American Institute of Physics: Physics of Plasmas

Physics of Plasmas: All Topics

Radiation generated by bunched electron beams in corrugated plasma channels
Thomas M. Antonsen, Jr. The excitation of radiation by bunched electron beams propagating in miniature corrugated plasma channels is considered. It is shown that the rate at which power is radiated by a beam is characterized by impedance that depends on the properties of the channel. For experimentally obtainable parameter ... [Phys. Plasmas 17, 073112 (2010)] published Fri Jul 30, 2010.
Turbulence driven magnetic reconnection causing long-wavelength magnetic islands
A. Ishizawa and N. Nakajima Magnetic reconnection caused by turbulence in a current sheet is studied by means of numerical simulations of fluid equations. It is found that turbulence produces long-wavelength magnetic islands even if the current sheet is so thick that spontaneous magnetic reconnection does not occur. Thus, turb ... [Phys. Plasmas 17, 072308 (2010)] published Fri Jul 30, 2010.
Role of electronic excitation on thermodynamic and transport properties of argon and argon-hydrogen plasmas
Kuldip Singh, Gurpreet Singh, and Rohit Sharma Thermodynamic and electron transport properties of the argon and argon-hydrogen plasmas have been calculated under the local thermodynamic equilibrium conditions in temperature range of 10 00040 000 K over the wide range of pressures. Electronic excitation affects strongly these properties especiall ... [Phys. Plasmas 17, 072309 (2010)] published Fri Jul 30, 2010.
Investigation of the transport properties of metals in the biphase region
V. I. Oreshkin, A. G. Rousskikh, S. A. Chaikovsky, and E. V. Oreshkin Results of experiments on electrical wire explosion are presented and processes of stratum formation and decay are analyzed in this paper. A procedure of calculating the transport coefficients from the rate of stratum damping is described. It is demonstrated that values of the transport coefficients ... [Phys. Plasmas 17, 072703 (2010)] published Fri Jul 30, 2010.
Correlation between laser accelerated MeV proton and electron beams using simple fluid model for target normal sheath acceleration
M. Tampo, S. Awano, P. R. Bolton, K. Kondo, K. Mima et al. High density energetic electrons that are created by intense laser plasma interactions drive MeV proton acceleration. The correlation between accelerated MeV protons and escaped electrons is experimentally investigated at laser intensities in the range of 1010 W/cm with S-polarization. Observed pro ... [Phys. Plasmas 17, 073110 (2010)] published Thu Jul 29, 2010.
A computational study of x-ray emission from laser-irradiated Ge-doped foams
Jeffrey D. Colvin, Kevin B. Fournier, Mark J. May, and Howard A. Scott New advances in fabrication of low-density high-Z-doped foams have opened new windows on understanding how materials that are not in local thermodynamic equilibrium (LTE) are heated and radiate. Simulations are discussed in this paper of the x-ray spectral emissions from laser-irradiated very low-de ... [Phys. Plasmas 17, 073111 (2010)] published Thu Jul 29, 2010.
Drift-Alfven waves induced optical emission fluctuations in Aditya tokamak
R. Manchanda, J. Ghosh, P. K. Chattopadhyay, M. B. Chowdhuri, Santanu Banerjee et al. In Aditya tokamak [S. B. Bhatt et al. Indian J. Pure Appl. Phys. 27, 710 (1989)], an increase in the H and C intensity fluctuations from the edge region is observed with an increase in the magnetohydrodynamic (MHD) activity. Very small fluctuation amplitudes of H and C intensity are observed in disc ... [Phys. Plasmas 17, 072515 (2010)] published Thu Jul 29, 2010.
Fluctuation of charge on dust particles in a complex plasma
M. S. Sodha, S. K. Mishra, Shikha Misra, and Sweta Srivastava This paper presents an analytical model for the evaluation of the fluctuation of the charge on the dust particles in a complex plasma. In contrast to earlier analyses, which ignored the effect of dust particles on density and temperature of electrons and ions, the present model takes into account th ... [Phys. Plasmas 17, 073705 (2010)] published Thu Jul 29, 2010.
