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Femtosekundowa polar-interferometria jako nowa diagnostyka w badaniach w eksperymencie PALS (Prague Asterix Laser System) cz. 1

Pisarczyk T.

Przegląd Techniczny : Gazeta Inżynierska

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2016

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nr 4

15--22

PL

W artykule przedstawione są najnowsze osiągnięcia badań przeprowadzanych w eksperymencie laserowym PALS w Pradze (Prague Asterix Laser System) zrealizowanych przez zespół prof. dr. hab. Tadeusza Pisarczyka z Instytutu Fizyki i Laserowej Mikrosyntezy w Warszawie. W badaniach tych jako nowa efektywna diagnostyka wykorzystywana jest femtosekundowa polaro-interferometria, która została zaimplementowana dzięki zastosowaniu do oświetlenia układów diagnostycznych: 3-kadrowego interferometru i 2-kanałowego polar-interferometru, femtosekundowego lasera Ti:Sa o szerokości impulsu ok. 40 fs. Przedstawiono wybrane wyniki badań ilustrujące użyteczność femtosekundowej polaro-interferometrii w badaniach na PALS dotyczących: (i) udarowego zapłonu fuzji laserowej, (ii) nowej metody wytwarzania plazmy fotojonizacyjnej dla badań astrofizycznych oraz (iii) generacji wysokoenergetycznych jonów do zastosowań medycznych i radiografii.

EN

In the article the latest achievements of researches in the PALS experiment in Prague (Prague Asterix Laser System) carried out by a team of professor Tadeusz Pisarczyk from the Institute of Plasma Physics and Laser Microfusion in Warsaw are presented. In these studies, the femtosecond polaro-interferometry, as a new effective diagnostic is used, and which has been implemented thanks to irradiation diagnostic systems: 3-frame interferometer and 2-channel polaro-imterferometer by the Ti:Sa femtosecond diagnostic laser having a pulse duration of about 40 fs. The selected results are presented, which the usefulness of the femtosecond polaro-interferometry demonstrate for the studies on PALS connected with: (i) the shock ignition concept of the inertial fusion, (ii) the new method of the photoionized plasma creation for astrophysical researches and (iii) generation of high-energy ions for the medical and the radiography applications.

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Femtosekundowa polar-interferometria jako nowa diagnostyka w badaniach w eksperymencie PALS (Prague Asterix Laser System) cz. 2

Pisarczyk T.

Przegląd Techniczny : Gazeta Inżynierska

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2016

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nr 5

23--26

3

Interferometry of the plasma focus equipped with forehead cathode

Kubeš P., Klír D., Rezac K., Paduch M., Pisarczyk T., Scholz M., Chodukowski T., Kalinowska Z., Hitschfel J., Kortanek J., Kravárik J., Ivanova-Stanik I., Bienkowska B., Karpinski L., Zielinska E., Sadowski M. J., Tomaszewski K.

Nukleonika

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2012

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Vol. 57, No. 2

189-192

EN

The PF-1000 plasma-focus facility in Warsaw, equipped with Mather-type coaxial electrodes working with a deuterium filling, was modified by the addition of a cathode disk in front of the anode front-plate at a distance of 3 cm. The plasma was diagnosed with temporal resolved interferometry and neutron diagnostics. The modified electrode configuration showed an increase of the current in the pinch phase and a decrease of the total neutron yield. The lower total neutron yield is caused by a lower energy of deuterons producing the observed neutrons and by a decrease of the velocity of transformations of the structures in the pinch column.

4

Plasma jet generation by flyer disk collision with massive target

Kasperczuk A., Pisarczyk T., Borodziuk S., Gus'kov S. Y., Ullschmied J., Krousky E., Masek K., Pfeifer M., Rohlena K., Skala J., Kalal M., Limpouch J., Pisarczyk P.

Optica Applicata

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2007

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Vol. 37, nr 1-2

73-82

EN

In this paper, results from experiments with Al flyer targets (disks with a diameter of 300 mm and a thickness of 6 mm) accelerated at first to high velocities by PALS iodine laser pulses (with an energy of 130 J, pulse duration of 400 ps, a wavelength of 1.315 mm, and laser spot diameter of 250 mm), subsequently creating craters after their collisions with massive Al targets (placed at a distance of the order of 200 mm) are presented. To measure the plasma density evolution a three frame interferometric system was employed. The experimental results demonstrate that the flyer disk-massive target collision generates an axial plasma jet corresponding to a flat shock wave propagating in a massive target. This form of the shock wave was deduced from a crater trapezoidal shape which was reconstructed by means of crater replica technique.

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High power laser interaction with single and double layer targets

Borodziuk S., Demchenko N. N., Guskov S. Y., Jungwirth K., Kalal M., Kasperczuk A., Kondrashov V. N., Kralikova B., Krousky E., Limpouch J., Masek K., Pisarczyk P., Pisarczyk T., Pfeifer M., Rohlena K., Rozanov V.B., Skala J., Ullschmied J.

