Bulletin of the American Physical Society
59th Annual Meeting of the APS Division of Plasma Physics
Volume 62, Number 12
Monday–Friday, October 23–27, 2017; Milwaukee, Wisconsin
Session YP11: Poster Session IX: Supplemental; PostDeadline Abstracts 
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Room: Exhibit Hall D 

YP11.00001: SUPPLEMENTAL 

YP11.00002: Binary gas mixture in a high speed channel Dr. Sahadev Pradhan The viscous, compressible flow in a 2D wallbounded channel, with bottom wall moving in the positive $x$ direction, simulated using the direct simulation Monte Carlo (DSMC) method, has been used as a test bed for examining different aspects of flow phenomenon and separation performance of a binary gas mixture at Mach number \textit{Ma }$=$\textit{ (U\textunderscore w / }$\backslash $\textit{sqrt(}$\gamma $\textit{ k\textunderscore B T\textunderscore w /m) }in the range\textit{ 0.1 \textless Ma \textless 30}, and Knudsen number \textit{Kn }$=$\textit{ 1/(}$\backslash $\textit{sqrt(2) }$\pi $\textit{ d\textasciicircum 2 n\textunderscore d H)} in the range \textit{0.1 \textless Kn \textless 10}. The generalized analytical model is formulated which includes the fifth order differential equation for the boundary layer at the channel wall in terms of master potential ($\chi )$, which is derived from the equations of motion in a 2D rectangular $(x  y)$ coordinate. The starting point of the analytical model is the NavierStokes, mass, momentum and energy conservation equations in the $(x  y)$ coordinate, where $x$ and $y$ are the streamwise and wallnormal directions, respectively. The linearization approximation is used ((Pradhan {\&} Kumaran\textit{, J. Fluid Mech }2011); (Kumaran {\&} Pradhan, \textit{J. Fluid Mech }2014)), where the equations of motion are truncated at linear order in the velocity and pressure perturbations to the base flow, which is an isothermal compressible Couette flow. Additional assumptions in the analytical model include high aspect ratio \textit{(L \textgreater \textgreater H)}, constant temperature in the base state (isothermal condition), and low Reynolds number (laminar flow). The analytical solutions are compared with direct simulation Monte Carlo (DSMC) simulations and found good agreement (with a difference of less than 10{\%}), provided the boundary conditions are accurately incorporated in the analytical solution. [Preview Abstract] 

YP11.00003: DSMC Simulations of High Mach Number TaylorCouette Flow Dr. Sahadev Pradhan The main focus of this work is to characterise the TaylorCouette flow of an ideal gas between two coaxial cylinders at Mach number \textit{Ma }$=$\textit{ (U\textunderscore w / }$\backslash $\textit{sqrt\textbraceleft kb T\textunderscore w / m\textbraceright )}in the range 0.01 \textless Ma \textless , and Knudsen number \textit{Kn }$=$\textit{ (1 / (}$\backslash $\textit{sqrt\textbraceleft 2\textbraceright }$\backslash $\textit{pi d\textasciicircum 2 n\textunderscore d (r\textunderscore 2  r\textunderscore 1))) }in the range 0.001 \textless Kn \textless , using twodimensional (2D) direct simulation Monte Carlo (DSMC) simulations. Here, \textit{r\textunderscore 1}and \textit{r\textunderscore 2}are the radius of inner and outer cylinder respectively, \textit{U\textunderscore w}is the circumferential wall velocity of the inner cylinder, \textit{T\textunderscore w}is the isothermal wall temperature, \textit{n\textunderscore d}is the number density of the gas molecules, $m$and $d$ are the molecular mass and diameter, and \textit{kb}is the Boltzmann constant. The cylindrical surfaces are specified as being diffusely reflecting with the thermal accommodation coefficient equal to one. In the present analysis of high Mach number compressible TaylorCouette flow using DSMC method, wall slip in the temperature and the velocities are found to be significant. Slip occurs because the temperature/velocity of the molecules incident on the wall could be very different from that of the wall, even though the temperature/velocity of the reflected molecules is equal to that of the wall. Due to the high surface speed of the inner cylinder, significant heating of the gas is taking place. The gas temperature increases until the heat transfer to the surface equals the work done in moving the surface. The highest temperature is obtained near the moving surface of the inner cylinder at a radius of about (1.26 r\textunderscore 1). [Preview Abstract] 

YP11.00004: Observation of plasma microwave emission during the injection of supersonic plasma flows into magnetic arch Mikhail Viktorov, Dmitry Mansfeld, Alexander Vodopyanov, Sergey Golubev Understanding of the energy transfer mechanisms from supersonic plasma flow into the thermal energy of plasma, waves and accelerated particles in the environment of planetary bow shocks and interplanetary shocks have been topical for many decades. Almost all mechanisms of energy dissipation in collisionless shock waves end with microscopic processes involving waveparticle interactions. Excitation of plasma waves in electron cyclotron frequency range plays an important role in the dissipation of bulk flow energy across the Earth bow shock. In the present work, the process of plasma deceleration during the injection of supersonic plasma flow across the magnetic field of an arched configuration is experimentally demonstrated. Pulsed plasma microwave emission in the electron cyclotron frequency range is observed. It is shown that the frequency spectrum of plasma emission is determined by the position of the deceleration region in the magnetic field of the magnetic arc and its bandwidth is defined by the magnetic field inhomogeneity in the deceleration region. The observed emission can be related to the cyclotron mechanism of wave generation by nonequilibrium energetic electrons in the dense plasma, especially excitation of electron Bernstein waves. [Preview Abstract] 

YP11.00005: On the correspondence between classical geometric phase of gyromotion and quantum Berry phase Hongxuan Zhu, Hong Qin We show that the geometric phase of the gyromotion of a classical charged particle in a uniform timedependent magnetic field described by Newton's equation can be derived from a coherent Berry phase for the coherent states of the Schrödinger equation. This correspondence is established by constructing coherent states for a particle using the energy eigenstates on the Landau levels and proving that the coherent states can maintain their status of coherent states during the slow varying of the magnetic field. It is discovered that the orbital Berry phases of the eigenstates interfere coherently to produce an observable effect, which is exactly the geometric phase of the classical gyromotion. The use of the adiabatic theorem is justified. The conclusion also applies to electrons described by the Dirac equation. [1] \\$[1]$ Hongxuan Zhu and Hong Qin {\it On the correspondence between classical geometric phase of gyromotion and quantum Berry phase}, Phys. Plasmas {\bf 24}, 022121 (2017). [Preview Abstract] 

YP11.00006: Some not such wonderful magnetic fusion facts; and their solution Wallace Manheimer The first not such wonderful fusion fact (NSWFF) is that if ITER is successful, it is nowhere near ready to develop into a DEMO. The design Q=10, along with electricity generating efficiency of 1/3 prevents this. Making it smaller and cheaper, increasing the gain by 3 or 4, and the wall loading by an order of magnitude is not a minor detail, it is not at all clear the success with ITER will lead to a similar, pure fusion DEMO. The second NSWFF is that tokamaks are unlikely to improve to the point where they can be effective fusion reactors because their performance is limited by conservative design rules. The third NSWFF is that developing large fusion devices like ITER takes an enormous amount of time and dollars, there are no second chances. The fourth NSWFF is that it is unlikely that alternative confinement configurations will succeed either, at least in this century; they are simply too far behind. There is only a single solution for fusion to become a sustainable, carbon free power source by midcentury or shortly thereafter. This is to develop ITER (assuming it is successful) into a fusion breeder. [Preview Abstract] 

YP11.00007: Abstract Withdrawn


YP11.00008: Sample preheating in magnetic ramp compression experiments on the GEPI high pulsed power driver. Thierry d'Almeida, PierreYves Chanal, JeanLuc Zinszner, Gaetan Daulhac GEPI is a 3 MA, 500 ns, high pulsed power driver operated by the CEA and mainly used for dynamically compressing materials in a quasiisentropic regime at stress levels up to 100 GPa. Usually, materials are loaded starting from ambient temperature conditions, thus, following a single thermodynamic path near an isentrope. Dynamically loading samples from nonambient initial conditions, either in pressure$^{\mathrm{\thinspace }}$or temperature, can significantly improve our ability to obtain direct measurements over specific thermodynamic paths of interest. For instance, rampcompressing multiphase metallic materials from various initial temperatures can help constrain their Equation of State. We have recently equipped the GEPI facility with a preheating device capable of preheating metallic samples up to 1100 K prior to their loading. We present results from preliminary experiments on copper and iron ramp compressed starting from temperatures ranging from 300 K to 900K. [Preview Abstract] 

YP11.00009: Various Forms of Power Radiated via Radiative Damping by Using Higher Order Terms in Super Intense Laser Matter Interaction Rishi Pandit, Edward Ackad, Emmanuel d'Humieres, Yasuhiko Sentoku We had derived the radiation reaction terms including the higher orders and implemented in PICLS codes [R. Pandit and Y. Sentoku, Phys. Plasmas 19, 073304(2012)]. We also derived the power radiated via radiative damping using higher order terms of radiative damping for the first time in various forms, the angular distribution, the spectral distribution or the combined angular and spectral distributions of radiation. These various forms of power radiated in the interaction of extremely intense laser ($> 10^{22} W/cm^{2} $) with dense plasma are studied with a help of a collisional particleincell simulation, PICLS coupled with radiation transport code. It is found that the direction of motion of electron is a strongly preferred direction of emission at high energies. The narrow cone of radiation generated by an energetic electron indicates that only a small part of the trajectory is effective in producing radiation observed in a given direction, which also implies that very high frequencies are emitted. We will discuss the laser intensity and electron energy dependence of the entire spectral and angular distribution of radiation via radiative damping in super intense laser matter interactions. [Preview Abstract] 

