscopic manifestation of the strong nuclear interaction are restricted to radioactivity and the release of nuclear energy. Our report is devoted to the description of the significantly new kind manifestation of the strong force. It will be shown that an activation of the strong interaction by adding of one neutron to the nucleus causes the global reconstruction of the macroscopic characteristics of solids. We have studied the low - temperature optical spectra (luminescence -- Fig. 1 and reflection -- Fig. 2) of the LiHx D1-x , 0 ≤ 1 ≤ 0 crystals which are differ by term of one neutron from each other. In dielectrics crystals an electron from valence band is excited into the conduction band. The attractive Coulomb potential btween the missing electron in valence band, which can be ragarded as a positively hole, and the electron in conduction band forms exciton which energy En=1s (LiD) crystals are large - radius excitons [2]. In experiments we used the samples with clean surface cleaving in the bath of helium cryostat with normal or superfluid liquid helium. Exciton luminescence is observed when studied crystals are excited in the midst of fundamental absorption [3]. The spectrum of free exciton photoluminescence of LiH (LiD) crystals cleaved in superfluid helium consists of narrow phonoless emission line and its broader phonon replicas which arise due to radiative annihilation of excitons with the production of one to five LO phonons ( in Fig. 1 it shows only two LO phonons).

Mikhail A Mochalov

Russian Federal Nuclear Center, Russia

Title: Quasi-isentropic compressibility of deuterium at pressure region of ~12 TPa

Time : 12:45-13:05

Biography:

Mikhail A Mochalov has an ScD Degree in Physics and Mathematics. He is a High-Quality Expert in experimental investigations of thermal physical properties for plasma of cryogenic liquids (such as nitrogen, argon, krypton, and xenon), gaseous helium and deuterium at shock compression and quasi-isentropic compression in the megabar range of pressures. His obtained data are well-known in Russia and other countries. The data are unique and correspond to the world level of investigations in physics of high energy densities.

Abstract:

We report on the experimental results on the quasi-isentropic compressibility of a strongly non-ideal deuterium plasma compressed to the density ρ≈10 g/cc by pressure Р=11400 GPa (114 Mbar) on a setup of spherical geometry. We describe the characteristics of the experimental setup, as well as the methods for the diagnostics and interpretation of the experimental results. The trajectory of metal shells that compress the deuterium plasma was detected using powerful pulsed X-ray sources with maximal electron energy of up to 60 MeV. The value of the plasma density ρ≈10 g/cc was determined from the measured value of the shell radius at the instant that it was stopped. The pressure of the compressed plasma was determined using gas dynamic calculations, taking into account the actual characteristics of the experimental setup. In the laboratory experiment on multiple shock loading of gaseous deuterium was achieved a state very close to that of planet-giants of the solar system, e.g. Jupiter and Saturn.

Valentina Markova Kirilova

Bulgarian Academy of Sciences, Bulgaria

Title: About the new axioms and laws

Time : 14:05-14:25

Biography:

Valentina Markova Kirilova graduated from the Technical University of Sofia in 1981 as a regular training and also from St. Kliment Ohridski University of Sofia, specializing in Mathematics and Informatics as distance learning. She defended her Doctoral Dissertation and received a PhD Degree from the Scientific Institute from the Ministry of Military Defence in 1990. She now works at the Bulgarian Academy of Sciences, Institute of Mathematics and Informatics as an expert in algebraic encoding of information.