On the cubic zero-order solution of electromagnetic waves. I. Periodic slabs with lossy plasmas
Hyoung-In Lee (이형인) and Jinsik Mok (목진식)
Electromagnetic waves are considered for periodic structures consisting of lossy plasmonic components and dielectric host media. For the plasmonic components, not only low-loss metals but also high-loss gas plasmas are taken into consideration. For small filling fractions of the plasmonic components ... [Phys. Plasmas 17, 072108 (2010)] published Thu Jul 29, 2010.
On the cubic zero-order solution of electromagnetic waves. II. Isolated particles with lossy plasmas
Hyoung-In Lee (이형인) and Jinsik Mok (목진식)
Electromagnetic waves are examined for a single isolated nanoparticle, which is composed of lossy plasmonic components and immersed in an unbounded homogeneous dielectric host medium. Wave characteristics thus obtained on resonance play crucial roles as the zero-order solution for periodic structure ... [Phys. Plasmas 17, 072109 (2010)] published Thu Jul 29, 2010.
Nonplanar converging and diverging shock waves in the presence of thermal ions in electron-positron plasma
Asif Shah, R. Saeed, and Muhammad Noaman-ul-Haq The cylindrical and spherical Kortewegde VriesBurger equations have been derived to study the ion acoustic converging and diverging shock waves. The considered plasma is comprised of inertialess electrons, positrons, and inertial thermal ions. It is noticed that the ion temperature, positron concent ... [Phys. Plasmas 17, 072307 (2010)] published Thu Jul 29, 2010.
Tritium minority heating with mode conversion of fast waves
Carmine Castaldo and Alessandro Cardinali A new ion-heating scenario in tokamak plasmas, based on cyclotron damping of ion Bernstein waves (IBWs) by tritium minority at the first ion cyclotron harmonic (i.e., omega=2Omega), is proposed. The IBWs are coupled by mode conversion of fast magnetosonic waves in a D-H(T) (tritium minority in hydro ... [Phys. Plasmas 17, 072513 (2010)] published Tue Jul 27, 2010.
PfirschSchluter impurity transport in stellarators
S. Braun and P. Helander The PfirschSchluter transport of impurities is calculated for stellarator geometry. Contrary to the tokamak case, where the only contribution to the particle flux arises from friction between different species, in a stellarator there is another source of impurity transport due to pressure anisotropy ... [Phys. Plasmas 17, 072514 (2010)] published Tue Jul 27, 2010.
Dust-ion-acoustic shock and solitary waves in a dusty electronegative plasma
A. A. Mamun and S. Tasnim A dusty electronegative plasma containing Boltzmann electrons, Boltzmann negative ions, warm positive ions, and charge fluctuating (negatively charged) stationary dust has been considered. The basic features of the shock and solitary waves, which are associated with positive ion dynamics and dust ch ... [Phys. Plasmas 17, 073704 (2010)] published Tue Jul 27, 2010.
The mechanisms of electron acceleration in antiparallel and guide field magnetic reconnection
Can Huang, Quanming Lu, and Shui Wang Two-dimensional particle-in-cell simulations are performed to investigate electron dynamics in antiparallel and guide field (in the presence of a strong guide field) magnetic reconnection, and the mechanisms of electron acceleration are compared. In the antiparallel reconnection, the dominant accele ... [Phys. Plasmas 17, 072306 (2010)] published Tue Jul 27, 2010.
Quasitransient backward Raman amplification of powerful laser pulses in dense plasmas with multicharged ions
V. M. Malkin and N. J. Fisch The range of plasma parameters, where the efficient quasitransient backward Raman amplification (QBRA) of powerful laser pulses is possible, is determined for dense plasmas with multicharged ions. Approximate scalings that portray in a simple way the efficient QBRA range in multidimensional paramete ... [Phys. Plasmas 17, 073109 (2010)] published Tue Jul 27, 2010.
High frequency electromagnetic modes in a weakly magnetized relativistic electron plasma
Gohar Abbas, G. Murtaza, and R. J. Kingham Using the linearized VlasovMaxwell model, the polarization tensor for a weakly magnetized electron plasma is derived. For isotropic relativistic Maxwellian velocity distribution function, dispersion relations are obtained for both parallel and perpendicular propagations. The integrals (called Meijer ... [Phys. Plasmas 17, 072105 (2010)] published Tue Jul 27, 2010.