YP11.00010: Numerical simulation of exploding pusher targets S. Atzeni, M. J. Rosenberg, M. Gatu Johnson, R. D. Petrasso Exploding pusher targets, i.e. gasfilled large aspectratio glass or plastic shells, driven by a strong lasergenerated shock, are widely used as pulsed sources of neutrons and fast charged particles. Recent experiments on exploding pushers provided evidence for the transition from a purely fluid behavior to a kinetic one [1]. Indeed, fluid models largely overpredict yield and temperature as the Knudsen number Kn (ratio of ion meanfree path to compressed gas radius) is comparable or larger than one. At Kn $=$ 0.3  1, fluid codes reasonably estimate integral quantities as yield and neutronaveraged temperatures, but do not reproduce burn radii, burn profiles and DD/DHe3 yield ratio. This motivated a detailed simulation study of intermediateKn exploding pushers. We will show how simulation results depend on models for laserinteraction, electron conductivity (fluxlimited local vs nonlocal), viscosity (physical vs artificial), and ion mixing. [1] M. J. Rosenberg et al., Phys. Rev. Lett. 112, 014022 (2014); Phys. Plasmas 22, 062702 (2015). [Preview Abstract] 

YP11.00011: Selforganized edge density profile with turbulent pinch Ben Zhu, Manaura Francisquez, Barrett Rogers In many tokamak operations, plasma is only fueled by ionization of neutrals in the periphery which subsequently penetrate inward toward core and form a peaked density profile  a process commonly referred as density pinch. Although the Ware effect, and drift wave/ITG/TEMbased turbulent transport theory are proposed to explain density pinch in the core region ($r/a<0.6$), the density pinch on the edge region remains barely explored to date. We present here an edge density pinch study based on the global 3D twofluid edge turbulence code, GDB. GDB is a fluxdriven electromagnetic model selfconsistently evolving plasma density, temperature as well as the sheared flow profiles in both closedflux surfaces and the SOL. In this study, the effective simulation domain is $0.8 

YP11.00012: Numerical investigation of design and operation parameters on CHI spheromak performance J.B. O'Bryan, C.R. RomeroTalamás, S. Woodruff Nonlinear, numerical computation with the NIMROD code is used to explore magnetic selforganization in spheromaks formed with coaxial helicity injection, particularly with regard to how externally controllable parameters affect the resulting spheromak performance. The overall goal of our study is to inform the design and operational parameters of a future proofofprinciple spheromak experiment. Our calculations start from vacuum magnetic fields and model multiple distinct phases of evolution. Results indicate that modest changes to the design and operation of past experiments, e.g. SSPX [E.B. Hooper et al. PPCF 2012], could have significantly improved the plasmacurrent injector coupling efficiency and performance, particularly with respect to peak temperature and lifetime. While we frequently characterize performance relative to SSPX, our conclusions extrapolate to fundamentally different experimental designs. We also explore adiabatic magnetic compression of spheromaks, which may allow for a smallscale, highperformance and highyield pulsed neutron source. [Preview Abstract] 

YP11.00013: Conservation Laws for Gyrokinetic Equations for Large Perturbations and Flows Andris Dimits Gyrokinetic theory has proved to be very useful for the understanding of magnetized plasmas, both to simplify analytical treatments and as a basis for efficient numerical simulations. Gyrokinetic theories were previously developed [13] in two extended orderings that are applicable to large fluctuations and flows as may arise in the tokamak edge and scrapeoff layer. In the present work, we cast the resulting equations in a fieldtheoretical variational form, and derive, up to second order in the respective orderings, the associated global and local energy and (linear and toroidal) momentum conservation relations that result from Noether's theorem. The consequences of these for the various possible choices of numerical discretization used in gyrokinetic simulations are considered. [1] A.M. Dimits, Phys. Plasmas \textbf{19} 022504 (2012); [2] A.M. Dimits, Phys. Plasmas \textbf{17}, 055901 (2010); [3] A.Y. Sharma and B.F. McMillan, Phys. of Plasmas \textbf{22}, 032510 (2015). [Preview Abstract] 

YP11.00014: Generating uniform, nonequilibrium, mid to highZ plasmas for radiative properties studies at the Omega laser facility G. Elijah Kemp, L.C. Jarrott, E.V. Marley, R.F. Heeter, D.A. Liedahl, C.W. Mauche, P.K. Patel, M.B. Schneider, K. Widmann, M.E. Foord Recent experiments and theoretical work are focused on improving our nonlocal thermodynamic equilibrium (NLTE) atomic models, important for understanding intense laserheated plasma such as those found in inertial confinement fusion (ICF) hohlraums and highenergydensity (HED) experiments. These hot (multikeV), highly ionized plasmas, require complex NLTE atomic physics modeling to predict the radiation emission and transport. A laserheated, buriedlayer target platform on the Omega laser facility is being developed for the purposes of benchmarking our atomic physics models  plasma density and temperature uniformity of the mid to highZ buriedlayer are critical to this work. We describe our radiationhydrodynamic simulations used to understand the spatial and temporal evolution of the density, temperature and xray emission. Comparisons with Omega data along with designs to push the platform to more extreme conditions on the National Ignition Facility will be presented. [Preview Abstract] 

YP11.00015: An Ionization and Equation of State Model for Dense, Plasma Mixtures Liam Stanton, Robert Argus, Olga Dorabiala, Zander Kelley, Brandon Sripimonwan, Christian Scullard, Frank Graziani, Yannan Shen, Michael Murillo Almost all high energydensity physics experiments involve a multitude of species, which introduces nontrivial challenges to the models for both theoretical and practical reasons. To make matters worse, the ionic species will be composed of multiple ionization states themselves. The theoretical connection to the singlespecies properties, such as the transport coefficients or equations of state, is rarely as straightforward as a simple superposition. Additionally, our knowledge of such mixtures must span orders of magnitude in temperature and density, and impurities from higherZ elements can fundamentally change the physical properties of the plasma as well. Here, we present a new model that can accurately and efficiently predict ionization, thermodynamic and correlational properties of dense plasma mixtures over a wide range parameter. This model is not only applicable to mixtures of an arbitrary number of ionic components, but it resolves properties of individual ionization states as well. [Preview Abstract] 

YP11.00016: Particleincell simulations of hot electron generation with high intensity IR laser in shock ignition regime Jun Li, Shu Zhang, Eli Borwick, Chuang Ren, Farhat Beg, Mingsheng Wei Experiments [1] conducted on OMEGA EP laser facility with highintensity, multikJ IR laser (5\texttimes 10$^{\mathrm{15}}$W/cm$^{\mathrm{2}}$, 2.5kJ, 100 ps) have shown strongly directional hot electrons with moderate temperature (90 keV), which is favorable for electron assisted shock ignition. We performed 2dimensional particleincell (PIC) simulations using the OSIRIS code to study the hot electron generation by laser plasma instabilities(LPI) in the experiments. We aimed at investigating the hot electron energy fraction, temperature and angular distribution and the corresponding LPIs contribution. The simulation results show SRS is the dominant LPI. The hot electrons generated by SRS are directional with a half angle of 23 degree, and the temperature of the hot electrons is 81 keV, which agrees very well with the experiments. More details of the simulation results will be presented in the meeting. The research used resources of the National Energy Research Scientific Computing Center. [1] M.S. Wei et al., Bulletin of the APS, 61 (2016): BAPS.2016.DPP.JO8.12 [Preview Abstract] 

YP11.00017: Particle transport in the vicinity of divertor separatrix Y. Nishimura, J.C. Lyu Guiding center orbit following code in a tokamak edge geometry is developed which connects straight field line coordinate system (away from the separatrix) and Cartesian coordinate system (in the vicinity of the separatrix) smoothly in the equation of motion.\footnote{Coordinate transformations $x=x ( \psi , \theta)$, $ y = y (\psi , \theta)$, and $\psi = \psi (x,y)$, $ \theta = \theta (x,y)$ are obtained by solving magnetic field line equation.} In the presence of magnetic stochasticity, \footnote{H.Takahashi, E.D.Fredrickson {\it et al.}, Nucl. Fusion {\bf 44}, 1075 (2004).} \footnote{T.E.Evans, R.A.Moyer {\it et al.}, Nature Physics {\bf 2}, 419 (2006).} charged particles in the closed magnetic field line region can be transported to the open field line region and then hit the divertor plates within several toroidal transits. Our preliminary studies suggest finite heat load both on the inner and outer divertor plates. Energy spectrum of particles reaching the plates (which differs from that of the bulk plasma) as function of imposed magnetic stochasticity, is analyzed. This work is supported by Taiwan MOST 1042112M006019. [Preview Abstract] 

