scholarly journals Generation of hot and dense plasmas in laser accelerated colliding foil systems

1998 ◽  
Vol 16 (1) ◽  
pp. 21-30 ◽  
Author(s):  
P. Angelo ◽  
H. Derfoul ◽  
P. Gauthier ◽  
P. Sauvan ◽  
A. Poquerusse ◽  
...  
Keyword(s):  
Thermal Conduction ◽  
Focal Spot ◽  
Laser Intensity ◽  
Dense Plasma ◽  
Lateral Expansion ◽  
Dense Plasmas ◽  
Monochromatic Imaging ◽  
Thin Foils ◽  
Plasma Effects ◽  
Good Agreement

We create hot (Te > 200 eV) and dense (Ne > 1023 cm−3) plasmas in the colliding zone of two thin foils accelerated by two laser beams of the LULI facilities. Three spectroscopic diagnostics (two 1D space-resolved spectrographs and a 2D monochromatic imaging) are used to drive the efficiency of the compression. We show that 2D effects are important. Realistic simulations of these experiments must be done, taking into account the inhomogeneity of the laser intensity in the focal spot, the foil distorsion, the plasma lateral expansion, and the lateral thermal conduction. Two-dimensional LASNEX code results are in good agreement with our experimental results. The optimized compressed plasmas generated are favorable for the exhibition of dense plasma effects due to molecular formations, and they reproduce in laboratory some astrophysical situations.

scholarly journals Experimental study of picosecond laser plasma formation in thin foils

2000 ◽  
Vol 18 (1) ◽  
pp. 145-150 ◽  
Author(s):  
M. GALIMBERTI ◽  
L.A. GIZZI ◽  
A. BARBINI ◽  
P. CHESSA ◽  
A. GIULIETTI ◽  
...  
Keyword(s):  
Laser Pulse ◽  
High Performance ◽  
Focal Spot ◽  
Laser System ◽  
Picosecond Laser ◽  
Plasma Formation ◽  
Numerical Code ◽  
Passive Component ◽  
Thin Foils ◽  
Good Agreement

A high performance, fully controlled picosecond laser system has been designed and built with the aid of a numerical code capable of simulating the temporal behavior of the laser system, including each active and passive component. The laser performance was characterized with an optical streak camera, equivalent plane monitor, and calorimeter measurements. The laser pulse was focused on 150-nm thick foils to investigate plasma formation and the related transmittivity of the laser light. The experimental data are in very good agreement with the predictions of a simple, 2D analytical model that takes into account the actual shot-to-shot features of the laser pulse. The temporal profile of the pulse and the intensity distribution in the focal spot were found to play a key role in determining the transmission properties of the laser-irradiated foil. This work may be relevant to a wide class of laser exploded foil plasma experiments.

scholarly journals Improvements to ion-correlation experiments in dense plasmas

1992 ◽  
Vol 10 (1) ◽  
pp. 41-51 ◽  
Author(s):  
B. A. Shiwai ◽  
A. Djaoui ◽  
T. A. Hall ◽  
G. J. Tallents ◽  
S. J. Rose
Keyword(s):  
Good Accuracy ◽  
Dense Plasma ◽  
Coupling Parameter ◽  
Correlation Effects ◽  
X Ray ◽  
Dense Plasmas ◽  
Solid Density ◽  
X Ray Absorption ◽  
Good Agreement

Improved measurements of ion-correlation effects in a dense shock-compressed plasma are presented. The extended X-ray-absorption fine-structure (EXAFS) technique on the aluminum K edge is used to observe the short-range order within a dense plasma. Densities of about three times solid density were measured with good accuracy. The experimental measurements of density give results that are in good agreement with the MEDUSA onedimensional fluid code predictions. The improved quality of the data enabled us to calculate the ion coupling parameter during the compression and the subsequent heating of the plasma. An estimation of the temperature is given on the basis of published models, and an approximate agreement is obtained with the MEDUSA code predictions.

scholarly journals High Resolution Lithium Like Satellites to the IS2IS0 – ls 3p 1P1 Line in Laser-Produced Dense Plasmas

1984 ◽  
Vol 86 ◽  
pp. 246-246
Author(s):  
P. Audebert ◽  
J.P. Geindre ◽  
J.C. Gauthier ◽  
Ph. Alaterre ◽  
C. Popovics ◽  
...  
Keyword(s):  
High Resolution ◽  
Dense Plasma ◽  
Laser Irradiance ◽  
Electron Densities ◽  
Equilibrium Conditions ◽  
Laser Target ◽  
Dense Plasmas ◽  
Dielectronic Satellite ◽  
Good Agreement

The dielectronic satellite lines from the ls21a 3lb and ls31a 31b, double-excited configurations of lithium-like ions have been studied experimentally and theoretically under dense-plasma conditions. Good agreement between theory and measurements performed in laser-target interactions at 0.53 m wavelength, 1014 W/cm2 laser irradiance show that collisional equilibrium conditions are reached between n − 3 singly and double excited levels at electron densities greater than 1022 cm−3 in Al and Si.