Optica Applicata

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2005

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Vol. 35, nr 2

241-262

EN

Results of extended complementary experimental and computer simulation studies of craters formation produced by high power lasers in single and double layer targets are presented. The experimental investigation was carried out using the PALS (Prague Asterix Laser System) facility working with two different laser beam wavelengths: L(lambda)1 = 1.315 žm and L3 = 0.438 žm. Two types of targets made of Al were used: single massive targets and double targets consisting of foils or disks (6 and 11 žm thick for both cases) placed in front of the massive target at distances of 200 and 500 žm. The targets were illuminated by laser energies EL= 130, 240 and 390 J always focused with diameter of 250 žm. In all experiments performed the laser pulse duration was equal to 400 ps. The 3-frame interferometry was employed to investigate the plasma dynamics by means of the electron density distribution time development, as well as the disks and foil fragments velocity measurements. Dimensions and shapes of craters were obtained by crater replica technology and microscopy measurement. Experimental results were complemented by analytical theory and computer simulations to help their interpretation. This way the values of laser energy absorption coefficient, ablation loading efficiency and efficiency of energy transfer, as well as 2-D shock wave generation at the laser-driven macroparticle impact, were obtained from measured craters parameters for both wavelengths of laser radiation. Computer simulations allowed us to obtain an energy absorption balance of incident laser energy for both wavelengths employed.

6

Investigation of plasma ablation and crater formation processes in the Prague Asterix Laser System laser facility

Borodziuk S., Kasperczuk A., Pisarczyk T., Gus'kov S., Ullschmied J., Kralikova B., Rohlena K., Skala J., Kalal M., Pisarczyk P.

Optica Applicata

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2004

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Vol. 34, nr 1

31-42

EN

The present investigation of the processes of ablative plasma generation and formation of craters was carried out at the Prague Asterix Laser System (PALS) iodine laser facility. Experiments were performed with broad range of laser beam intensities (1013-1016 W/cm2), focal spot radii (35–600 mm), and two laser wavelengths (l1 = 1.315 mm and l3 = 0.438 mm). The laser beam was focused on the surface of the massive solid aluminum targets. The main goal of our study was to estimate conversion efficiency of the laser beam energy into the energy of shock waves for different mechanisms of laser beam–target interaction. The expansion of plasma generated as a result of the interaction process was observed by means of the 3-frame interferometry. Dimensions and shapes of the craters were determined using optical microscopy and wax-replica technique.

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Application of the 3-frame interferometry and the crater replica method for investigation of laser accelerated macroparticles interacting with massive targets in the Prague Asterix Laser System (PALS) experiment

Borodziuk S., Kasperczuk A., Pisarczyk T., Demchenko N.N., Gus’kov S., Rozanov V. B., Kalal M., Limpouch J., Ullschmied J., Rohlena K., Skala J., Kondrashov V. N., Pisarczyk P.

Optica Applicata

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2004

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Vol. 34, nr 3

385-403

EN

In the present paper results from our experiments with macroparticles, accelerated at first to high speeds by the PALS iodine laser and subsequently hitting massive targets and creating craters, are presented. The main aim of these investigations concerned the influence of wavelength on the efficiency of macroparticles acceleration and creation of craters. To this end, two different harmonics of the PALS laser beam (l1 = 1.315 mm and l3 = 0.438 mm) and several types of targets (simple massive planar Al targets as well as much more elaborated double targets consisting of 6 mm thick Al foils or disks placed in front of the massive target at the distance of either 200 mm or 500 mm) were used. All these targets were irradiated by the iodine laser beam with its parameters very much the same for both harmonics: the energy of 130 J, the focal spot diameter of 250 mm, and the pulse duration of 400 ps. Velocities of accelerated extracted foil fragments or disks as well as electron density distributions of plasma streams were determined by means of the 3-frame interferometry. Shapes and volumes of craters were obtained employing the crater acetate cellulose replica technology and microscopy measurements. The data from these experiments provided valuable information concerning the ablative plasma generation and crater creation processes.

8

Experimental and theoretical investigations of crater formation in an aluminium target in a PALS experiment

Borodziuk S., Doskach I., Gus'kov S., Jungwirth K., Kálal M., Kasperczuk A., Kralikova B., Krousky E., Limpouch J., Masek K., Pfeifer M., Pisarczyk P., Pisarczyk T., Rohlena K., Rozanov V., Skala J., Ullschmied J.