YP11.00018: Foamlined hohlraums at the National Ignition Facility Cliff Thomas Indirect drive inertial confinement fusion (ICF) is made difficult by hohlraum wall motion, laser backscatter, xray preheat, highenergy electrons, and specular reflection of the incident laser (i.e. glint). To mitigate, we line the hohlraum with a lowdensity metal foam, or tamper, whose properties can be readily engineered (opacity, density, laser absorption, ionacoustic damping, etc.). We motivate the use of lowdensity foams for these purposes, discuss their development, and present initial findings. Importantly, we demonstrate that we can fabricate a 200500 um thick liner at densities of 10100 mg/cm3 that could extend the capabilities of existing physics platforms. The goal of this work is to increase energy coupled to the capsule, and maximize the yield available to science missions at the National Ignition Facility. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DEAC5207NA27344. [Preview Abstract] 

YP11.00019: Hybrid laserplasma wakefield acceleration Bernhard Hidding, Thomas Heinemann, Paul Scherkl, Daniel Ullmann, Andrew Beaton Laser wakefield accelerators (LWFA) can produce electron bunches with characteristics which suggest they are highly suitable to be used as drivers for electronbeam driven plasma wakefield accelerators (PWFA) [1]. The presentation will report on recent experimental results and conceptual advanced which substantiate this idea. It looks as if hybrid LWFAPWFA systems are highly promising systems to harness specific advantages of PWFA (no dephasing, long acceleration distances, wide potential for ionization injection schemes) realized these in truly compact systems. [1] B. Hidding et al., Monoenergetic energy doubling in a hybrid laserplasma wakefield accelerator, Physical Review Letters 104, 195002, 2010 [2] S. Kuschel et al., Demonstration of passive plasma lensing of a laser wakefield accelerated electron bunch, Phys. Rev. Accel. Beams 19, 071301 (2016) [3] O. Karger et al., to be submitted [Preview Abstract] 

YP11.00020: Multigrid treatment of implicit continuum diffusion Manaure Francisquez, Ben Zhu, Barrett Rogers Implicit treatment of diffusive terms of various differential orders common in continuum mechanics modeling, such as computational fluid dynamics, is investigated with spectral and multigrid algorithms in nonperiodic 2D domains. In doubly periodic time dependent problems these terms can be efficiently and implicitly handled by spectral methods, but in nonperiodic systems solved with distributed memory parallel computing and 2D domain decomposition, this efficiency is lost for large numbers of processors. We built and present here a multigrid algorithm for these types of problems which outperforms a spectral solution that employs the highly optimized FFTW library. This multigrid algorithm is not only suitable for high performance computing but may also be able to efficiently treat implicit diffusion of arbitrary order by introducing auxiliary equations of lower order. We test these solvers for fourth and sixth order diffusion with idealized harmonic test functions as well as a turbulent 2D magnetohydrodynamic simulation. It is also shown that an anisotropic operator without crossterms can improve model accuracy and speed, and we examine the impact that the various diffusion operators have on the energy, the enstrophy, and the qualitative aspect of a simulation. [Preview Abstract] 

YP11.00021: Creating laboratory gammaray bursts with 10\textasciicircum 21 W.cm\textasciicircum 2 laser Edison Liang, Willie Lo, Hannah Hasson, Todd Ditmire, Gillis Dyer, Ilija Marchenka, Fabio Fasanelli, Michael Donovan Using the Texas Petawatt Laser (TPW) to irradiate thick Au and Pt targets at 10\textasciicircum 21 W.cm\textasciicircum 2 and above, we have created highdensity, shortpulse (100 fs) electron, positron and gammaray jets with insitu physical parameters comparable to those found in cosmic gammaray bursts. For cmsized targets, we discover that the hot electron emission is suppressed near the target normal direction, while the positron emission is not. This leads to the creation of angleselected positrondominated jets, which have many applications. We will present the results from both experiments and computer simulations, and discuss potential future applications. [Preview Abstract] 

YP11.00022: Status of parallel Pythonbased implementation of UEDGE M.V. Umansky, A.Y. Pankin, T.D. Rognlien, A.M. Dimits, A. Friedman, I. Joseph The tokamak edge transport code UEDGE [1] has long used the codedevelopment and runtime framework Basis [2]. However, with the support for Basis expected to terminate in the coming years, and with the advent of the modern numerical language Python, it has become desirable to move UEDGE to Python, to ensure its longterm viability.~Our new Pythonbased UEDGE implementation takes advantage of the portable build system developed for FACETS [3]. The new implementation gives access to Python's graphical libraries and numerical packages for pre and postprocessing, and support of HDF5 simplifies exchanging data. The older serial version of UEDGE has used for timestepping the NewtonKrylov solver NKSOL. The renovated implementation uses backward Euler discretization with nonlinear solvers from PETSc [4], which has the promise to significantly improve the UEDGE parallel performance [5]. We will report on assessment of some of the extended UEDGE capabilities emerging in the new implementation, and will discuss the future directions. [1] Rognlien et al., J. Nuc. Mat. 196, 347123 (1992); [2] Dubois. et al. LLNL Report UCRLMA118543PT2 (1994); [3] Cary et al., J. Physics: Conference Series180 (2009) 012056 (2009); [4] Balay et al., ANL Technical Report ANL95/11 (2011); [5] McCourt et al., Comp. Science {\&} Discovery 5 014012 (2012). [Preview Abstract] 

YP11.00023: POSTDEADLINE 

YP11.00024: An Extension of the Miller Equilibrium Model into the XPoint Region M.D. Hill, R.W. King, W.M. Stacey The Miller equilibrium model [1] has been extended to better model the flux surfaces in the outer region of the plasma and scrapeoff layer, including the poloidally nonuniform flux surface expansion that occurs in the Xpoint region(s) of diverted tokamaks. Equations for elongation and triangularity are modified to include a poloidally varying component and gradr, which is used in the calculation of the poloidal magnetic field, is rederived. Initial results suggest that strong quantitative agreement with experimental flux surface reconstructions and strong qualitative agreement with poloidal magnetic fields can be obtained using this model. Applications [2] are discussed. A major new application is the automatic generation of the computation mesh in the plasma edge, scrapeoff layer, plenum and divertor regions for use in the GTNEUT [3] neutral particle transport code, enabling this powerful analysis code to be routinely run in experimental analyses. 1) Phys. Plasmas 5 (1998) 973978; 2) Phys. Plasmas 15 (2008) 122505; 3) Comp. Phys. Comm. 161 (2004): 3664. Work supported by US DOE under DEFC0204ER54698. [Preview Abstract] 

YP11.00025: Blobs and drift wave dynamics Yanzeng Zhang, Sergei Krasheninnikov The modified HasegawaMima equation retaining all nonlinearities is investigated from the point of view of the formation of blobs. The linear analysis shows that the amplitude of drift wave packet propagating in the direction of decreasing background plasma density increases and eventually saturates due to nonlinear effects. Nonlinear modification of time averaged plasma density profile results in the formation of large amplitude modes locked in xdirection but still propagating in ydirection, which resembles experimentally observed chain of blobs propagating in poloidal direction. Such specific density profiles, causing the locking of drift waves can form naturally at the edge of tokamak due to neutral ionization source. As a result, locked modes can grow \textit{in situe} due to plasma instabilities, e.g. caused by finite resistivity. Also modulation instability (in poloidal direction) of locked modes can result in a blob like burst of plasma density. [Preview Abstract] 

YP11.00026: Micro hollow cathode discharge jets utilizing solid fuel Dejan Nikic Micro hollow cathode discharge devices with a solid fuel layer embedded between the electrodes have demonstrated an enhanced jetting process. Outlined are series of experiments in various pressure and gas conditions as well as vacuum. Examples of use of these devices in series and parallel configurations are presented. Evidence of utilization of solid fuel is obtained through optical spectroscopy and analysis of remaining fuel layer. [Preview Abstract] 

YP11.00027: Stability and structure of fields in a flow with a hydrodynamic discontinuity Daniil Ilyin, Yasuhide Fukumoto, William Goddard, Snezhana Abarzhi We consider from a far field the evolution of a hydrodynamic discontinuity separating incompressible ideal fluids of different densities, with mass flow across this interface. By solving the boundary value problem and finding fundamental solutions of linearized dynamics, we directly link interface stability to structure of the flow fields. We find that the classic Landau system of equations for the LandauDarrieus instability has a degenerate and singular character. Eliminating this degeneracy leads to appearance of a neutrally stable solution whose vortical field can seed the instability. We further find that the interface is stable if the flux of energy fluctuations produced by the perturbed interface is small compared to the flux of specific kinetic energy across the planar interface. The interface is unstable if the energy fluctuations flux is large compared to the kinetic energy flux. Landau’s solution is consistent with the latter case. Keywords: hydrodynamic instabilities, interfacial dynamics, mixing [Preview Abstract] 

YP11.00028: Maximum initial growthrate of strongshockdriven RichtmyerMeshkov instability Snezhana I. Abarzhi, Aklant K. Bhowmich, Zachary R. Dell, Arun Pandian, Milos Stanic, Robert F. Stellingwerf, Nora C. Swisher We focus on classical problem of dependence on the initial conditions of the initial growthrate of strong shocks driven RichtmyerMeshkov instability (RMI) by developing a novel empirical model and by employing rigorous theories and Smoothed Particle Hydrodynamics (SPH) simulations to describe the simulations data with statistical confidence in a broad parameter regime. For given values of the shock strength, fluids’ density ratio, and wavelength of the initial perturbation of the fluid interface, we find the maximum value of RMI initial growthrate, the corresponding amplitude scale of the initial perturbation, and the maximum fraction of interfacial energy. This amplitude scale is independent of the shock strength and density ratio, and is characteristic quantity of RMI dynamics. We discover the exponential decay of the ratio of the initial and linear growthrates of RMI with the initial perturbation amplitude that excellently agrees with available data. [Preview Abstract] 