The application of intense ion beams to the creation of hot dense plasmas

1981 ◽  
Vol 300 (1456) ◽  
pp. 613-621 ◽  
Keyword(s):  
Heavy Ions ◽  
Dense Plasma ◽  
Ion Beams ◽  
Current Understanding ◽  
Dense Plasmas ◽  
Current Thinking ◽  
Ion Energies ◽  
Light Ions ◽  
Small Targets ◽  
Thermonuclear Ignition

A broad review is presented of the physics central to the production of hot dense plasmas by intense ion beams. Particular attention is paid to the reasons for using ion beams rather than lasers. By using simple laws the required beam intensities and ion energies for light ions (protons, deuterons, etc.) and heavy ions ( A > 120) are compared. Current understanding of ion-dense plasma interactions is discussed together with current thinking on possible accelerator sources of intense beams and their final transport to small targets. Emphasis is placed throughout on the use of ion beams for heating targets of deuterium-tritium mixtures to thermonuclear ignition.

scholarly journals Excitation of ion wakefields by electromagnetic pulses in dense plasmas

2009 ◽  
Vol 75 (1) ◽  
pp. 15-18 ◽  
Author(s):  
P. K. SHUKLA
Keyword(s):  
Wave Equation ◽  
Electromagnetic Wave ◽  
Electromagnetic Waves ◽  
Electromagnetic Pulse ◽  
Dense Plasma ◽  
Ponderomotive Force ◽  
Electromagnetic Pulses ◽  
Dense Plasmas ◽  
High Energies

AbstractThe excitation of electrostatic ion wakefields by electromagnetic pulses in a very dense plasma is considered. For this purpose, a wave equation for the ion wakefield in the presence of the ponderomotive force of the electromagnetic waves is obtained. Choosing a typical profile for the electromagnetic pulse, the form of the ion wakefields is deduced. The electromagnetic wave-generated ion wakefields can trap protons and accelerate them to high energies in dense plasmas.

scholarly journals Diagnostic potential of advanced X-ray spectroscopy for investigation of hot dense plasmas

2004 ◽  
Vol 22 (1) ◽  
pp. 25-28 ◽  
Author(s):  
O. RENNER ◽  
I. USCHMANN ◽  
E. FÖRSTER
Keyword(s):  
Dense Plasma ◽  
X Ray ◽  
Dense Plasmas ◽  
Plasma Diagnosis ◽  
Bent Crystal ◽  
Complex Information ◽  
Diagnostic Potential ◽  
Vertical Dispersion ◽  
Fundamental Research

Modern experimental methods and instruments for X-ray spectral investigation of hot dense plasma provide complex information on environmental conditions in extreme states of matter. The basic spectroscopic conceptions for K-shell plasma diagnosis are outlined, the main characteristics of toroidally bent crystal spectrometers and vertical-dispersion instruments are briefly reviewed. Selected applications (monitoring and optimization of the emission from the femtosecond-laser-produced plasmas, characterization of colliding laser-exploded foils, spectral line merging, and continuum lowering in constrained-flow plasmas) demonstrate the usefulness of advanced spectroscopic methods for plasma diagnostics and fundamental research.

Compressive Stiffness Verification of Stirrup Rubber Bearing

2004 ◽  
Author(s):  
Bo-Jen Chen ◽  
C. S. Tsai ◽  
Tsu-Cheng Chiang
Keyword(s):  
Axial Load ◽  
Horizontal Plane ◽  
Steel Plates ◽  
Computational Results ◽  
Lateral Expansion ◽  
Pressure Function ◽  
Rubber Bearing ◽  
Compression Stiffness ◽  
Bearing System ◽  
Good Agreement

In recent years, there has been an immense amount of interest in utilizing the rubber bearing system as a practical approach to seismic-resistant design. The stirrup rubber bearing is confined and bonded by stirrup equipments so as to restrict the lateral expansion of the rubbers due to axial load and increase the compression stiffness. Based on two kinematics assumptions that the horizontal plane parallel to the stirrup equipments or rigid bounding steel plates remains plane and the vertical lines become parabolic after loading, the pressure function and compression stiffness for the stirrup rubber bearing are derived. A good agreement between experimental results by the component tests and computational results by the proposed formulae has been obtained.

Hydrogen spectral lines with the inclusion of dense-plasma effects

1991 ◽  
Vol 44 (10) ◽  
pp. 6834-6844 ◽  
Author(s):  
S. Günter ◽  
L. Hitzschke ◽  
G. Röpke
Keyword(s):  
Dense Plasma ◽  
Spectral Lines ◽  
Plasma Effects

Wave functions for the hydrogen atom in a dense plasma

2003 ◽  
Vol 81 (11) ◽  
pp. 1243-1248 ◽  
Author(s):  
Y P Varshni
Keyword(s):  
Hydrogen Atom ◽  
Dense Plasma ◽  
Wave Functions ◽  
Electron Interaction ◽  
Dipole Polarizability ◽  
Variational Wave Functions ◽  
Absorption Oscillator Strength ◽  
Variational Wave ◽  
Good Agreement ◽  
03.65 Ge

A hydrogen atom in a high-density plasma is simulated by a model in which the hydrogen atom is confined in an impenetrable spherical box, with the atom at the centre. For the proton–electron interaction the Debye–Huckel potential is used. Variational wave functions are proposed for the 1s and 2p states. Energies calculated from these for different values of the radius of box (r0) are shown to be in good agreement with the exact values. The variational wave functions are further employed to calculate the absorption oscillator strength for the 1s [Formula: see text] 2p transition and the dipole polarizability for different values of r0. PACS Nos.: 03.65.Ge, 32.70.Os, 31.70.Dk, 52.20.–j

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