Abstract:

The report describes the new version of the new axioms and laws. This current study continues the development of the expanded field theory by expanding of the theory of the electromagnetic field to a more general theory of the field. This more general theory can cover a much wider area of natural phenomena, even including phenomena such as gravity, free energy and so on. It is known that Maxwell’s laws (1864) are based on a single axiom which says that the even movement (velocity is constant) of an electrical vector E leads to movement in a closed loop (div rot E=0). The author replaces this axiom with a new one, according to which the uneven movement of a vector E leads to an open loop (div rot E≠0) or an open uneven vortex (div Vor E≠0). In this report, two axioms and nine laws lead to some of the following results: movement in a closed loop is replaced with movement in an open loop (vortex). Even movement is replaced with uneven movement in cross or longitudinal, decelerating or accelerating vortices. The decelerating cross vortex generates an accelerating longitudinal vortex in the center of the body of the object through a special transformation (Δ), so movement in 2D leads to movement in 3D. The decelerating vortex emits out cross vortices, while accelerating vortex sucks in cross vortices. The accelerated longitudinal vortices with different accelerations are attracted to each other so that they are inserted into each other and form a gravitational funnel that attracts the environment to itself. The distortion of the surrounding space is just one of the results of the magnitude of the acceleration and of the new quality of the complex design of the longitudinal vortices. Another result is that the timespace within the gravity funnel is opposite to the time–space we live in.

Recent Publications:
1. Markova V (2016) Three space times obtained by combined vortex movements. Intern. Jour. of Current Research 8(9):37826–37832.
2. Markova V (2015) New axioms and structures. Fund. Jour. of Modern Physics 8(1):15–24.
3. Markova V (2015) Gravity structures: essence and properties. Fund. Jour. of Modern Physics 8(2):85–104.

Benedek J Nagy

Wigner Research Centre for Physics, Hungary

Title: Ultrafast photoemission from plasmonic nanotriangles and applications

Time : 14:25-14:45

Biography:

Benedek J Nagy has completed his MSc in Physics at the Budapest University of Technology and Economics in 2014. He started his PhD at the University of Pécs and he is currently an Assistant Research Fellow at the Wigner Research Centre for Physics in the MTA “Lendület” Ultrafast Nano-Optics Group. He spent eight month at the University of Oldenburg in the Ultrafast Nano-Optics Group as a Guest Researcher. He has published more than five papers in reputed journals and was Author and Co- Author to several conference papers.

Abstract:

Ultrafast photoemission proved to be a versatile tool for probing the field enhancement of nanoplasmonic near-fields in the vicinity of nanostructured metal surfaces. Since this new method can be further developed to enable pump-probe studies of nanoplasmonic fields, it is particularly interesting to investigate ultrafast plasmonic photoemission with few-cycle laser pulses, on the characteristic timescale of typical collective plasmon phenomena. To this end, we induced photoemission from different plasmonic nanoparticles with a state-of-the-art Ti: sapphire oscillator, delivering 5.5 fs pulses in a carrierenvelope phase-stabilized manner. The yield, the kinetic energy spectra and angular distribution of photoelectrons were analyzed with the help of a hemispheric electron spectrometer. Ongoing experiments seek to answer whether photoelectron movement on nanometer scale can be governed by the waveform (i.e. the carrier-envelope phase) of few-cycle laser pulses. To this end, asymmetric nanostructures (with respect to the polarization direction of the laser) look the most promising so that the symmetry of the photoemission from the hot spots of the nanoparticles is broken. First, we investigated the kinetic energy spectra of the photoelectrons from nanotriangles with 1-kHz, 40-fs 800-nm pulses delivered by a regenerative amplifier. In this case, a time of flight (TOF) spectrometer can be used for this purpose and after this kind of validation of the field enhancement on the new sample, we can perform the experiments aiming to steer the photoelectrons with the carrier-envelope phase (CEP) of few-cycle laser pulses using an 80-MHz, 5.5-fs 730-nm CEP stabilized laser.

Biography:

Naoum Karchev has completed his PhD from Steklov Mathematical Institute Moscow and Post-doctoral studies from Sofia University, Department of Physics. He has
published 47 papers in Physical Review Letters, Physical Review B: Condensed Matter and Materials Physics, Physical Review D, Journal of Physics: Condensed Matter,
etc.