YP11.00029: Stability and structure of fields of a flow with a hydrodynamic discontinuity DV Ilyin, WA Goddard III, Y Fukumoto, SI Abarzhi We consider from a far field the evolution of a hydrodynamic discontinuity separating incompressible ideal fluids of different densities, with mass flow across this interface. By solving the boundary value problem and finding fundamental solutions of linearized dynamics, we directly link interface stability to structure of the flow fields. We find that classic Landau’s system of equations for the LandauDarrieus instability has a degenerate and singular character. Eliminating this degeneracy leads to appearance of a neutrally stable solution whose vortical field can seed the instability. We further find that the interface is stable if the flux of energy fluctuations produced by the perturbed interface is small compared to the flux of kinetic energy across the planar interface. The interface is unstable otherwise. Landau’s solution is consistent with the latter case. [Preview Abstract] 

YP11.00030: Temperature Measurements of HighZ Plasma Exiting the Laser Entrance Hole of Ignition Scale Depleted Uranium Hohlraums Nicholas Parrilla, Joe Ralph, Ben Bachmann, Clement Goyon, Eduard Dewald The temperature profile from the Laser Entrance Hole to 3.5 mm from the exit point was measured for plasma with high atomic number (highZ) of Depleted Uranium ignition scale hohlraums. Each hohlraum was filled with 0.6 mg/cc He as part of the high foot CH campaign. Temperature of the flowing plasma is measured by fitting the velocity distribution to a Maxwellian and considering the Planckian spectral distributions with and without a 42 um Ge filter. The two spectra are then compared to determine the temperature of the highZ plasma. [Preview Abstract] 

YP11.00031: Experimental evaluation of opacity in the deep solar interior using the concept of ``microscopic equivalence.'' Yair Kurzweil, Giora Hazak, James Bailey, Taisuke Nagayama A problem for stellar astrophysics is that existing opacity models have been called into question both by experiments [1] and by solar model comparisons with helioseismology, but an alternative opacity model does not yet exist. Importantly, the experiments measured opacity only for iron, at 182 eV  195 eV temperatures (T$_{\mathrm{e}})$ comparable to the value at \textasciitilde 0.7. Experimental validation of opacity models at higher T$_{\mathrm{e}}$ and density (n$_{\mathrm{e}})$ are required to understand the entire Sun. Unfortunately, controlled transmission measurements at the required conditions are extremely difficult to achieve at lab. We propose to help resolve this dilemma using experiments at achieved conditions combined with the ``microscopic equivalence'' principle. Thus, using this principle, we can use a loweratomicnumber surrogate element to test opacity model physics important for iron at higher T$_{\mathrm{e}}$ and n$_{\mathrm{e}}$ than can be reached in present experiments. Theoretical modeling to evaluate this idea, using the CRSTA[2,3]/PRCRSTA [4] models will be discussed. [1] J. E. Bailey \textit{et al}, \textit{Nature} \textbf{517}, 56 (2015). [2] G. Hazak and Y. Kurzweil, High Energy Density Phys., 8, 290 (2012). [3] Y. Kurzweil and G. Hazak, High Energy Density Phys. 9, 548 (2013). [4] Y. Kurzweil and G. Hazak, Phys. Rev. E 94 053210 (2016). [Preview Abstract] 

YP11.00032: Weibel instability in relativistic electron positron plasma. Zahida Ehsan, Nodar Tsintsadze, Peter Yoon We consider a situation in when the interaction of relativistically intense EM waves with an isotropic electron positron?~plasma takes place, i.e., we consider short pulse lasers with intensity up to 10$^{\mathrm{21}}$ W/cm$^{\mathrm{2}}$, in which the photon density is of the order of 10$^{\mathrm{30}}$cm$^{\mathrm{3}}$ and the strength of electric field E $=$ 10$^{\mathrm{9}}$ statvolt/cm. Such a situation is possible in astrophysical and laboratory plasmas which are subject to intense laser radiation, thus leading to nonthermal equilibrium field radiations. Such interaction of the superstrong laser radiation with an isotropic pair plasma leads to the generation of low frequency electromagnetic EM waves and in particular a quasistationary magnetic field. When the relativistic circularly polarized transverse EM wave propagates along zaxis, it creates a ponderomotive force, which affects the motion of particles along the direction of its propagation. On the other hand, motion of the particles across the direction of propagation is defined by the ponderomotive potential. Moreover dispersion relation for the transverse EM wave using a special distribution function, which has an anisotropic form, is derived and is subsequently investigated for a number of special cases. In general, it is shown that the growth rate of the EM wave strongly depends upon its intensity. [Preview Abstract] 

YP11.00033: A new mode and Cherenkov instability in pair plasma. Zahida Ehsan, Nodar Tsintsadze, Hassan Shah, Raoul Trines Positive and negative ions forming the socalled pair plasma differing in sign of their charge but asymmetric in mass and temperature support a new acousticlike mode. The condition for the excitation of ion sound wave through electron beam induced Cherenkov instability is also investigated. This beam can generate a perturbation in the pair ion plasmas in the presence of electrons when there is number density, temperature, and mass difference in the two species of ions. Basic emphasis is on the focusing of ion sound waves, and we show how, in the area of localization of wave energy, the density of pair particles increases while electrons are pushed away from that region. Further, this localization of wave is dependent on the shape of the pulse. Considering the example of pancake and bullet shaped pulses, we find that only the former leads to compression of pair ions in the supersonic regime of the focusing region. Here, possible existence of regions where pure pair particles can exist may also be speculated which is not only useful from academic point of view but also to mimic the situation of plasma (electron positron asymmetric and symmetric) observed [Preview Abstract] 

YP11.00034: Symmetry and Asymmetry Florentin Smarandache In some examples, the Special Theory of Relativity considers a symmetric time dilation of two inertial reference frames. But in other examples, such as in the GPS position system where the satellite clocks are slowed because of the satellite velocity, it considers an asymmetric time dilation of two inertial reference frames. As in the cause of the Twin Paradox, the time dilation was simply\textellipsis abandoned! Again an autocontradiction. [Preview Abstract] 

YP11.00035: Unmatter Plasma revisited Florentin Smarandache Unmmatter Plasma is a novel form of plasma, exclusively made of matter and its antimatter counterpart. The electronpositron beam plasma was generated in the laboratory in the beginning of 2015. This experimental fact shows that unmatter, a new form of matter that is formed by matter and antimatter bind together (mathematically predicted since 2004) really exists. That is the electronpositron plasma experiment of 2015 is the experimentum crucis verifying the mathematically predicted unmatter. Unmatter is formed by combinations of matter and antimatter that bind together, or by longrange mixture of matter and antimatter forming a weaklycoupled phase. Binding and bound state means that the interaction is sufficiently strong to tie together the particles of a system, therefore hindering them from becoming free. For example, a usual liquid is a bound state of molecules, while a gas is an unbounded where the molecules can move freely in successive collisions. [Preview Abstract] 

YP11.00036: Gyrokinetic Magnetohydrodynamics and the Associated Equilibrium W. W. Lee, S. R. Hudson, C. H. Ma A proposed scheme for the calculations of gyrokinetic MHD and its associated equilibrium is discussed related a recent paper on the subject [1]. The scheme is based on the timedependent gyrokinetic vorticity equation and parallel Ohm's law, as well as the associated gyrokinetic Ampere's law. This set of equations, in terms of the electrostatic potential, $\phi$, and the vector potential, ${\bf A}$, supports both spatially varying perpendicular and parallel pressure gradients and their associated currents. The MHD equilibrium can be reached when $\phi \rightarrow 0$ and {\bf A} becomes constant in time, which, in turn, gives $\nabla \cdot ({\bf J}_\parallel + {\bf J}_\perp) = 0$ and the associated magnetic islands. Examples in simple cylindrical geometry will be given. [1] W. W. Lee,"Magnetohydrodynamics for collisionless plasmas from the gyrokinetic perspective," Phys. Plasmas {\bf 23}, 070705 (2016). [Preview Abstract] 

YP11.00037: A new linear plasma device for various edge plasma studies at SWIP Min Xu, Pengfei Zheng, George Tynan, Tong Che, Zhanhui Wang, Dong Guo, Ran Wei To facilitate the plasmamaterial interactions (PMI) studies, Southwestern Institute of Physics (SWIP) has constructed a linear plasma device. It is comprised of a source chamber ($\Phi $ 0.4 m), a target chamber ($\Phi $ 0.9 m), 15 magnets with different sizes, and power supplies with the total power of a few hundred kilowatts, etc. A maximum magnetic field of 0.3 Tesla along the axial direction can be produced. The current of each of the 15 magnets can be independently controlled. More than 60 ports are available for diagnostics, with the sizes vary from $\Phi $ 50 mm to $\Phi $ 150 mm. Rectangular ports of 190 mm×270 mm are also available. 12 ports looking at the sample holder are specially designed for ion beam injection, of which the axes are 25° to the chamber axis. The device is equipped with a LaB6 hot cathode plasma source, which is able to generate steadystate H/D/He plasmas with a diameter of \textasciitilde $\Phi $ 100 mm, density of \textasciitilde 1x10\textasciicircum 19/m\textasciicircum 3, and a particle flux of 10\textasciicircum 22\textasciitilde 10\textasciicircum 23 n/m\textasciicircum 2.s. The electron temperature is usually \textasciitilde a few eV. Further, a Helicon RF plasma source is also planned for plasma transport studies. [Preview Abstract] 

