Laser uniformity and hydrodynamic stability experiments 
at the OMEGA laser facility

Experiments to demonstrate the effects of various beam-smoothing techniques have been performed on the 60-beam, 30-kJ UV OMEGA laser system. These include direct measurements of the effect beam-smoothing techniques have on laser beam nonuniformity and on both planar and spherical targets. Demonstrated techniques include polarization smoothing and “dual-tripler” third-harmonic generation required for future broad bandwidth (∼1 THz) smoothing by spectral dispersion (SSD). The effects of improvements in single-beam uniformity are clearly seen in the target-physics experiments, which also show the effect of the laser pulse shape on the efficacy of SSD smoothing. Saturation of the Rayleigh-Taylor (RT) growth of the broad-bandwidth features, in agreement with the Haan model (Haan, 1989), produced by laser imprinting has also been observed.

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Plastic plasma as a compressor of aluminum plasma at the PALS experiment

Laser and Particle Beams ◽

10.1017/s0263034611000528 ◽

2011 ◽

Vol 30 (1) ◽

pp. 1-7 ◽

Cited By ~ 8

Author(s):

A. Kasperczuk ◽

T. Pisarczyk ◽

T. Chodukowski ◽

Z. Kalinowska ◽

S.Yu. Gus'kov ◽

...

Keyword(s):

Focal Spot ◽

Laser System ◽

Target Material ◽

Plasma Pressure ◽

Plasma Stream ◽

Harmonic Frequency ◽

Third Harmonic ◽

X Ray ◽

Laser Facility ◽

Aluminum Plasma

AbstractIn our earlier papers, we demonstrated that plasma pressure decreases with the growing atomic number of the target material. That experimentally confirmed fact brought about a question whether it would be possible to collimate the Al plasma outflow by using plastic plasma as a compressor. To prove that idea we used in our next experiments a plastic target with an Al cylindrical insert of 400 µm in diameter. The measurements were carried out at the Prague Asterix Laser System iodine laser facility. The laser provided a 250 ps (full width at half maximum (FWHM)) pulse with energy of 130 J at the third harmonic frequency (λ3 = 0.438 µm). The focal spot diameters (ΦL) 800, 1000, and 1200 µm ensured predominance of the plastic plasma amount high enough for the effective Al plasma compression. To study the Al plasma stream propagation and its interaction with plastic plasma a three-frame interferometric system and an X-ray camera were used. The experiment provided a proof that creation of the collimated Al plasma jet by action of outer plastic plasma is feasible. In order to discuss of the experimental results a thorough theoretical analysis was carried out.

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Hohlraum-Driven High-Convergence Implosion Experiments with Multiple Beam Cones on the Omega Laser Facility

Physical Review Letters ◽

10.1103/physrevlett.89.165001 ◽

2002 ◽

Vol 89 (16) ◽

Cited By ~ 29

Author(s):

Peter Amendt ◽

R. E. Turner ◽

O. L. Landen

Keyword(s):

Multiple Beam ◽

Laser Facility ◽

Omega Laser

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Hohlraum-Driven Mid-Z(SiO2) Double-Shell Implosions on the Omega Laser Facility and Their Scaling to NIF

Physical Review Letters ◽

10.1103/physrevlett.103.145003 ◽

2009 ◽

Vol 103 (14) ◽

Cited By ~ 14

Author(s):

H. F. Robey ◽

P. A. Amendt ◽

J. L. Milovich ◽

H.-S. Park ◽

A. V. Hamza ◽

...

Keyword(s):

Laser Facility ◽

Omega Laser

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Implementation of a Faraday rotation diagnostic at the OMEGA laser facility

High Power Laser Science and Engineering ◽

10.1017/hpl.2018.42 ◽

2018 ◽

Vol 6 ◽

Author(s):

A. Rigby ◽

J. Katz ◽

A. F. A. Bott ◽

T. G. White ◽

P. Tzeferacos ◽

...

Keyword(s):

Magnetic Field ◽

Magnetic Fields ◽

Faraday Rotation ◽

Field Measurements ◽

Thomson Scattering ◽

Proton Radiography ◽

Time Resolved ◽

Rotation Measurement ◽

Laser Facility ◽

Omega Laser

Magnetic field measurements in turbulent plasmas are often difficult to perform. Here we show that for ${\geqslant}$kG magnetic fields, a time-resolved Faraday rotation measurement can be made at the OMEGA laser facility. This diagnostic has been implemented using the Thomson scattering probe beam and the resultant path-integrated magnetic field has been compared with that of proton radiography. Accurate measurement of magnetic fields is essential for satisfying the scientific goals of many current laser–plasma experiments.

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Interferometric investigations of influence of target irradiation on the parameters of laser-produced plasma jets

Laser and Particle Beams ◽

10.1017/s0263034607000547 ◽

2007 ◽

Vol 25 (3) ◽

pp. 425-433 ◽

Cited By ~ 13

Author(s):

A. Kasperczuk ◽

T. Pisarczyk ◽

S. Borodziuk ◽

J. Ullschmied ◽

E. Krousky ◽

...

Keyword(s):

Focal Spot ◽

Laser Energy ◽

Plasma Jet ◽

Plasma Jets ◽

Plasma Expansion ◽

Third Harmonic ◽

Fundamental Process ◽

Laser Produced Plasma ◽

Laser Facility ◽

Planar Target

Our recent experimental results demonstrate that the formation of plasma jets is a fundamental process accompanying the laser produced plasma expansion, if a massive planar target with relatively high atomic number is irradiated by a defocused laser beam. In this paper some new results on the influence of target irradiation conditions on plasma jet parameters are presented. The experiment was carried out at the PALS iodine laser facility, with the third harmonic beam of the pulse duration of 250 ps (FWHM). The beam energies varied in the range of 13–160 J, the focal spot radii in the range of 35–600 µm. The planar massive targets used in the experiment were made of Cu, Ag and Ta. For measurements of the electron density evolution a three frame interferometric system was employed. The jets were observed in the whole range of the laser energy used. The initial velocities of the plasma jets produced in the reported experiment reached the value of up to 7·107 cm/s, the jets were up to 4 mm long including the jet pedestal and about 400 µm in diameter. Calculations of the efficiency of the plasma jet production show that it decreases with increasing the laser energy.

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