Nukleonika

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2004

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Vol. 49, nr 1

7-14

EN

Experimental and theoretical results of investigations of the iodine laser - Al solid target interactions on the PALS (Prague Asterix Laser System) facility are presented. The experimental investigations of laser interaction with massive Al targets devoted to shock wave propagation in solids and crater formation physics are presented. Experiments were performed with the use of high intensity laser pulses (1013 15 W/cm2) for two laser wavelengths (0.438 mi m and 1.315 mi m) and four laser beam radii (from 35 mi m up to 600 ěm). The crater dimensions were measured using optical microscopy and a wax-replica technique. Plasma expansion out of the target was measured via three-frame interferometry. Theoretical model of the postpulse crater formation by the shock wave propagating and decaying in solids after the end of the laser pulse is presented and applied for the explanation of the results obtained in experiments.

9

A method for the determination of spatial electron density distribution in great Plasma-Focus devices

Kasperczuk A., Paduch M., Pisarczyk T., Tomaszewski K.

Nukleonika

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2002

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Vol. 47, nr 1

23-26

EN

Determination of the electron density of plasma generated in a great plasma-focus device by means of interferometry is very difficult or sometimes impossible. In order to determine spatial electron density distributions of plasma in a PF-1000 device, a special method was prepared, with the use of plasma images obtained by means of both an optical frame camera and shadowgraphy. Analysis of plasma radiation in the very narrow Äë = 60 Ĺ optical range allowed us to determine the relation between intensity of the plasma radiation and the electron density. It was also shown that the influence of electron temperature on plasma radiation is not large. The presented method allowed us to obtain spatial electron density distributions of plasma (in relative units) in the PF-1000 device. By means of this method a number of important information about the plasma-focus phenomenon was obtained.

10

Application of automated interferometric system for investigation of the behaviour of a laser-produced plasma in strong external magnetic fields.

Kasperczuk A., Pisarczyk T.

Optica Applicata

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2001

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Vol. 31, nr 3

571-597

EN

Achievements of the authors in the field of technical and numerical problems of multi-frame interferometry are presented. A three-channel interferometric system with an automatic image processing for laser-produced plasma is described. The measurements of electron density distributions in a plasma generated by a laser and confined by a strong magnetic field (up to 15 T) are the main part of this work. Numerical analysis of interferograms of the plasma and numerical methods of the reconstruction of electron density spatial profiles, both in an axially symmetrical plasma and in a plasma stream of disturbed axial symmetry are presented in more detail.

11

Investigation of dynamic and stability of laser-produced plasma in strong external magnetic field.

Pisarczyk T., Kasperczuk A., Miklaszewski R., Zakharov Y.P.

Optica Applicata

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2000

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Vol. 30, nr 1

41-59

EN

The paper presents results of studies of the behaviour of a laser-produced plasma in strong external axial and transverse magnetic field of 5-20 T in induction generated from a flat teflon target at the laser power densities of about 10/sup 14/ Wcm/sup -2/. The investigations were carried on by means of three-frame interferometry and a non-contact magnetic probe, the so-called remote magnetic probe (RMP). The dynamics of the process of creation of the diamagnetic cavity, its shape and dimensions have been determined. Also computer simulation of plasma expansion by a 2D MHD code was made.

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Badanie dynamiki i stabilności plazmy laserowej w polu magnetycznym o różnej geometrii

Pisarczyk T.

Prace Instytutu Podstawowych Problemów Techniki PAN

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1998

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nr 6

1-139

PL

W pracy przedstawiono wyniki badań eksperymentalnych i numerycznego modelowania plazmy wytwarzanej z tarczy ciała stałego. Do diagnosyki plazmy laserowej wytwarzanej przy podłużnej geometrii pola magnetycznego stosowano trójkadrowy układ interferometryczny z blokiem elektronicznego zapisu i analizy interferogramów, umożliwiającym uzyskanie przestrenno-czasowych rozkładów koncentracji elektronowej. W przypadku poprzecznej geometrii pola magnetycznego, ze wzglęgu na silne zaburzenie osiowej symetrii plazmy przez pole magnetyczne, do określenia przestrzennych rozkładów koncentracji elektronowej opracowano i zastosowano dwuekspozycyjną interferometrię tomograficzną. W badaniach tych, jako diagnostykę uzupełniającą, stosowano pomiary zmian pola megnetycznego za pomocą oddalonej sondy magnetycznej. Podstawą przedstawionych w pracy analiz były szczegółowe wyniki badań dotyczące określenia wpływu zewnętrznego pola magnetycznego (dla dwóch różnych jego geometrii) na przestrzenne rozkłady koncentracji elektronowej plazmy laserowej. Szczegółowa analiza tych rozkładów w połączeniu z dwuwymiarowym modelowaniem pokazała, że ekspansja plazmy w podłużnym polu magnetycznym prowadzi do powstania dwóch zasadniczo odmiennych konfiguracji plazmowych w zależności od sposobu oświetlenia tarczy promieniowaniem laserowym.