Numerical Calculations of Plasma Heating by Means of Subnanosecond Laser Pulses

Abstract The influence of light pressure on plane and spherical plasma flows is treated. Numerical calculations show that smooth laser pulses lead to formation of an overdense plateau if thermal transport is non-negligible there, and that an originally supersonic flow becomes subsonic in this region. The results are consistent with analytical considerations. Density humps, as reported in the literature, are found in conjunction with spiking pulses or prepulses only.

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FIELD-FREE MOLECULAR ORIENTATION IN DISSIPATIVE MEDIA BY A COMBINATION OF FEMTOSECOND AND THz LASER PULSES

Journal of Theoretical and Computational Chemistry ◽

10.1142/s0219633613500065 ◽

2013 ◽

Vol 12 (03) ◽

pp. 1350006 ◽

Cited By ~ 1

Author(s):

YONG LIU ◽

JIAN LI ◽

JIE YU ◽

SHU-LIN CONG

Keyword(s):

Liouville Equation ◽

Delay Time ◽

Molecular Orientation ◽

Laser Pulses ◽

Numerical Calculations ◽

Orientation Degree ◽

Carrier Envelope Phase ◽

Theoretical Scheme ◽

Dissipative Media ◽

Dissipative Environment

We present a theoretical scheme for achieving the field-free molecular orientation in dissipative media by a combination of femtosecond and THz laser pulses. Numerical calculations are performed by solving the quantum Liouville equation based on multilevel Bloch model. The molecular orientation degree is sensitive to the carrier-envelope phase of the THz pulse and the delay time between the two pulses. The orientation and the rotational population of CO molecules in dissipative environment are computed at different pressures and temperatures. The influence of pure decoherence on the molecular orientation is also discussed.

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Absorption of ultrashort laser pulses in solid targets

Laser and Particle Beams ◽

10.1017/s0263034600003499 ◽

1991 ◽

Vol 9 (2) ◽

pp. 465-475 ◽

Cited By ~ 12

Author(s):

F. Cornolti ◽

P. Mulser ◽

M. Hahn

Keyword(s):

Laser Light ◽

Plasma Heating ◽

Normal Incidence ◽

Laser Pulses ◽

Femtosecond Laser Pulses ◽

Plasma Formation ◽

Ultrashort Laser Pulses ◽

Heating Process ◽

Strong Electron ◽

Collisional Ionization

Femtosecond laser pulses are capable of producing very high light intensities at moderate pulse energies. We study the laser light absorption at flux densities of 1017 W/cm2 and higher during the plasma formation and the plasma heating process. In the first stage multiphoton and collisional ionization dominate. Modification of the inverse bremsstrahlung absorption occur owing to ionization dephasing. In the second stage beam energy conversion is mainly by collisional absorption at normal incidence, and by resonance absorption at oblique illumination. Simultaneously strong electron heat conduction provides for plasma formation and heating in deeper layers of the solid not accessible to the laser light. The penetration depth of the laser beam is modified by the anomalous skin effect. The electron-ion collision frequency at the high laser intensities under consideration is determined by the oscillation energy of the electrons rather than by their thermal motion. Although it reaches high values (1014-1016 S-1), all kinds of solid targets become strongly reflecting (>60%) owing to the formation of electron densities largely exceeding those of solid-state plasmas. Effects modifying the degree of absorption are briefly discussed.

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X-ray gain at 18·2 nm (CVI Balmer α) in laser-produced recombining carbon plasmas

Laser and Particle Beams ◽

10.1017/s0263034600005565 ◽

1988 ◽

Vol 6 (3) ◽

pp. 621-624 ◽

Cited By ~ 1

Author(s):

W. Brunner ◽

R. John ◽

Th. Schlegel

Keyword(s):

Plasma Heating ◽

Laser Pulses ◽

X Ray ◽

Short Laser Pulses ◽

Experimental Findings ◽

Theoretical Results

Plasma heating by short laser pulses is investigated theoretically. Gain coefficients of 3… 4 cm−1 at the Balmer α transition in carbon could be obtained. The theoretical results agree with the corresponding experimental findings.

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Plasma heating by CO 2 -laser pulses for efficient multi-charged ion generation

10.1117/12.536893 ◽

2003 ◽

Author(s):

Konstantin N. Makarov ◽

Dmitri D. Maluta ◽

Vitali C. Roerich ◽

Yuri A. Satov ◽

Yuri B. Smakovskii ◽

...

Keyword(s):

Plasma Heating ◽

Laser Pulses ◽

Ion Generation

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Plasma heating with very short laser pulses

Physics Letters A ◽

10.1016/0375-9601(72)90132-6 ◽

1972 ◽

Vol 38 (5) ◽

pp. 303-304

Author(s):

B.A. Demidov ◽

S.D. Fanchenko ◽

G.V. Sholin ◽

S.D. Zakharov ◽

P.G. Kriukov

Keyword(s):

Plasma Heating ◽

Laser Pulses ◽

Short Laser Pulses

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Generation of Terahertz Radiation by Two-Color Ionizing Laser Pulses with Arbitrary Intensity Ratios

Photonics ◽

10.3390/photonics7020038 ◽

2020 ◽

Vol 7 (2) ◽

pp. 38

Author(s):

Ivan Laryushin

Keyword(s):

Terahertz Radiation ◽

Laser Pulses ◽

Numerical Calculations ◽

Analytical Formulas ◽

Optimal Intensity ◽

Intensity Ratios ◽

Frequency Ratios ◽

Arbitrary Intensity ◽

Color Components

The dependence of the terahertz energy generated by two-color femtosecond ionizing pulses on intensities of both one-color components is studied. The numerical calculations are supported with analytical formulas which help to reveal the nature of these dependences. The optimal intensity ratios in the cases when the frequency ratios in two-color pulse are equal to 2, 3/2 and 4 are found.

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