Patterns of sound radiation behind pointlike charged obstacles in plasma flows
P. Guio, W. J. Miloch, H. L. Pecseli, and J. Trulsen
The electrostatic potential and plasma density variations around a pointlike charged object in a plasma flow are studied. These objects can represent small charged dust particles, for instance. The radiation patterns can be interpreted as the result of sound waves being radiated by the obstacle. Two ... [Phys. Rev. E 78, 016401 (2008)] published Thu Jul 3, 2008.
A particle simulation of current sheet instabilities under finite guide field
X. Y. Wang, Y. Lin, L. Chen, and Z. Lin
The instability of a Harris current sheet under a broad range of finite guide field (B) is investigated using a linearized (deltaf) gyrokinetic electron and fully kinetic ion particle simulation code. The simulation is carried out in the two-dimensional plane containing the guide field along y and t ... [Phys. Plasmas 15, 072103 (2008)] published Thu Jul 3, 2008.
Experiments on the Propagation of Plasma Filaments
Noam Katz, Jan Egedal, Will Fox, Ari Le, and Miklos Porkolab
We investigate experimentally the motion and structure of isolated plasma filaments propagating through neutral gas. Plasma filaments, or blobs, arise from turbulent fluctuations in a range of plasmas. Our experimental geometry is toroidally symmetric, and the blobs expand to a larger major radius u ... [Phys. Rev. Lett. 101, 015003 (2008)] published Thu Jul 3, 2008.
Streaming instabilities in multicomponent interstellar clouds
S. Ali Shan, H. Saleem, and M. Sajid
Streaming instabilities in interstellar clouds have been investigated. It is pointed out that the motion of a lighter dust species relative to a plasma containing a heavier dust species can give rise to low frequency electrostatic fluctuations. The dust ion acoustic and dust acoustic waves can becom ... [Phys. Plasmas 15, 072904 (2008)] published Wed Jul 2, 2008.
General formulation of the resistive wall mode coupling equations
V. D. Pustovitov
A theoretical framework to describe the magnetic coupling of the toroidal plasma with the resistive wall and other sources of the field asymmetry is formulated. This is done for general toroidal geometry without restrictions on the plasma, while the wall is considered as a thin shell. Mathematically ... [Phys. Plasmas 15, 072501 (2008)] published Wed Jul 2, 2008.
Modulational instabilities of electromagnetic electron cyclotron waves in a dense magnetized plasma
L. A. Rios and P. K. Shukla
Modulational instabilities of electromagnetic electron-cyclotron waves in a dense magnetized plasma are investigated. Dispersion relations for the modulational instabilities are derived and analyzed. The effects of quantum statistical pressure and quantum electron tunneling are discussed. ... [Phys. Plasmas 15, 074501 (2008)] published Wed Jul 2, 2008.
Anomalous transport of particles in plasma flow with strong inhomogeneous velocity shear
V. S. Mikhailenko, V. V. Mikhailenko, K. N. Stepanov, and N. A. Azarenkov
The temporal evolution of the drift modes and resulting anomalous transport are considered under the conditions of strong inhomogeneous flow shear [flow shear parameter dv(r)/dr is greater or comparable to the drift frequency] on the ground of the nonmodal approach with application to boundary regio ... [Phys. Plasmas 15, 072102 (2008)] published Wed Jul 2, 2008.
Effect of gas pressure on ion flux in 2 MHz capacitive discharge
I. V. Schweigert
We have studied the ion energy and angular distribution functions in a 2 MHz capacitive discharge using combined particle in cell Monte Carlo collision simulations. We found that secondary electrons produced by ion bombardment from the electrodes make important contribution to the ionization at hig ... [Appl. Phys. Lett. 92, 261501 (2008)] published Wed Jul 2, 2008.
Laser-rf creation and diagnostics of seeded atmospheric pressure air and nitrogen plasmas
Siqi Luo, C. Mark Denning, and John E. Scharer
A laser initiation and radio frequency (rf) sustainment technique has been developed and improved from our previous work to create and sustain large-volume, high-pressure air and nitrogen plasmas. This technique utilizes a laser-initiated, 15 mTorr partial pressure tetrakis (dimethylamino) ethylene ... [J. Appl. Phys. 104, 013301 (2008)] published Wed Jul 2, 2008.