Experimental studies on ion acceleration and stream line detachment in a diverging magnetic field
K. Terasaka, S. Yoshimura, K. Ogiwara, M. Aramaki, and M. Y. Tanaka The flow structure of ions in a diverging magnetic field has been experimentally studied in an electron cyclotron resonance plasma. The flow velocity field of ions has been measured with directional Langmuir probes calibrated with the laser induced fluorescence spectroscopy. For low ion-temperature ... [Phys. Plasmas 17, 072106 (2010)] published Tue Jul 27, 2010.
Linear and nonlinear development of m=0 instability in a diffuse Bennett Z-pinch equilibrium with sheared axial flow
I. Paraschiv, B. S. Bauer, I. R. Lindemuth, and V. Makhin The effect of sheared axial flow on the Z-pinch sausage instability has been examined with two-dimensional magnetohydrodynamic simulations. Diffuse Bennett equilibria in the presence of axial flows with parabolic and linear radial profiles have been considered, and a detailed study of the linear and ... [Phys. Plasmas 17, 072107 (2010)] published Tue Jul 27, 2010.
Electric field-free gas breakdown in explosively driven generators
Sergey I. Shkuratov, Jason Baird, Evgueni F. Talantsev, and Larry L. Altgilbers All known types of gas discharges require an electric field to initiate them. We are reporting on a unique type of gas breakdown in explosively driven generators that does not require an electric field. ... [Phys. Plasmas 17, 074504 (2010)] published Mon Jul 26, 2010.
Characteristics of electron near-wall transport under two-dimensional dynamic sheath in a Hall effect thruster
Hong Li (李鸿), Fengkui Zhang (张凤奎), Hui Liu (刘辉), and Daren Yu (于达仁)
It is demonstrated that the features of measured electron current profile in the near-wall region of a Hall effect thruster are mainly due to the substantive breakdown of electron Hall drifts caused by the azimuthal field of the two-dimensional dynamic sheath. This kind of cross-field diffusion show ... [Phys. Plasmas 17, 074505 (2010)] published Mon Jul 26, 2010.
Kinetic simulation of thermonuclear-neutron production by a 10-A deuterium Z pinch
D. R. Welch, D. V. Rose, C. Thoma, R. E. Clark, C. B. Mostrom et al. Fully kinetic simulations have demonstrated that at sufficiently high currents, half of the neutrons produced by a deuterium Z-pinch are thermonuclear in origin. At 150-kA pinch current, O. A. Anderson et al. [Phys. Rev. 110, 1375 (1958)] clearly shows that essentially all of the neutrons produced b ... [Phys. Plasmas 17, 072702 (2010)] published Mon Jul 26, 2010.
Quantum screening effects on the ion-ion collisions in strongly coupled semiclassical plasmas
Dae-Han Ki and Young-Dae Jung The quantum screening effects on the ion-ion collisions are investigated in strongly coupled semiclassical hydrogen plasmas. The method of stationary phase and effective interaction potential containing the quantum mechanical effect are employed to obtain the scattering phase shift and scattering cr ... [Phys. Plasmas 17, 074506 (2010)] published Mon Jul 26, 2010.
Effect of the magnetic lenses on the electron current due to near wall conductivity in a Hall thruster
Zhiwen Wu (武志文), Daren Yu (于达仁), Xiangyang Liu (刘向阳), and Ningfei Wang (王宁飞)
The effect of magnetic lens on the electron current due to near wall conductivity (NWC) in a Hall thruster is studied. A Monte Carlo model is employed to simulate the effect of the large magnetic field incidence angle on the electron current. The simulation results show that the electron current due ... [Phys. Plasmas 17, 070701 (2010)] published Mon Jul 26, 2010.
Formation of electrostatic solitons, monotonic, and oscillatory shocks in pair-ion plasmas
S. Mahmood and H. Ur-Rehman The nonlinear electrostatic structures in homogeneous, unmagnetized pair-ion plasma are studied. The dissipation in the system is taken through kinematic viscosities of both pair-ion species. The one dimensional (Kortewegde VriesBurgers) KdVB equation is derived using reductive perturbation method. ... [Phys. Plasmas 17, 072305 (2010)] published Mon Jul 26, 2010.
