Fyzikální ústav Akademie věd ČR

Selected results of department 51

Results originated at the Prague Asterix Laser System (PALS)

The most important results of the department members and related to the PALS, which is led by Ing. K. Jungwirth, DrSc., were published and summarized in the following annual lists [1-5].

Other results supported by PALS research programs, donated by Czech Ministry of Education, Youth, and Sports, and by European Commission, and by an enormous assignment of many department members under leadership of Ing. K. Jungwirth, DrSc., were also published [6-10] by scientists from other departments or institutes, particularly universities.

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Experimental studies of generation of similar to 100 MeV Au-ions from the laser-produced plasma

Using the PALS iodine laser system, Au ions with the charge state up to 58+ and with the kinetic energy as high as ~300 MeV were generated. The production of these ions was tested in dependence on the laser frequency (1ω, 3ω), on the irradiation/detection angles (0°, 30°), on the focus position with regard to the target surface, and on the target thickness (500 µm, 200 µm, 80 µm).  The full text >>

Angular distributions of ions emitted from laser plasma produced at various irradiation angles and laser intensities

Angular distributions of currents and velocities (energies) of ions produced at various target irradiation angles and laser intensities ranged from 1010 W/cm2 to 1017 W/cm2 were analyzed. It was confirmed that for low laser intensities the ion current distributions are always peaked along the target normal.  The full text >>

Repetitive outbursts of fast carbon and fluorine ions from sub-nanosecond laser-produced plasma

Repeated plasma outbursts were recognized at our analyzing currents of the fast carbon and fluorine ions produced with the sub-nanosecond PALS laser beam focused onto polytetrafluoroethylene and polyethylene targets. The deconvolution of ion collector signal made the determination of the ion temperature as well as the effective voltage accelerating the fast ions possible. The value of the accelerating voltage decreases with increasing ion outburst number; the highest value of this voltage was about 800 kV.

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Investigations of plasma jet interaction with ambient gases by multi-frame interferometric and X-ray pinhole camera systems

Interactions of laser driven plasma jets with He and Ar gas puffs was investigated experimentally by means of three-frame interferometric/shadowgraphic system and three-frame X-ray pinhole camera. A defocused iodine laser beam using the Prague Asterix Laser System (PALS) interacting with massive planar Cu targets generated high-speed well-collimated plasma jets.  The full text >>

PALS laser energy transfer into solid targets and its dependence on the lens focal point position with respect to the target surface

This result is devoted to investigations of laser energy transfer into solid targets with respect to the focusing lens focal point position relative to the solid target surface as obtained at the PALS laser facility. The third harmonic of the PALS laser beam with energy ~90 J and pulse duration ~250 ps (FWHM) was used for irradiation of two kinds of targets made of Cu: a slab and a 3.6 µm thick foil. The focal point of the beam was located either inside or in front of the target surface, and care was taken to ensure the same laser spot radii in both cases (250 µm).  The full text >>

Experimental and theoretical investigations of mechanisms responsible for plasma jets formation at PALS

Recent experimental results demonstrated that well formed plasma jets can be produced at laser interaction with targets made of materials with high atomic number (A ≥ 29 where A = 29 corresponds to Cu). On the contrary, it is impossible to launch a plasma jet on low-A material targets like plastic.  The full text >>

Hybrid laser

Iodine photodissociation laser SOFIA

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Two-dimensional-imaging spectrograph

A minute, yet practical, modification of a well-known spectrograph based on a set of wedged narrow band filters is presented. It makes possible two-dimensional-imaging spectral measurements with a potential subpixel precision of a few micrometers. The simple spectroscopic device can evaluate dispersion of quantities which can be transformed into an image, e.g., into a spatial beam distribution. The spectrograph was used to measure angular dispersion of both a laser oscillator producing femtosecond pulses and a simple dispersive optical system, an optical wedge.

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