Equation-of-State Measurement of Dense Plasmas Heated With Fast Protons
G. M. Dyer, A. C. Bernstein, B. I. Cho, J. Osterholz, W. Grigsby et al.
Using an ultrafast pulse of mega-electron-volt energy protons accelerated from a laser-irradiated foil, we have heated solid density aluminum plasmas to temperatures in excess of 15 eV. By measuring the temperature and the expansion rate of the heated Al plasma simultaneously and with picosecond tim ... [Phys. Rev. Lett. 101, 015002 (2008)] published Wed Jul 2, 2008.
Global plasma simulations using dynamically generated chemical models
James J. Munro and Jonathan Tennyson
Extensive molecular data are a key requirement in understanding modern technical plasmas. A method for coupling molecular data with chemical models in a global plasma simulation to enable rapid testing and evaluation of new plasmas is presented. A global plasma model (GLOBALKIN) is extended using an ... [J. Vac. Sci. Technol. A 26, 865 (2008)] published Tue Jul 1, 2008.
Compact two-stream generator of millimeter- and submillimeter-wave radiation
Bruce E. Carlsten, Kip A. Bishofberger, and Rickey J. Faehl
A novel approach to producing short-wavelength radiation is proposed, where two offset electron beams of slightly different energies are merged within a dipole magnet and interact. With proper modulation of the two beams, the two-stream instability can be exploited to efficiently generate narrow-ban ... [Phys. Plasmas 15, 073101 (2008)] published Tue Jul 1, 2008.
Drift instabilities in current sheets with guide field
P. H. Yoon and A. T. Y. Lui
Drift instabilities in current sheets with or without the guide field are investigated with a newly developed improved electrostatic dispersion relation. Traditional (local) theories of lower-hybrid drift instability typically assumes small electron drift speed, and expand the electron distribution ... [Phys. Plasmas 15, 072101 (2008)] published Tue Jul 1, 2008.
Electron Self-Reinforcing Process of Magnetic Reconnection
Weigang Wan and Giovanni Lapenta
The growth of collisionless magnetic reconnection is discovered to be a nonlinear electron self-reinforcing process. Accelerated by the reconnection electric field, the small portion of energetic electrons in the vicinity of the X point are found to be the cause of the fast reconnection rate. This n ... [Phys. Rev. Lett. 101, 015001 (2008)] published Tue Jul 1, 2008.
Electron kinetic effects in plasma expansion and ion acceleration
T. Grismayer, P. Mora, J. C. Adam, and A. Heron
The one-dimensional expansion of a plasma slab is studied using a kinetic description of the electrons based on an adiabatic invariant. The distribution function of the electrons is determined at any time and any position. Solution of the Poisson equation then enables us to determine the electric po ... [Phys. Rev. E 77, 066407 (2008)] published Mon Jun 30, 2008.
Ion acoustic vortices in quantum magnetoplasmas
Q. Haque and H. Saleem
A nonlinear equation for ion acoustic waves in dense quantum plasmas (which is analogous to the classical plasma case) has been obtained in a particular limit. Therefore it is proposed that electrostatic monopolar and dipolar vortices can appear in uniform dense quantum plasmas due to large amplitud ... [Phys. Plasmas 15, 064504 (2008)] published Mon Jun 30, 2008.
Nonlinear transport processes in tokamak plasmas. I. The collisional regimes
Giorgio Sonnino and Philippe Peeters
An application of the thermodynamic field theory (TFT) to transport processes in L-mode tokamak plasmas is presented. The nonlinear corrections to the linear (Onsager) transport coefficients in the collisional regimes are derived. A quite encouraging result is the appearance of an asymmetry between ... [Phys. Plasmas 15, 062309 (2008)] published Mon Jun 30, 2008.