YP11.00038: Divertor detachment and power dissipation by Neon impurity gas seeding Dezhen Wang, Daoyuan Liu, Chaofeng Sang, Liang Wang ScrapeOff Layer Plasma Simulation (SOLPS) code package, has been applied to study the mechanism of neon gas seeding induced radiation power dissipation. Impurity seeding is a conventional method to achieve divertor detachment for the tokamak devices with metallic plasma facing materials (PFMs). Neon (Ne) is one of the typical seeding gases. It is known that the impurities can increase the power radiation significantly; however, the role of different charge state at different locations is still unclear. By comparing distributions of the line radiation losses and the density of different charge states of neon, it is found that the power radiation is not only decided by the impurities density, e.g. the radiation loss is dominated by Ne5$+$, however, Ne8$+$ has the highest peak density, but also decided by the impurity distributions. The main reason is that power radiation is also a function of electron temperature. In the tokamak, different locations have different Te, therefore, it can influence the power radiation rates. By doing a large level of power scan, the power radiation by Ne is evaluated, which can help to understand the impurityinduced detachment for the future reactor. [Preview Abstract] 

YP11.00039: Solving freeplasmaboundary problems with the SIESTA MHD code R. Sanchez, H. PerazaRodriguez, J.M ReynoldsBarredo, V. Tribaldos, J. Geiger, S.P. Hirshman, M. Cianciosa SIESTA [1] is a recently developed MHD equilibrium code designed to perform fast and accurate calculations of ideal MHD equilibria for 3D magnetic configurations. It is an iterative code that uses the solution obtained by the VMEC code [2] to provide a background coordinate system and an initial guess of the solution. The final solution that SIESTA finds can exhibit magnetic islands and stochastic regions. In its original implementation, SIESTA addressed only fixedboundary problems. This fixed boundary condition somewhat restricts its possible applications. In this contribution we describe a recent extension of SIESTA [3] that enables it to address freeplasmaboundary situations, opening up the possibility of investigating problems with SIESTA in which the plasma boundary is perturbed either externally or internally. As an illustration, the extended version of SIESTA is applied to a configuration of the W7X stellarator. [1] S.P. Hirshman, R. Sanchez and C.R. Cook, Phys. Plasmas 18 (2011) 062504 [2] S.P. Hirshman and JC Whitson, Phys. Fluids 26 (1983) 3553; S.P. Hirshman and W.I. Van Rij, Comput. Phys. Comm. 43 (1986) 143 [3] H. PerazaRodriguez, J.M. ReynoldsBarredo, R. Sanchez, V. Tribaldos, J. Geiger, S.P. Hirshman and M. Cianciosa. Phys. Plasmas 24, 082516 (2017) [Preview Abstract] 

YP11.00040: Global Surrogates for the Upshift of the Critical Threshold in the Gradient for ITG Driven Turbulence Craig Michoski, Salomon Janhunen, Danial Faghihi, Varis Carey, Robert Moser The suppression of microturbulence and ultimately the inhibition of largescale instabilities observed in tokamak plasmas is partially characterized by the onset of a global stationary state. This stationary attractor corresponds experimentally to a state of ``marginal stability'' in the plasma. The critical threshold that characterizes the onset in the nonlinear regime is observed both experimentally and numerically to exhibit an upshift relative to the linear theory. That is, the onset in the stationary state is upshifted from those predicted by the linear theory as a function of the ion temperature gradient $R_0/L_T$. Because the transition to this state with enhanced transport and therefore reduced confinement times is inaccessible to the linear theory, strategies for developing nonlinear reduced physics models to predict the upshift have been ongoing. As a complement to these effort, the principle aim of this work is to establish lowfidelity surrogate models that can be used to predict instability driven loss of confinement using training data from highfidelity models. [Preview Abstract] 

YP11.00041: Stochastic acceleration of electrons from multiple uncorrelated plasma waves. David Gee, Pierre Michel, Jonathan Wurtele Onedimensional theory puts a strict limit on the maximum energy attainable by an electron trapped and accelerated by an electron plasma wave (EPW). However, experimental measurements of hot electron distributions accelerated by stimulated Raman scattering (SRS) in ICF experiments typically show a thermal distribution with temperatures of the order of the kinetic energy of the resonant EPW's (Thot \textasciitilde mvp\textasciicircum 2 , where vp is the phase velocity of the EPW's driven by SRS) and no clear cutoff at high energies. In this project, we are investigating conditions under which electrons can be stochastically accelerated by multiple uncorrelated EPW's, such as those generated by incoherent laser speckles in large laser spots like the ones used on NIF (\textasciitilde mmsize), and reproduce distributions similar to those observed in experiments. [Preview Abstract] 

YP11.00042: Surface Modification of Nonwoven fabrics by Atmospheric Brush Plasma Lutfi Oksuz, Emre Uygun, Ferhat Bozduman, Gozde Yurdabak Karaca, Orkun Nuri Asan, Aysegul Uygun Oksuz Polypropylene nonwoven fabrics (PPNF) are used in disposable absorbent articles, such as diapers, feminine care products, wipes. PPNF need to be wettable by water or aqueousbased liquid. Plasma surface treatment/modification has turned out to be a wellaccepted method since it offers superior surface property enhancement than other chemical methods. The cold plasma brush can most efficiently use the discharge power as well as the plasma gas for material and surface treatment. The very low power consumption of such an atmospheric argon plasma brush provides many unique advantages in practical application. The purpose of this study was to reveal the effectiveness of nonthermal atmospheric plasma brush in surface wettability and modification of two different nonwoven surfaces. [Preview Abstract] 

YP11.00043: Atmospheric Plasma Blade for Surgical Purposes Lutfi Oksuz, Gozde Yurdabak Karaca, Emir Özkaptan, Emre Uygun, Aysegul Uygun Oksuz Atmospheric plasma cut is a process at the minimum level due to the ions, radicals and free electrons generated by the active electrode and target tissue. Atmospheric plasma cutting devices provide significant advantages as a noncontact electrocautery system that can operate in isotonic environment. During operations where plasma cutting is applied, bleeding is controlled and the side effects that would create the isotonic environment are eliminated. In this study in vivo and in vitro studies will be carried out by producing and optimizing the atmospheric plasma blade. Once the optimum parameters of the instrument are determined, in vivo studies will be performed and the pathology results will be evaluated. [Preview Abstract] 

YP11.00044: Electronimpact excitation and recombination of molecular cations in edge fusion plasma: application to H2+and BeD+ Nicolina Pop, Felix Iacob, Zsolt Mezei, Ousmanou Motapon, Sebastien Niyonzima, Ioan Schneider Dissociative recombination, rovibrational excitation and dissociative excitation of molecular cations with electrons are major elementary process in the kinetics and in the energy balance of astrophysicallyrelevant ionized media (supernovae, interstellar molecular clouds, planetary ionospheres, early Universe), in edge fusion and in many other cold media of technological interest. For the fusion plasma edge, extensive cross sections and rate coefficients have been produced for reactions induced on HD+, H2+ and BeD+ using the Multichannel Quantum Defect Theory (MQDT). Our calculations resulted in good agreement with the CRYRING (Stockholm) and TSR (Heidelberg) magnetic storage ring results, and our approach is permanently improved in order to face the new generation of electrostatic storage rings, as CSR (Heidelberg) and DESIREE (Stockholm). [Preview Abstract] 

YP11.00045: Analytical formulation for potential energy surfaces in molecular collision dynamics of cold plasma Felix Iacob, Nicolina Pop We consider the characteristic discharge chemistry processes in cold plasma, which are mainly driven by free electrons, but also by ionmolecule reactions. In order to obtain a better description of the collision between two molecules, a form for the molecular interaction potential should be assumed. Determining theoretically the rate coefficients, first one has to focus on electronic calculations of potential energy surfaces (PES), in BO approximation, further used to study the motion of the nuclei (collision dynamics). Currently used are abinitio models, in this work an analytical expression of potential energy surface is derived and used to describe the molecular dynamics in cold plasmas. A specially attention was given to the exotic cases where the present data fully support a model that assumes potential barriers or bottle necks. Some dissociative recombination cross section where calculated using this new analytical form in the case of electron reacting with HD+. Also the MaxwellBoltzmann rates have been calculated being of particular interest to the plasma research. The result are compared with literature. Low temperature experiments have shown that there can be significant deviations from such simple models. [Preview Abstract] 