Fluid models of impurity transport via drift wave turbulence
S. Futatani, W. Horton, S. Benkadda, I. O. Bespamyatnov, and W. L. Rowan Turbulent transport due to drift waves is a critical issue for fusion physics across all magnetic confinement geometries. Three-component fluid equations are used to find the eigenmodes and eigenfrequencies of a nonuniform, magnetized plasma with a four dimensional fluctuation vector composed of flu ... [Phys. Plasmas 17, 072512 (2010)] published Mon Jul 26, 2010.
The reduced-description particle-in-cell model for the two plasmon decay instability
H. X. Vu, D. F. DuBois, D. A. Russell, and J. F. Myatt Recently, motivated by the resurgent interest in suprathermal electron generation by two plasmon decay (TPD) in direct-drive laser-fusion [J. A. Delettrez et al., Bull. Am. Phys. Soc. 53, 248 (2008); V. A. Smalyuk et al., Phys. Rev. Lett. 100, 185005 (2008); B. Yaakobi et al., Phys. Plasmas 12, 0627 ... [Phys. Plasmas 17, 072701 (2010)] published Fri Jul 23, 2010.
Research on pinching characteristics of electron beams emitted from different cathode surfaces of a rod-pinch diode
Yi Gao, Aici Qiu, Zhong Zhang, Pengfei Zhang, Zhiguo Wang et al. The particle-in-cell code UNIPIC is used to simulate the working process of a rod-pinch diode and investigate the pinching characteristics of electron beams emitted from different cathode surfaces. The simulation results indicate that the electron beam emitted from the upstream surface pinches bette ... [Phys. Plasmas 17, 073108 (2010)] published Fri Jul 23, 2010.
Plasma control by modification of helicon wave propagation in low magnetic fields
T. Lafleur, C. Charles, and R. W. Boswell By making use of nonuniform magnetic fields, it is shown experimentally that control of helicon wave propagation can be achieved in a low pressure (0.08 Pa) expanding plasma. The m=1 helicon waves are formed during a direct capacitive to wave mode transition that occurs in a low diverging magnetic f ... [Phys. Plasmas 17, 073508 (2010)] published Fri Jul 23, 2010.
The parametric decay of Alfven waves into shear Alfven waves and dust lower hybrid waves
M. Jamil, H. A. Shah, M. Salimullah, K. Zubia, I. Zeba et al. The parametric decay instability of Alfven wave into low-frequency electrostatic dust-lower-hybrid and electromagnetic shear Alfven waves has been investigated in detail in a dusty plasma in the presence of external/ambient uniform magnetic field. Magnetohydrodynamic fluid equations of plasmas have ... [Phys. Plasmas 17, 073703 (2010)] published Thu Jul 22, 2010.
Nonlinear flow generation by electrostatic turbulence in tokamaks
W. X. Wang, P. H. Diamond, T. S. Hahm, S. Ethier, G. Rewoldt et al. Global gyrokinetic simulations have revealed an important nonlinear flow generation process due to the residual stress produced by electrostatic turbulence of ion temperature gradient (ITG) modes and trapped electron modes (TEMs). In collisionless TEM (CTEM) turbulence, nonlinear residual stress gen ... [Phys. Plasmas 17, 072511 (2010)] published Thu Jul 22, 2010.
Ultraintense ion beams driven by a short-wavelength short-pulse laser
J. Badziak and S. Jablonski The results of particle-in-cell simulations are reported which demonstrate that a short-wavelength (lambda<=0.5 [mu]m) short-pulse laser driver can produce much more intense ion beams than the commonly used long-wavelength (lambda~1 [mu]m) ones. In particular, such a driver allows for efficient ge ... [Phys. Plasmas 17, 073106 (2010)] published Thu Jul 22, 2010.
Three-dimensional parallel UNIPIC-3D code for simulations of high-power microwave devices
Jianguo Wang, Zaigao Chen, Yue Wang, Dianhui Zhang, Chunliang Liu et al. This paper introduces a self-developed, three-dimensional parallel fully electromagnetic particle simulation code UNIPIC-3D. In this code, the electromagnetic fields are updated using the second-order, finite-difference time-domain method, and the particles are moved using the relativistic NewtonLor ... [Phys. Plasmas 17, 073107 (2010)] published Thu Jul 22, 2010.