Short-pulse space-charge-limited electron flows in a drift space
P. Zhang, W. S. Koh, L. K. Ang, and S. H. Chen
In this paper, the space-charge-limited (SCL) electron flows in a drift space is studied by including the effect of finite electron pulse length, which is smaller than the gap transit time. Analytical formulas are derived to calculate the maximum SCL current density that can be transported across a ... [Phys. Plasmas 15, 063105 (2008)] published Mon Jun 30, 2008.
Propagation of electron magnetohydrodynamic structures in a two-dimensional inhomogeneous plasma
Sharad Kumar Yadav, Amita Das, and Predhiman Kaw
The fully three-dimensional governing equations in the electron magnetohydrodynamic (EMHD) regime for a plasma with inhomogeneous density are obtained. These equations in the two-dimensional limit can be cast in terms of the evolution of two coupled scalar fields. The nonlinear simulations for the t ... [Phys. Plasmas 15, 062308 (2008)] published Mon Jun 30, 2008.
MeV quasi-mono-energetic proton beam created by a combination of a laser-plasma ion accelerator and synchronous rf cavity
M. Ikegami, S. Nakamura, Y. Iwashita, T. Shirai, H. Souda et al.
MeV quasi-mono-energetic proton beam is produced by a combination of a synchronous radio frequency (rf) electric field and laser-plasma ion acceleration. The experiment was carried out at the Kansai Photon Science Institute, JAEA, using the Ti:Sapphire laser system called J-KAREN. The proton beam is ... [AIP Conf. Proc. 1024, 96 (2008)] published Mon Jun 30, 2008.
Postacceleration Of Laser-Generated High Energy Protons Through Conventional Accelerator Linacs
Julien Fuchs, Patrizio Antici, Mauro Fazi, Augusto Lombardi, Mauro Migliorati et al.
The post-acceleration of laser-generated protons through conventional drift tube linear accelerators has been simulated with the particle code Parmela. The proton source is generated on the rear surface of a target irradiated by an high-intensity (10 Wcm) short-pulse (350 fs) laser and focused by a ... [AIP Conf. Proc. 1024, 90 (2008)] published Mon Jun 30, 2008.
Effects of laser prepulse on proton generation: active manipulation of the distribution of laser accelerated proton beams
D. Batani, R. Redaelli, R. Dezulian, O. Lundh, F. Lindau et al.
Laser pre-pulse is a major issue in experiments on laser-generation of protons, often limiting the performances of laser sources. In this paper, we show how we can actively use a low intensity prepulse (<10 W/cm, ns duration) to manipulate the proton beam direction or spatial energy distribution. Th ... [AIP Conf. Proc. 1024, 78 (2008)] published Mon Jun 30, 2008.
Laser-induced generation of ultraintense proton beams for high energy-density science
J. Badziak, P. Antici, J. Fuchs, S. Jablonski, A. Mancic et al.
Basic properties of high-current high-intensity ion beam generation using laser-induced skin-layer ponderomotive acceleration (SLPA) are discussed. The results of a recent experiment, in which 0.35-ps laser pulse of intensity up to 2 x 10 W/cm irradiated a thin (13 [mu]m) PS (plastic) or Au/PS targe ... [AIP Conf. Proc. 1024, 63 (2008)] published Mon Jun 30, 2008.
Notes on Laser Acceleration
T. Tajima
This note intends to motivate our effort toward the advent of new methods of particle acceleration, utilizing the fast rising laser technology. By illustrating the underlying principles in an intuitive manner and thus less jargon-clad fashion, we seek a direction in which we shall be able to properl ... [AIP Conf. Proc. 1024, 52 (2008)] published Mon Jun 30, 2008.
Radiotherapy using a laser proton accelerator
Masao Murakami, Yoshio Hishikawa, Satoshi Miyajima, Yoshiko Okazaki, Kenneth L. Sutherland et al.
Laser acceleration promises innovation in particle beam therapy of cancer where an ultra-compact accelerator system for cancer beam therapy can become affordable to a broad range of patients. This is not feasible without the introduction of a technology that is radically different from the conventio ... [AIP Conf. Proc. 1024, 275 (2008)] published Mon Jun 30, 2008.