YP11.00046: Simulations of collisionless counterpropagating plasma flows in support of twowire implosion experiments James Caplinger, Vladimir Sotnikov, Andrew Hamilton One of the simplest configurations leading to colliding plasma flows is created by driving strong currents through a pair of parallel wires. The azimuthal magnetic fields generated around each wire, and the Ohmic current dissipation and heating occurring upon wire evaporation, launches powerful radial outflows of magnetized plasmas. Upon colliding they form a flow pattern suggestive of magnetic field reconnection, and the development of various plasma instabilities. In the current effort, we analyzed collision of two hightemperature precursor light ion plasma flows via PIC (ParticleInCell) simulations using LSP. The aim is to demonstrate the appearance of an electric field parallel to the direction of a plasma flow. This field appears in colliding plasma flows due to the charge separation and is associated with the Buneman instability. It is responsible for the creation of ExB drift of electrons. Next, an interaction between drifting electrons and unmagnetized ions, moving parallel to them, lead to excitation of a modified Buneman instability in the frequency range close to the LowerHybrid frequency. Simulation results will allow us to identify the characteristics of nonlinear density fluctuations that appear in the process of such an interaction. [Preview Abstract] 

YP11.00047: Nonlinear Interaction of Naturally and Artificially Excited VLF and ELF Waves in the Ionosphere Vladimir Sotnikov, James Caplinger, Tony Kim, Euvgeny Mishin We report on analysis of nonlinear parametric coupling between quasielectrostatic whistler waves (also known as Lower Oblique Resonance (LOR) waves) and of Extremely Low Frequency (ELF) fast magnetosonic waves to generate electromagnetic whistler waves. Natural and artificial VLF and ELF sources are analyzed. In the case of naturally excited VLF/ELF waves we show that nonlinear parametric coupling between the LOR and ELF waves suffices to explain the observed electromagnetic whistler waves in the plasmasphere boundary layer. In the case of artificial sources such as a loop antenna a great deal of the source power is radiated not as an electromagnetic whistler wave, but as a quasielectrostatic LOR mode. Only a small percentage of the power is radiated as the electromagnetic whistler wave. We present new results on parametric interaction of LOR waves with ELF waves to demonstrate the possibility to overcome this difficulty. It will be shown that interaction of LOR waves gives rise to excitation of electromagnetic whistler waves. Additionally, particleincell (PIC) simulations, which demonstrate the excitation and spatial structure of VLF waves excited by conventional and parametric sources will be presented. [Preview Abstract] 

YP11.00048: Investigations of spontaneous arc extinction in CsBa plasma of highlyefficient switching converters. Aleksandr Mustafaev, Vladimir Soukhomlinov, Artiom Grabovskiy, Evgenia Shtoda This talk deals with the results of the research into plasma's electro kinetic parameters of Knudsen CsBa highcurrent diode and triode switching converters. The investigations of the spontaneous arc extinction in the devices with a finemesh grid, operating in the collisionless mode, have been carried out. In order to study the mechanism of the arc extinction, the time dependencies of the luminosity of a series of CsI, BaII and BaI lines were obtained. The use of CsBa mixture, where cesium is a plasmaforming component, allowed to obtain emission currents from the cathode up to 100 A/cm$^{\mathrm{2}}$ in Cspressure range 10$^{\mathrm{3}}$10$^{\mathrm{2}}$ Torr and, thus, easily attain the electric power density of 5~kW/cm$^{\mathrm{2\thinspace }}$and the efficiency more than 95{\%}$^{\mathrm{1,2}}$. It has been established, that the arc extinction in the triode, having the finemesh, highlytransparent grid, is due to the high degree of atom ionization and to the escape of atoms from the spacing, while the large duration of the current pulse is determined by atom desorption from the electrodes. 1. A. Mustafaev, V. Soukhomlinov, et. all. 44th ICOPS2017. WE Posters7. (AtlanticCity, New Jersey, USA). 2. A. Mustafaev, V. Soukhomlinov, O. Murillo. FiftyEighth Annual Meeting of the APS Division of Plasma Physics, 2016, P. JP10.00161. (San Jose, California, USA). [Preview Abstract] 

YP11.00049: Ultracompact photoionization analyzers. Ecological monitoring application at hazardous production facilities. Alexander Mustafaev, Iuliia Rastvorova, Fatima Arslanova It is generally recognized that careful implementation of ecological monitoring should be provided at hazardous production facilities continuously to protect the surrounding environment as well as health and safety of employees. However, the existing devices may not be able to control the environmental situation uninterruptedly due to their technical characteristics or measurement methods. Developed by The Mining University Plasma Research Group ultracompact photoionization analyzer is proposed as innovative equipment which creates the basis for a new measuring approach. The general operating principle is based on the patented method of stabilization of electric parameters  CES (Collisional Electron Spectroscopy). During the operation at the atmospheric pressure, the vacuum ultraviolet (VUV) photoionization sensor measures the energy of electrons produced by means of ionization with the resonance photons whose wavelength is situated in the VUV. A special software tool was developed to obtain the secondorder derivative of the IU characteristics, taken by the VUV sensor, to construct the characteristic electrons energy spectra. The portable analyzer with a unique set of parameters such as small size (10*10*1 mm), low cost, a wide range of recognizable molecules, great measurement accuracy at the atmospheric pressure can be effectively used both for rapid testing of air pollution load and the study of noxious factors that influence oil and gas industry employees. [Preview Abstract] 

YP11.00050: Hydroscaling of DT implosions on the National Ignition Facility Pravesh Patel, Brian Spears, Dan Clark Recent implosion experiments on the National Ignition Facility (NIF) exceed 50 kJ in fusion yield and exhibit yield amplifications of \textgreater 2.53x due to alphaparticle selfheating of the hotspot. Two methods to increase the yield are (i) to improve the implosion quality, or stagnation pressure, at fixed target scale (by increasing implosion velocity, reducing 3D effects, etc.), and (ii) to hydrodynamically scale the capsule and absorbed energy. In the latter case the stagnation pressure remains constant, but the yieldin the absence of alphaheatingincreases as Y\textasciitilde S\textasciicircum 4.5, where the capsule radius is increased by S, and the absorbed energy by S\textasciicircum 3. With alphaheating the increase with scale is considerably stronger. We present projections in the performance of current DT experiments, and the extrapolations to ignition, based on applying hydroscaling theory and accounting for the effect of alphaheating. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DEAC5207NA27344. [Preview Abstract] 

YP11.00051: Magnetic nanomotor fabrication by plasma coating method and its biological application Lutfi Oksuz, Gozde Yurdabak Karaca, Emre Uygun, Aysegul Uygun Oksuz Nano/micro scale motors are exciting research area due to a wide range of application area especially offer considerable promise for the diagnosis and treatment of the diseases. In this scope, the preparation and characterization of Gold (Au)/ Nickel (Ni) nanomotors transport and their applications based on the detection of miRNA21 will be examined. In addition, magnetic segment Ni which was coated by RF magnetron sputter technique on to the electrochemical synthesized Au nanowire can also be used to focus on the controlled movement and target. We propose a sensitive stable plasma coated magnetic nanomotorbased approach for miRNA21 detection for simple and cancer diagnosis. [Preview Abstract] 

YP11.00052: Determination of the profit rate of plasma treated production in the food sector Elif Ceren Gok, Emre Uygun, Esin Eren, Lutfi Oksuz, Aysegul Uygun Oksuz Recently, plasma is one of an emerging, green processing technologies used for diverse applications especially food industry [1]. Plasma treatment proposes diverse opportunities in food industry such as surface decontamination, modification of surface properties and improvement in mass transfer with respect for foods and foodrelated compounds [1]. Sometimes manufacturers use chemical treatment to demolish pathogenic flora, but its capabilities are rather limited. New methods of food sterilization consisting of ionizing radiation, exposure to magnetic fields, highpower ultrasonic treatment are needed expensive equipment or have not yet been developed for industrial use. Plasma could be used for the above mentioned reasons. In this study, the profit rate of plasma treated production in food sector was calculated. References [1] S. A. Mir, M. A. Shah, M. M. Mir, Food Bioprocess Technol, DOI 10.1007/s1194701616999 [Preview Abstract] 

YP11.00053: Sheath and bulk expansion induced by RF bias in atmospheric pressure microwave plasma Jimo Lee, Woojin Nam, Jae Koo Lee, Gunsu Yun A large axial volume expansion of microwavedriven plasma at atmospheric pressure is achieved by applying a low power radio frequency (RF) bias at an axial location well isolated from the original plasma bulk. The evolution of the plasma plume visualized by high speed ICCD imaging suggest that the free electrons drifting toward the bias electrode cause the prodigious expansion of the sheath, creating a stable plasma stream channel between the microwave and the RF electrodes. For argon plasma in ambient air, enhanced emissions of OH and N$_2$ spectral lines are measured in the extended plume region, supporting the acceleration of electrons and subsequent generation of radical species. The coupling of RF bias with microwave provides an efficient way of enlarging the plasma volume and enhancing the production of radicals. [Preview Abstract] 