Abstract:

I report the first study for the impact of the applied electric field on the Cooper pairs prior the superconductivity. The
generalized Maxwell equations are obtained from time-dependent Ginzburg-Landau theory using the first-order formalism
in gauge theory. This formalism is very useful but not popular among solid-state physicists. This is why I gave more details in
the derivation. The results give new insight for the electrodynamics of s-wave superconductors. It is shown that if there are
Cooper pairs above the superconductor critical temperature, the electric field forces the Cooper pairs to Bose condensate and
the onset of the superconductivity, thereby increasing the critical temperature.

Ümmügül Erözbek Güngör

Middle East Technical University, Turkey

Title: Parametrical optimization of inductively coupled RF ion thruster design

Time : 15:05-15:25

Biography:

Ümmügül Erözbek Güngör has been working as a Research Assistant in the Physics Department at Middle East Technical University (METU) since 2012. She has a BS and an MS Degree in Physics and is a Physics Teacher at the METU. She also holds a PhD in Physics. She has recently been working on plasma Spectroscopy, Plasma Diagnostics and Plasma Modeling.

Abstract:

Nowadays, the popularity of the plasma thrusters, which has a simple and compact design, is increasing in-space applications. The inductively coupled radio frequency (RF) ion thrusters (ICP-RITs) are mostly preferred due to supplying high specific impulse and high efficiency. The ICP-RITs are composed of five main parts; discharge vessel, RF coils (RFC), RF generator with its matching network system (RFG), ion optics system (IOS-screen grid, accelerator grid and decelerator grid) and a neutralizer. To understand the physical working principles of these devices, it is necessary to solve the electromagnetic (EM) field equations, which are based on the Maxwell`s equations. Therefore, in this study, we used the COMSOL Multiphysics® software program for the numerical analysis of the ICP-RITs. Firstly, we investigated the locational (along the axial direction of the discharge vessel-at the center and on the upper part that is close to the ion extraction unit) effects of the RF coils on the generated plasma parameters (ne and Te) at 30 mTorr-300 Watt as shown in Figure 2. The coils shown in Figure 1 provide 10 times more ni and 2.6 times more at the screen grid. These parametrical analyses can be clearly observed in the Figure 2-b. For this reason, the following studies were based on this configuration. Then, we tried to understand the effects of the aspect ratio (AR=L-length/D-diameter=2, 3, 4, 5 and 6) and the gas pressure (30-230 mTorr) on the plasma parameters, ion density and electron temperature for the fixed RF power (300 Watt). In Figure 3-a, the density belongs to the ions that are extracted from the screen grid. The location of the screen grid can be seen from the Figure-1. As clearly seen from the Figure 3-a, the ion density increases logarithmically with the gas pressure and the aspect ratio. The reason of this increase due to the pressure is the ideal gas law. From the Figure 3-b, all the electron temperature variations are overlap. However, a closer view to the graph shows that the variations are slightly different from each other with respect to the aspect ratio value. Also, a temperature exponential decrement with the gas pressure is clearly observed from the figüre. Because the number of the Ar gas particle increases with increasing gas pressure. However, at constant RF power, the average electron thermal energy decreases that means the thermal kinetic energy per charge also decreases. In conclusion, the main goal of this work is attracting more ions from the RF ion thruster. To achieve this goal, we will design our thruster according to the dimensions recorded at AR=6 and also we will set the gas pressure at 230 mTorr.

Recent Publications:
1. Dobkevicius M and Feili D (2017) Multiphysics model for radio-frequency gridded ion thruster performance. Journal of Propulsion and Power 33:939–953.
2. Turkoz E and Celik M (2014) 2D Electromagnetic and fluid models for inductively coupled plasma for RF ion thruster performance evaluation. IEEE Transactions on Plasma Science 42:235–40.
3. Chabert P, Monreal J A, Bredin J, Popelier L and Aanesland A (2012) Global model of a gridded-ion thruster powered by a radiofrequency inductive coil. Physics of Plasmas 19:1–8.
4. Browning J, Lee C, Plumlee D, Shawver S, Loo S, et al. (2011) A miniature inductively coupled plasma source for ion thrusters. IEEE Transaction on Plasma Science 39:3187–3195.
5. Goebel D (2008) Analytical discharge model for RF ion thrusters. IEEE Transactions on Plasma Science 36:2111–2121.