Breakdown of Universal Intensity Scaling in Relativistic Laser-Plasma Interactions
T. J. M. Boyd and R. Ondarza-Rovira
Laser light incident on targets at intensities such that the electron dynamics is ultra-relativistic, gives rise to a harmonic spectrum extending to high orders and characterized by relatively slow decay with harmonic number. The decay with harmonic number m follows a power law dependence m and argu ... [AIP Conf. Proc. 1024, 233 (2008)] published Mon Jun 30, 2008.
Propagation of lambda[sup 3] Laser Pulses in Underdense Plasma
Alexei Zhidkov, Koshichi Nemoto, Takuya Nayuki, Yuji Oishi, and Takashi Fujii
We study the interaction of lambda laser pulses with underdense plasma by means of real geometry particle-in-cell simulation. Underdense plasma irradiated by even low energy lambda laser pulses can be an efficient source of multi-MeV electrons, ~50 nC/J. The electron acceleration driven by low energ ... [AIP Conf. Proc. 1024, 223 (2008)] published Mon Jun 30, 2008.
High energy electron acceleration with PW-class laser system
N. Nakanii, K. Kondo, Y. Mori, E. Miura, T. Yabuuchi et al.
We performed electron acceleration experiment with PW-class laser and a plasma tube, which was created by imploding a hollow polystyrene cylinder. In this experiment, electron energies in excess of 600 MeV have been observed. Moreover, the spectra of a comparatively high-density plasma ~10 cm had a ... [AIP Conf. Proc. 1024, 215 (2008)] published Mon Jun 30, 2008.
Stable High-Quality Electron Bunch Generation via Counter-Crossing Injection
H. Kotaki, I. Daito, M. Kando, Y. Hayashi, J. Ma et al.
We demonstrate a highly reproducible acceleration of a high-quality electron bunch injected into the laser wake field accelerator with the help of a counter-crossing laser pulse. In our experiments, the wake field is generated by a sub-relativistic laser pulse; the second laser pulse collides with t ... [AIP Conf. Proc. 1024, 208 (2008)] published Mon Jun 30, 2008.
Opportunities for TeV Laser Acceleration
M. Kando, H. Kiriyama, J. K. Koga, S. Bulanov, A. W. Chao et al.
A set of ballpark parameters for laser, plasma, and accelerator technologies that define for electron energies reaching as high as TeV are identified. These ballpark parameters are carved out from the fundamental scaling laws that govern laser acceleration, theoretically suggested and experimentally ... [AIP Conf. Proc. 1024, 197 (2008)] published Mon Jun 30, 2008.
Prospects for ultrafast lasers in ion-radiography
P. V. Nickles, M. Schnurer, S. Steinke, T. Sokollik, S. Ter-Avetisyan et al.
We demonstrate the feasibility of field mapping with proton beams having kinetic energies between 12 Megaelectronvolt. Adjustment of the ultrafast (40 fs) laser driven TNSA mechanism delivers a nearly pure proton beam with a low transversal emittance and an emerging broad kinetic spectrum. Suitable ... [AIP Conf. Proc. 1024, 183 (2008)] published Mon Jun 30, 2008.
Laser driven MeV proton beam focussing by auto-charged electrostatic lens configuration
S. Kar, K. Markey, P. T. Simpson, C. Bellei, J. S. Green et al.
Significant reduction of inherent large divergence of the laser driven MeV proton beams is achieved by strong (of the order of 10 V/m) electrostatic focussing field generated in the confined region of a suitably shaped structure attached to the proton generating foil. The scheme exploits the positiv ... [AIP Conf. Proc. 1024, 173 (2008)] published Mon Jun 30, 2008.
Development of Laser-Driven Proton and Electron Sources Using APRI 100-TW Ti:Sapphire Laser System
I. W. Choi, N. Hafz, T. M. Jeong, H. T. Kim, C. M. Kim et al.
At the Advanced Photonics Research Institute (APRI) in Korea, we have a Ti:sapphire laser system which delivers laser pulses of 100-TW peak power and 32-fs pulse duration at the repetition rate of 10 Hz. This laser facility is being used to develop compact laser-driven proton and electron sources. E ... [AIP Conf. Proc. 1024, 165 (2008)] published Mon Jun 30, 2008.