Observations of low-aberration plasma lens focusing of relativistic electron beams at the underdense threshold
M. C. Thompson, H. Badakov, J. B. Rosenzweig, G. Travish, N. Barov et al. Focusing of a 15 MeV electron bunch by a plasma lens operated at the threshold of the underdense regime has been demonstrated. The strong, 1.7 cm focal length, plasma lens focused both transverse directions simultaneously and reduced the minimum area of the beam spot by a factor of 23. It is shown t ... [Phys. Plasmas 17, 073105 (2010)] published Wed Jul 21, 2010.
Fulfillment of the kinetic Bohm criterion in a quasineutral particle-in-cell model
Eduardo Ahedo, Robert Santos, and Felix I. Parra Quasineutral particle-in-cell models of ions must fulfill the kinetic Bohm criterion, in its inequality form, at the domain boundary in order to match correctly with solutions of the Debye sheaths tied to the walls. The simple, fluid form of the Bohm criterion is shown to be a bad approximation of t ... [Phys. Plasmas 17, 073507 (2010)] published Wed Jul 21, 2010.
Ion-temperature gradient modes affected by helical magnetic field of magnetic islands
A. Ishizawa and P. H. Diamond Ion temperature gradient mode (ITG) affected by static magnetic field of magnetic islands is investigated numerically by means of Landau fluid model. The ITG is localized around O-points of magnetic islands, and the localization in poloidal direction is similar to the poloidal localization of toroid ... [Phys. Plasmas 17, 074503 (2010)] published Tue Jul 20, 2010.
Study of keV radiation properties of Mo and Ti X-pinch plasma sources using a pinhole transmission grating spectrometer
Jing Li (李晶), Jian-Jun Deng (邓建军), Wei-Ping Xie (谢卫平), Xian-Bin Huang (黄显宾), Li-Bing Yang (杨礼兵) et al.
The properties of keV x-ray radiations from Mo and Ti X-pinch plasma sources at the current of 800 kA were investigated by a pinhole transmission grating spectrometer. The spectrometer was characterized by a high linear dispersion rate (2.9 A/mm), and from its time-integrated diffraction images, ric ... [Phys. Plasmas 17, 073104 (2010)] published Mon Jul 19, 2010.
Numerical study of the plasma wall-bias effect on the ion flux through acceleration grid hole
Seung-Hoon Park and C. S. Chang In the extraction of ion beams from a source plasma through a grid acceleration structure, one of the key improvement issues is the fluence of the ion flux. Theoretical research has usually been focused on the structure of the grid system and the distribution of the electrostatic voltages over the g ... [Phys. Plasmas 17, 073505 (2010)] published Mon Jul 19, 2010.
Spacecraft charging and ion wake formation in the near-Sun environment
R. E. Ergun, D. M. Malaspina, S. D. Bale, J. P. McFadden, D. E. Larson et al. A three-dimensional, self-consistent code is employed to solve for the static potential structure surrounding a spacecraft in a high photoelectron environment. The numerical solutions show that, under certain conditions, a spacecraft can take on a negative potential in spite of strong photoelectron ... [Phys. Plasmas 17, 072903 (2010)] published Mon Jul 19, 2010.
Tunable one-dimensional plasma photonic crystals in dielectric barrier discharge
Weili Fan and Lifang Dong A tunable one-dimensional plasma photonic crystal is obtained by using a dielectric barrier discharge with two liquid electrodes. It is formed by the self-organization of the filaments, rather than that in an artificial array of electrodes. The dispersion relations of the plasma photonic crystals ar ... [Phys. Plasmas 17, 073506 (2010)] published Mon Jul 19, 2010.
Wave-number spectral scaling law of drift wave-zonal flow turbulence in gyrofluid simulations
Jiquan Li and Y. Kishimoto Wave-number spectral characteristics of ion temperature gradient (ITG) turbulence are investigated based on three-dimensional gyrofluid simulation. The focus is on the back reaction of the self-generated zonal flows (ZFs) on the ambient turbulence through nonlinear mode coupling. Detailed spectral a ... [Phys. Plasmas 17, 072304 (2010)] published Mon Jul 19, 2010.