Biography:

Mohamed El-Zohry has completed his PhD from Yerevan State University and and is now a Lecturer of Physics at the Physics Department of Sohag University. He has published more than 15 papers in different international reputed journals.

Abstract:

The Brueckner-Hartree-Fock (BHF) approximation for the two-body forces fails to reproduce "correctly" the empirical saturation point of the symmetric nuclear matter (ρo = 0.625 fm-3) for the Argonne V18 potential and (ρo = 0.33 fmt) for the BoonB potential. In the present work one may introduce a Skyrme effective introduction density dependent term in addition to the BHF calculations to obtain the correction parameters for Three-Body Force (TBF). The three-body effects are studied for both asymmetric nuclear matter and pure neutron matter to calculate the nuclear Equation Of State (EOS). The TBF contribution to the EOS of the nuclear matter is repulsive within the BHF framework. The introduction of the TBF shifts and improves the saturation properties of the nuclear matter (ρo = 0.2 fm-3, Eo/A = -15.27 MeV) for the Argonne potential and (ρo = 0.17 fm-3, Eo/A = -17 MeV) for the BonnB potential towards to the empirical saturation point. The incompressibilit at the saturation densities for the two different potentials is studied and it's found 246.97 MeV for the Argonne potential and 216.7 MeV for the BonnB potential comparing with the experimental value for the symmetric nuclear matter have been determined to be 240 ±20 MeV. The pressure as a function of the density in fm-3 for the symmetric nuclear matter is calculated, negative values for the pressure at densities below the saturation density are obtained, the pressure starts to increase as the increasing of the density up to zero value at the saturation density.

Shaidullin R I

Moscow Institute of Physics and Technology, Russia

Title: Thermal limits of fiber lasers power scaling

Time : 16:05-16:25

Biography:

Shaidullin R I has completed his PhD from the Institute of Radio Engineering and Electronics of RAS. He is the Senior Researcher at the Institute of Radio Engineering and Electronics of RAS and a Lecturer in Moscow Institute of Physics and Technology. He has published more than five papers in reputed journals and more than 15 abstracts  at international conferences.

Abstract:

The output radiation power of modern continuous wave single-mode fiber lasers exceeds 10 kW level with radiation intensity in the fiber core more than 108 W/cm2. Some part of optical pump power, inevitably converts into heat due to the fundamental difference between the pump and generation photon energies, leading to a considerable heating of the active fiber core. A high temperature of the fiber detrimentally affects the laser characteristics and leads to thermal degradation of the fiber, especially its protective polymer layer. Fiber laser filamentous structure results in significant nonuniformity of transverse and longitudinal temperature distribution and high temperature gradients inside the fiber. Therefore, traditional thermal measurement methods don’t allow determining distribution of absolute temperature values inside fiber laser. In this study, experimental techniques based on radio-frequency impedance spectroscopy was applied for measurement of active fiber heating. Since dielectric constant of polymer coating of conventional active fibers depends on temperature, then electric impedance of optical fiber is also a function of its temperature. This technique allowed direct measuring of the polymer coating heating, which thermal degradation is one the most limiting factor of fiber laser power scaling. Thermal regime inside entire commercial fiber laser unit was also investigated. Mathematical modeling of thermal processes in fiber laser based on heat conduction equation solution allowed determination of contribution of different mechanisms to the fiber laser heating and temperature distribution inside the fiber laser. All boundary conditions for this modeling were obtained experimentally.