Laser ion acceleration by a near-critical density target
A. Yogo, H. Daido, S. V. Bulanov, T. Zh. Esirkepov, K. Nemoto et al.
Protons having energies up to 3.8 MeV are experimentally generated by the p-polarized, 45 fs, ~10 W/cm laser pulse interacting with a near-critical plasma cloud produced by the irradiation of the amplified spontaneous emission (ASE) pedestal at an intensity of ~10 W/cm onto a 7.5-[mu]m-thick polyimi ... [AIP Conf. Proc. 1024, 157 (2008)] published Mon Jun 30, 2008.
High-energy proton generation from thin-foil targets with a high-intensity ultra-short pulse laser
Akito Sagisaka, Hiroyuki Daido, Akifumi Yogo, Koichi Ogura, Satoshi Orimo et al.
We observe the proton signals with thin-foil polyimide and copper targets with a high-intensity Ti:sapphire laser pulse. High-energy protons with the maximum energy of 2.3 MeV for 7.5 [mu]m thick polyimide target and 1.2 MeV for 3 [mu]m thick copper target are generated at the laser intensity of ~1 ... [AIP Conf. Proc. 1024, 151 (2008)] published Mon Jun 30, 2008.
Femtosecond laser driven high-flux highly collimated MeV-proton beam
M. Nishiuchi, H. Daido, A. Yogo, S. Orimo, K. Ogura et al.
Highlly collimated energetic protons whose energies are up to 4 MeV are generated by an intense femtosecond Titanium Sappheire laser pulse interacting with a 7.5, 12.5, and 25 [mu]m-thick Polyimide tape target and 5 [mu]m-thick copper target. We find no clear difference on the proton spectra from 7. ... [AIP Conf. Proc. 1024, 137 (2008)] published Mon Jun 30, 2008.
Plasma expansion into vacuum with charge separation effect
Masakatsu Murakami
Plasma expansion into vacuum and resultant ion acceleration are studied theoretically. A new self-similar solution is found to describe free expansion of a finite plasma mass into vacuum with a full account of charge separation effects. It is argued that the normalized plasma size Lambda = R/lambda ... [AIP Conf. Proc. 1024, 125 (2008)] published Mon Jun 30, 2008.
Proton acceleration by oblique laser pulse incidence on a double-layer target
T. Morita, T. Zh. Esirkepov, S. V. Bulanov, J. Koga, and M. Yamagiwa
We investigate high quality laser proton acceleration with three dimensional particle-in-cell simulations for oblique incidence of the laser pulse on a double-layer target. The double-layer target is composed of a high-Z ion layer coated by a thin and narrow hydrogen patch. The highest proton energy ... [AIP Conf. Proc. 1024, 114 (2008)] published Mon Jun 30, 2008.
PIC Simulations Of Ion Acceleration By Linearly And Circularly Polarized Laser Pulses
Jiri Limpouch, Ondrej Klimo, Jan Psikal, Vladimir T. Tikhonchuk, Shigeo Kawata et al.
Linearly polarized laser radiation accelerates electrons to very high velocities and these electron form a sheath layer on the rear side of thin targets where preferentially protons are accelerated. When mass-limited targets are used, the lateral transport of the absorbed laser energy is reduced and ... [AIP Conf. Proc. 1024, 104 (2008)] published Mon Jun 30, 2008.
Effect of preplasma on energetic electron and ion generation by irradiation of ultra-intense laser pulses
Tatsufumi Nakamura, Hideo Nagatomo, and Kunioki Mima
In the interactions of ultra-intense laser pulses with solid targets, a preformed plasma is generated in front of the target by laser prepulse before the main pulse irradiates the target. The characteristics of the electrons generated by laser-plasma interaction depend on the distribution of preplas ... [AIP Conf. Proc. 1024, 31 (2008)] published Mon Jun 30, 2008.
Asymptotically self-similar propagation of the spherical ionization waves. (arXiv:0806.3189v2 [physics.plasm-ph] UPDATED)
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