YP11.00054: Mechanisms generating kappa distributions in plasmas. Georgios Livadiotis Kappa distributions have become increasingly widespread across plasma physics. Publication records reveal an exponential growth of papers relevant to kappa distributions. However, the vast majority of publications refer to statistical fits and applications of these distributions in plasmas. Up to date, there is no systematic analysis on the origin of kappa distributions, that is, the mechanisms that can generate kappa distributions in plasmas. The general scheme that characterizes these mechanisms is composed of two parts: (1) the generation of local correlations among particles, and (2) the thermalization, that is, the stabilization of the particle system into stationary states described by kappa distributions or combinations thereof. Several mechanisms are known in the literature, each characterized by a specific relationship between the plasma properties. These relationships serve as conditions that need to be fulfilled for the corresponding mechanisms to be applied in the plasma. Using these relationships, we identify three mechanisms that generate kappa distributions in the solar wind plasma: (i) Debye shielding, (ii) magnetic field binding, and (iii) thermal fluctuations, each one prevailing in different scales of the solar wind plasma and magnetic field properties. [Preview Abstract] 

YP11.00055: Imaging and spectroscopy of optical transition radiation from thin foils irradiated by ultraintense laser pulse Leejin Bae, Minsang Cho, Yelim Ji, Gyeongbo Kang, Minju Kim, Seonghyeok Yang, Chuinhong Yap, Byoungick Cho, Cheonha Jeon Optical transition radiation (OTR) by relativistic electrons emerging the rear surface of target conveys numerous information on lasertarget interaction. Imaging of the radiation shows the spatial distribution of hot electron beams. Spectrum of OTR infers the temporal structure of relativistic electron bunches. In this contribution, we present the OTR images and spectra from foil target with various thickness (100 nm  10 um) irradiated by intense laser pulses up to 10$^{\mathrm{20}}$ W/cm$^{\mathrm{2}}$. The significant modulation on OTR shape and spectra are observed from nanofoils at extremely high intensity. Prepulses also introduce significant difference in OTR spectra. Detailed data and possible mechanism for such modulations will be presented. [Preview Abstract] 

YP11.00056: Liquid Plasma Synthesis of Carbon Coated Iron Oxide Particles Aysegul Uygun, Noah Hershkowitz, Esin Eren, Emre Uygun, Gamze Celik Cogal, Gozde Yurdabak Karaca, Sorin Manolache, Gunasekaran Sundaram, Omer Sadak, Lutfi Oksuz Recently, magnetic metal or metal oxide nanoparticles encapsulated in carbon are important in biomedical applications [1]. The relevant reason to study toxicity of the magnetic nanoparticles coated by carbon is that they have great potential to contribute to cancer treatment. In this work, the synthesis of iron oxide nanoparticles coated by graphitic carbon shells using pulsed plasma in liquid method. Short duration of RF plasma discharge, low electrical energy and fast quenching of the surrounding media can let to synthesize various kinds of pure nanoparticles. *Corresponding author: ayseguluygun@sdu.edu.tr,lutfioksuz@sdu.edu.tr [1] S S khiabani et al., Artificial cells, nanomedicine and biotechnology, 45,1, 617 (2017) [Preview Abstract] 

YP11.00057: 2D HighResolution Measurement of High GuideField Magnetic Reconnection in TS3U Spherical Tokamak Merging Experiment Qinghong Cao, Moe Akimitsu, Asuka Sawada, Hiroshi Tanabe, Yasushi Ono The TS3U experiment performs magnetic reconnection with a strong guide field by merging two spherical tokamak plasmas. To observe the 2D configuration of the current sheet, we developed a highresolution 2D magnetic probe array with 260 channels, arranged into 13x10 Bz components and 13x10 Br components, with up to 5 mm spatial resolution spread over a 40 cm x 30 cm poloidal area. The current density $J_{t}$ , the electric field $E_{t}$, and the current sheet’s effective resistivity $\eta_{eff} (= \frac{E_{t}}{J_{t}})$ will therefore be followed during the reconnection process. Under a strong guide magnetic field, the sheet resistivity is expected to be almost classical because the sheet thickness is much larger than the ion gyroradius. But resistivity is observed to be anomalous with pileup and plasmoid formation appearing to regulate the reconnection speed. The anomalous increase in resistivity is being studied as a possible cause for the high power heating of fast magnetic reconnection. [Preview Abstract] 

YP11.00058: Application of nonlocal plasma technology for controlling plasma conductivity. Chengxun Yuan, V. I. Demidov, A. A. Kudryavtsev, I. P. Kurlyandskaya, T. V. Rudakova, Z. X. Zhou A promising approach for better control of the plasma parameters involves the exploitation of peculiarities of plasmas with a nonlocal electron energy distribution. ~Nonlocal plasma technology (NLPtechnology) is based on the effect of energetic electrons in the plasma volume. In this work, an experimental study of influence of the chemoionization processes on nonstationary plasma conductivity has been conducted. Due to energetic, suprathermal electrons, which appear in the chemoionization reactions, the highly nonequilibrium and time dependent nonlocal electron energy distribution function is formed. In such a plasma thermal electrons always have positive conductivity (mobility), while suprathermal, energetic electrons may have negative conductivity in heavy (argon, krypton and xenon) noble gases dependently on conditions. Experiments demonstrate that this effect may lead to the nonmonotonic temporal behavior of plasma conductivity and may potentially create the negative electron mobility. [Preview Abstract] 

YP11.00059: Semiconductor nanostructures for plasma energetic systems Alexander Mustafaev, Rostislav Smerdov, Boris Klimenkov In this talk we discuss the research results of the three types of ultrasmall electrodes namely the nanoelectrode arrays based on composite nanostructured porous silicon (PS) layers, porous GaP and nanocrystals of ZnO. These semiconductor materials are of great interest to nano and optoelectronic applications by virtue of their high specific surface area and extensive capability for surface functionalization. The use of semiconductor (GaN) cathodes in photonenhanced thermionic emission systems has also proved to be effective although only a few (less than 1\%) of the incident photons exceed the 3.3 eV GaN band gap. This significant drawback provided us with a solid foundation for our research in the field of nanostructured PS, and composite materials based on it exhibiting nearly optimal parameters in terms of the band gap (1.1 eV). The band gap modification for PS nanostructured layers is possible in the range of less than 1 eV and 3 eV due to the existence of quantum confinement effect and the remarkable possibilities of PS surface alteration thus providing us with a suitable material for both cathode and anode fabrication. The obtained results are applicable for solar concentration and thermionic energy conversion systems. [Preview Abstract] 

YP11.00060: Nonlinear excitation of fast magnetosonic waves via quasielectrostatic whistler wave mixing Nathan Zechar, Vladimir Sotnikov, James Caplinger, Arthur Chu We report on experiments of nonlinear simultaneous generation of low frequency fast magnetosonic waves and electromagnetic whistler waves using two loop antennas in the afterglow of a cold magnetized helium plasma. The exciting antennas each have a frequency that is below half the electron cyclotron frequency, and the difference between the two is just below the lower hybrid frequency. They both directly excite whistler waves, however their nonlinear interaction excite the low frequency fast magnetosonic waves at the frequency given by their difference. Plasma is generated using a helicon plasma source in a one meter length cylindrical chamber. The spatial and temporal data of the electromagnetic and electrostatic components of the plasma waves are then captured with developed diagnostic techniques. Wave spectra, general structure and time domain frequencies observed will be reported. [Preview Abstract] 

YP11.00061: Development of highresolution twodimensional magnetic field measurement system by use of printedcircuit technology Moe Akimitsu, Cao Qinghong, Asuka Sawada, Hironori Hatano, Hiroshi Tanabe, Yasushi Ono We have developed a newtypes of highresolution magnetic probe array for our new magnetic reconnection experiments: TS3U (ST, FRC: R$=$0.2m, 2017) and TS4U (ST, FRC: R$=$0.5m, 2018), using the advanced printedcircuit technology. They are equipped with all threecomponents of magnetic pickup coils whose size is 15mm x 3mm. Each coil is composed of twosided coil pattern with line width of 0.05mm. We can install two or three printed arrays in a single glass (ceramic) tube for two or three component measurements. Based on this new probe technique, we started highresolution and highaccuracy measurement of the current sheet thickness and studied its plasma parameter dependence. We found that the thickness of current sheet increases inversely with the guide toroidal field. It is probably determined by the ion gyroradius in agreement with the particle simulation by Horiuchi etc. While the reconnection speed is steady under low guide field condition, it is observed to oscillate in the specific range of guide field, suggesting transition from the quasisteady reconnection to the intermittent reconnection. Cause and mechanism for intermittent reconnection will be discussed using the current sheet dissipation and dynamic balance between plasma inflow and outflow. [Preview Abstract] 

YP11.00062: Geodesic eigenmodes and ion temperature fluctuations in a tokamak A. Smolyakov, S. Janhunen, V. Ilgisonis, I. Khalzov, V. Lakhin, E. Sorokina It is shown analytically that in addition to the standard Geodesical Acoustic Modes (GAM) oscillations, there are exist low frequency radially propagating fluctuations of the mean (poloidally averaged) ion temperature. Radial propagation of the ion temperature mode is supported by the ion (radial) heat flux, while the restoring force is created by the radial current due to the ion diamagnetic velocity. The structure of the global GAM and radial propagation is studied numerically with the MHD and gyrokinetic theory. [Preview Abstract] 