Biography:

Albiomy Abd El-Daiem has his expertise in Nuclear and Particle Physics, especially in Nuclear Emulsion Interactions. His specialization connects between theoretical models and experimental data which allow us to understand the internal structure of the nucleons as well as other particles.

Abstract:

This work studies the correlations between multiplicities of slow particles produced in the interactions of 24Mg with emulsion at 4.5 A GeV/c to extract the information about the mechanism of particle production. The results have been compared with the experimental results obtained by other workers. Also several types of correlations between them have been investigated. The variation of the produced particles with projectile mass number and target size has been studied. Finally, there is no distinct correlation between the shower particle production and the target excitation, but the average value of grey particles decreases with the increase of the number of black particles and vice versa for 28Si with emulsion at 4.5 GeV/c.

Recent Publications:
1. A Abd El Daiem (2015) Interaction of 28Si ions with emulsion nuclei at momentum 4.5 A GeV/c Journal of Nuclear and Particle Physics 5(1):10–14.
2. A Abd El Daiem and A A M Habib (2015) Characteristics of inelastic interactions light nuclei at 4.5 A GeV/c with the nuclei (CNO) and (Ag Br). International Journal of Pure and Applied Physics 11(1):1–8.
3. A Abd El Daiem (2015) Study some features of the total disintegration events of heavy emulsion targets from 28Si at 4.5 A GeV/c. Journal of Nuclear and Particle Physics 5(1):1–9.
4. A Abd El Daiem (2014) Description of high Ns-Multiplicity events produced in relativistic heavy ion collisions At 4.5 A GeV/c. International Journal of Pure and Applied Physics 10(1):63–73.
5. A Abd El-Daiem (2017) The radiological impacts of TE-NORM activity in upper Egypt. International Journal of Research and Reviews in Applied Sciences, IJRRAS 33(1). q

Aleksei Koniashkin

Moscow Institute of Physics and Technology, Russia

Title: Concept of equivalent temperature of laser crystals and glasses

Time : 16:45-17:05

Biography:

Aleksei Konyashkin completed his PhD from Kotelnikov Institute of Radio Engineering and Electronics of RAS. He is the Senior Scientist at the Kotelnikov Institute of Radio Engineering and Electronics of RAS. He has published more than 15 papers in reputed journals.

Abstract:

One of the main factors that characterizes crystal quality, is overheating induced by interaction with laser radiation. Nonuniformity of crystal temperature distribution is a condition by the intensity distribution of propagating laser radiation. In this case, a conventional approach using thermodynamic temperature for the characterization of crystal heating is incorrect. Recently, we have introduced novel notion of equivalent temperature of nonlinear-optical crystals interacting with laser radiation. All nonlinear-optical crystals possess piezoelectric properties. Value of the crystal equivalent temperature is determined directly by measuring a frequency shift of the crystal eigenmodes, which are noncontactly excited by application of the probe radiofrequency electric field. This approach was successfully applied for the investigation of massive lithium triborate (LBO) crystal boules. It is necessary to take into account the presence of the considerable temperature gradient inside the large-size crystals when investigating its interaction with laser radiation. Here, for the determination of the optical absorption coefficient, it is not sufficient to know the equivalent temperature measured using certain resonance of the sample, because an additional information such as the surface temperature is necessary. For this purpose, it is proposed to use the tiny microresonators made of piezoelectric crystals, which resonance frequencies are strongly temperature sensitive. Microresonators should exhibit both high heat conductivity and low optical absorption at involved radiation wavelengths.
When the microresonator is placed onto the crystal boule, its temperature can be identified with the temperature of the corresponding area of the boule surface. During the laser irradiation, the kinetics of both the equivalent volume temperature of the boule and the temperature distribution at its surface were measured. Then the absorption coefficient of the boule was calculated by solving the nonstationary heat conduction equation taking into account the heat transfer change with both environment temperature and the surface temperature of the crystal.