Enhanced production of runaway electrons during electron cyclotron resonance heating and in the presence of supersonic molecular beam injection in the HL-2A tokamak
Y. P. Zhang, Yi Liu, J. W. Yang, X. Y. Song, G. L. Yuan et al. In the present paper, it is reported that a large production of runaway electrons has been observed during the flattop phase of electron cyclotron resonance heating (ECRH) discharges and in the presence of supersonic molecular beam injection (SMBI) in the HuanLiuqi-2A (commonly referred to as HL-2A) ... [Phys. Plasmas 17, 072509 (2010)] published Mon Jul 19, 2010.
Resonant field amplification with feedback-stabilized regime in current driven resistive wall mode
Yueqiang Liu, M. S. Chu, Y. In, and M. Okabayashi The stability and resonant field response of current driven resistive wall modes are numerically studied for DIII-D [J. L. Luxon, Nucl. Fusion 42, 614 (2002)] low pressure plasmas. The resonant field response of the feedback-stabilized resistive wall mode is investigated both analytically and numeri ... [Phys. Plasmas 17, 072510 (2010)] published Mon Jul 19, 2010.
Analytic model of near-field radio-frequency sheaths. II. Full plasma dielectric
D. A. D'Ippolito and J. R. Myra An analytic model is derived for electromagnetic radio-frequency (rf) wave propagation in a plasma-filled waveguide with rf sheath boundary conditions. The model gives a simplified description of the rf fields and sheath potentials near an ion cyclotron range of frequencies antenna under certain con ... [Phys. Plasmas 17, 072508 (2010)] published Fri Jul 16, 2010.
Kinetic axisymmetric gravitational equilibria in collisionless accretion disk plasmas
Claudio Cremaschini, John C. Miller, and Massimo Tessarotto A theoretical treatment is presented of kinetic equilibria in accretion disks (AD) around compact objects, for cases where the plasma can be considered as collisionless. The plasma is assumed to be axisymmetric and to be acted on by gravitational and electromagnetic fields; in this paper, the partic ... [Phys. Plasmas 17, 072902 (2010)] published Fri Jul 16, 2010.
Quantum electrodynamics vacuum polarization modification of photon acceleration in plasma
Zhigang Bu and Peiyong Ji The modification of photon frequency shifting based on taking into account the nonlinear quantum electrodynamics vacuum properties in plasma is studied. Motion equations of a laser field propagating in a plasma are derived from the HeisenbergEuler Lagrangian density. It is found that besides the cla ... [Phys. Plasmas 17, 073103 (2010)] published Fri Jul 16, 2010.
Lower hybrid destabilization of trapped electron modes in tokamak and its consequences for anomalous diffusion
Animesh Kuley, C. S. Liu, and V. K. Tripathi Parametric coupling of lower hybrid pump wave with low frequency collisionless/weakly collisional trapped electron drift wave, with frequency lower than the electron bounce frequency, is studied. The coupling produces two lower hybrid sidebands. The sidebands beat with the pump to exert a low freque ... [Phys. Plasmas 17, 072506 (2010)] published Thu Jul 15, 2010.
Magnetic signature of current carrying edge localized modes filaments on the Joint European Torus tokamak
P. Migliucci, V. Naulin, and JET EFDA Contributors Fast magnetic pickup coils are used in forward modeling to match parameters in a simple edge localized mode (ELM) filament model. This novel method allows us to determine key parameters for the evolution of the ELM filaments, as effective mode number, radial and toroidal velocities, and average curr ... [Phys. Plasmas 17, 072507 (2010)] published Thu Jul 15, 2010.
Entropy production rate in tokamaks with nonaxisymmetric magnetic fields
X. Garbet, J. Abiteboul, E. Trier, O. Gurcan, Y. Sarazin et al. A variational principle based on an extremum of entropy production rate is derived for an integrable Hamiltonian system in the presence of two perturbations, which are resonant on neighboring or identical resonant surfaces. This method can be used to calculate the neoclassical transport in a magneti ... [Phys. Plasmas 17, 072505 (2010)] published Thu Jul 15, 2010.
Experimental investigation of edge-to-center density ratio in inductively coupled plasmas
Gun-Ho Kim, Hyo-Chang Lee, and Chin-Wook Chung Edge-to-center density ratios were measured by using a floating harmonics method in inductively coupled plasma (ICP) and were compared to the theoretical model. As the gas pressure increased, the plasma density at the center increased. However, plasma density at the edge showed a different trend; it ... [Phys. Plasmas 17, 073504 (2010)] published Thu Jul 15, 2010.