YP11.00063: Global electrostatic potential structures of merging flux tubes in TSU torus plasma merging experiment Asuka Sawada, Hironori Hatano, Moe Akimitsu, Qinghong Cao, Kotaro Yamasaki, Hiroshi Tanabe, Yasushi Ono We have been investigating 2D potential profile of global merging tokamaks to solve highpower heating of magnetic reconnection in TS3 and TS3U (ST, FRC:R$=$0.2m, 1985, 2017) and TS4 (ST, FRC:R$=$0.5m, 2000), UTST (ST:R$=$0.45m, 2008) and MAST (ST:R$=$ 0.9m, 2000) devices. These experiments made clear that the electrostatic potential well is formed not only in the downstream area of magnetic reconnection but also in the whole common (reconnected) flux area of two merging flux tubes: tokamak plasmas. This fact suggests that the ion acceleration/heating occurs in much wider region than the reconnection downstream. We studied how the potential structure depends on key reconnection parameters:guide toroidal field and plasma collisionality. We found the polarity of the guide toroidal field determines those of potential hills and wells, indicating their formation is affected by the Hall effect. The peak value of the electrostatic potential well decreased with gas pressure increasing, suggesting plasma collisionality suppresses the Hall effect. The relationship between the electrostatic potential structure and anomalous ion heating is being studied as a possible cause for the highpower heating of fast magnetic reconnection. [Preview Abstract] 

YP11.00064: Evolution of multimode perturbations in spherical implosions Markus Flaig, Ben Thornber In this project, the growth of perturbations on the inner interface of a dense imploding shell is studied by means of high resolution threedimensional numerical simulations using the AMR codes PLUTO and FLASH. We consider broadband and narrowband initial perturbations with mode numbers up to $\ell=200$. Perturbation growth happens as a consequence of RichtmyerMeshkov instability seeded by the incident shock and subsequent reshocks, as well as RayleighTaylor instability as the interface is decelerated near stagnation. We report on the evolution of the mix layer width, the atomic mix and the turbulent kinetic energy. For the case of broadband initial perturbations, a smallamplitude analysis that is valid beyond reshock is applied to predict the evolution of the mix layer width and to quantify the impact of RT/RM instabilities and convergence and compression effects on the mix layer growth. Finally, it is shown that the mix layer growth is well represented by a justsaturated mode model. [Preview Abstract] 

YP11.00065: Laserdriven ion acceleration at BELLA Jianhui Bin, Sven Steinke, Qing Ji, Kei Nakamura, Franziska Treffert, Stepan Bulanov, Markus Roth, Csaba Toth, Carl Schroeder, Eric Esarey, Thomas Schenkel, Wim Leemans BELLA is a high repetiton rate PW laser and we used it for high intensity laser plasma acceleration experiments. The BELLAi program is focused on relativistic laser plasma interaction such as laser driven ion acceleration, aiming at establishing an unique collaborative research facility providing beam time to selected external groups for fundamental physics and advanced applications. Here we present our first parameter study of ion acceleration driven by the BELLAPW laser with truly high repetition rate. The laser repetition rate of 1Hz allows for scanning the laser pulse duration, relative focus location and target thickness for the first time at laser peak powers of above 1 PW. Furthermore, the long focal length geometry of the experiment (f$\backslash $65) and hence, large focus size provided ion beams of reduced divergence and unprecedented charge density. This work was supported by the Director, Office of Science, of the U.S. Department of Energy under Contract No. DEAC0205CH11231. [Preview Abstract] 

YP11.00066: Measurements of Ion and Neutral Fluctuation Changes with Pressure in a LargeScale Helicon Plasma R.H. Dwyer, D.M. Fisher, R.F. Kelly, M.W. Hatch, M. Gilmore Neutral particle dynamics may play an important role both in laboratory plasmas and in the edge of magnetic fusion devices. However, studies of neutral dynamics in these plasmas have been limited to date. Here we report on a basic study of ion and neutral fluctuations as a function of background neutral gas pressure. These experiments have been conducted in helicon discharges in the HelCat (HeliconCathode) dualsource plasma device at the University of New Mexico. The goal is to measure changes in ion and neutral density fluctuations with pressure and to gain an improved understanding of plasmaneutral interactions. Langmuir probe, ArI LIF, and highspeed imaging measurements of the fluctuations will be presented. [Preview Abstract] 

YP11.00067: Rapid Evolution of SmallScale Flows in Solar Granulation Riley Heiman We used local correlation tracking to estimate horizontal velocities in an image sequence of convection at the solar photosphere, at high spatial and temporal resolution (0.034'' pixels and 10second cadence, respectively) observed in TiO (705.7 nm) with the Goode Solar Telescope. A key goal of our study was to estimate the lifetimes of flows in granules, which have implications for models of coronal heating that rely upon rapid evolution in photospheric forcing of coronal magnetic field evolution. We estimate flow lifetimes by fitting the decorrelation times of flow maps. For LCT apodization windows near 200 km (8 pixels), we find flow lifetimes of about 60 sec. On these scales, we also find flow speeds consistent with previous reports, of order a few km/sec. With the LCT apodization window set to 100 km (4 pixels), we found flows to be faster and shorterlived. The observed flow evolution is therefore rapid enough to excite turbulent interaction between upward and downwardpropagating Alfv\'{e}n waves between the photosphere and corona, consistent with the predictions of a coronal heating model proposed by van Ballegooijen et al. (2011). [Preview Abstract] 

YP11.00068: Visible Spectroscopy Measurements of Plasmas and Fields in the Power Flow Regions on the ZMachine Mark Johnston, Sonal Patel, Ross Falcon, Keith Cartwright, Mark Kiefer, Mike Cuneo, S. Biswas, R. Doron, D. Mikitchuk, E. Stambulchik, Yitzhak Maron In order to better understand the physics involved with efficient high current delivery to a load, there is an effort underway at Sandia National Laboratories to study plasma formation and propagation in the power flow regions on the ZMachine. Experiments are being conducted using streaked, visible spectroscopy to obtain time histories of plasma formation and propagation throughout the final power flow regions on Z, where currents and fields are at their highest. Plasmas draw current away from the load, causing the machine to be less efficient; depending on the specific load, losses of up to 20\% can occur. This paper describes the first comprehensive attempt to characterize these plasmas on Z. We outline the experimental techniques used to make these measurements, provide results obtained to date, and draw comparisons with hybrid fluidPIC simulations.\\ \\Sandia National Laboratories is a multimission laboratory managed and operated by National Technology and Engineering Solutions of Sandia LLC, a wholly owned subsidiary of Honeywell International Inc. for the U.S. Department of Energy’s National Nuclear Security Administration under contract DENA0003525 [Preview Abstract] 

YP11.00069: Laserdriven ultrafast multiMeV gammaray beam generation. Jiancai Xu, Baifei Shen, Tongjun Xu, Shun Li, Yong Yu, Jinfeng Li, Xiaoming Lu, Cheng Wang, Xinliang Wang, Xiaoyan Liang, Yuxin Leng, Ruxin Li, Zhizhan Xu Ultrafast multiMeV highflux gammaray beams have been experimentally produced via bremsstrahlung radiation of laseraccelerated energetic electrons through millimeterthick copper targets. By optimizing the electron bunches to the charge of 10 nC in a clustering argon gas target, the obtained gammaray beam significantly increases to 10$^{\mathrm{10}}$ photons per shot. The gammaray beam spectrum has been measured using a differential filtering detector and has a broad spectrum up to 15 MeV, which is approximately consistent with the Geant4 simulation. The generated highflux highenergy gammaray beams are promising sources for photonuclear reaction, nondestructive inspection and clinical applications. \\ \\Tongjun Xu, Baifei Shen, Jiancai Xu, \textit{et al.}, \textit{Phys. Plasmas} 23, 033109 (2016). \item Shun Li, Baifei Shen, Jiancai Xu, \textit{et al.}, Ultrafast multiMeV gammaray beam produced by laseraccelerated electrons (submitted). [Preview Abstract] 

YP11.00070: Understanding current drive and penetration with rotating fields: singleparticle electron orbits Peter Jandovitz, S. A. Cohen In an effort to understand current drive and penetration with rotating magnetic fields, we examined singleparticle electron orbits under different conditions. It was found to be difficult to reconcile the singleparticle picture with fluid theory and experimental results, and the penetration and current drive mechanisms associated with oddparity RMF are still unclear. Future PIC simulations and experiments will hopefully shed light on these questions. [Preview Abstract] 

YP11.00071: Laboratory Photoionization Fronts in Nitrogen Gas William Gray, Paul Keiter, Cody Patterson, Joshua Davis, Paul Drake Photoionization fronts play a dominant role in many astrophysical situations, but remain difficult to achieve in a laboratory experiment. We present the results from a computational parameter study evaluating the feasibility of the proposed laboratory experiments of Drake et.al (2016). The nitrogen gas density and the Planckian radiation temperature of the source that generates the xray flux, define each simulation. Computational simulations modeled experiments in which the xray flux is generated by a laserheated gold foil, suitable for experiments using many kJ or of laser energy, and also experiments in which the flux is generated by a ``zpinch'' device, which implodes a cylindrical shell of conducting wires. The models are run using crash, our blockadaptivemesh code for multimaterial radiation hydrodynamics. The radiative transfer model uses multigroup flux limited diffusion with thirty radiation groups. In addition, electron heat conduction is modeled using a singlegroup, fluxlimited diffusion. In the theory, a photoionization front can exist only when the ratios of the electron recombination to the photoionization flux and the electron collisional ionization rate to the recombination rate lie in certain range . [Preview Abstract] 
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