scholarly journals Interaction of two plasma jets produced successively from Cu target

2010 ◽  
Vol 28 (3) ◽  
pp. 497-504 ◽  
Author(s):  
A. Kasperczuk ◽  
T. Pisarczyk ◽  
J. Badziak ◽  
S. Borodziuk ◽  
T. Chodukowski ◽  
...  
Keyword(s):  
Laser Beam ◽  
Target Surface ◽  
Plasma Jet ◽  
Plasma Jets ◽  
Diagnostic Tools ◽  
Jet Formation ◽  
Simple Method ◽  
Third Harmonic ◽  
Laser Facility ◽  
Focal Spot Diameter

AbstractOur earlier papers demonstrate a very simple method of plasma jet formation, consisting in irradiating a massive planar target of a relatively high atomic number by a partly defocused laser beam. Our present interest is concentrated on interaction of the plasma jet with other media. This paper is aimed at investigations of interaction of two jets launched successively on Cu target. Our attention was paid to the role of radiative cooling in the plasma jet formation. The experiment was carried out at the PALS iodine laser facility. The laser provided a 250-ps (full width at half maximum) pulse with energy of 130 J at the third harmonic frequency (λ3 = 0.438 µm). Two successive jets were produced on a massive flat Cu target provided with a cylindrical channel 5 mm long and 400 µm in diameter. Since the focal spot diameter of the laser beam on the target surface was larger than that of the channel (800 µm), the annular irradiation of the target face resulted in creation of the first plasma jet, whereas the second jet was produced by action of the central part of laser beam on the channel wall. Three-frame interferometric system, X-ray streak camera, and a set of ion collectors were used as diagnostic tools.

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

2009 ◽  
Vol 27 (3) ◽  
pp. 415-427 ◽  
Author(s):  
A. Kasperczuk ◽  
T. Pisarczyk ◽  
N.N. Demchenko ◽  
S.Yu. Gus'kov ◽  
M. Kalal ◽  
...  
Keyword(s):  
Target Material ◽  
Plasma Jet ◽  
Plasma Jets ◽  
Diagnostic Tools ◽  
Jet Formation ◽  
Third Harmonic ◽  
Spot Radius ◽  
Theoretical Investigations ◽  
Irradiation Geometry ◽  
Hydrodynamic Code

AbstractRecent 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. This paper is aimed at explanation of this difference by considering mechanisms responsible for plasma jet formation, i.e., the radiative cooling of ablative plasma and the influence of target irradiation annular profile speculated hitherto, newly complemented by different expansion regimes of the Cu and plastic plasmas (provided by numerical simulations). The experiment was carried out with the PALS iodine laser. Two different planar massive targets, plastic and Cu, as well as the plastic target covered by thin Cu layers of various thicknesses were irradiated by the third harmonic laser beam of energy of 30 J, pulse duration of 250 ps (full width at half maximum), and the focal spot radius of 400 µm. To find the most suitable range of these layers (from 28 to 190 nm) a simple analytical model of laser-driven evaporation was developed. Three-frame laser interferometer and an X-ray streak camera were used as two main diagnostic tools. Numerical modeling was performed with the use of two-dimensional hydrodynamic code ATLANT-HE. Results provided from experiments and theoretical analyses have proved that the process of plasma jet formation is rather complex. Relative importance of the three mechanisms mentioned above depends on the target irradiation geometry as well as the target material used.

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

2007 ◽  
Vol 25 (3) ◽  
pp. 425-433 ◽  
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.

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

2008 ◽  
Vol 26 (2) ◽  
pp. 189-196 ◽  
Author(s):  
A. Kasperczuk ◽  
T. Pisarczyk ◽  
M. Kalal ◽  
M. Martinkova ◽  
J. Ullschmied ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Laser Energy ◽  
Focal Point ◽  
Target Surface ◽  
Plasma Jets ◽  
Point Position ◽  
Laser Plasma Interactions ◽  
Opposite Case ◽  
Laser Facility ◽  
Focusing Lens

AbstractThis paper 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). It was demonstrated that these two opposite focal point positions give rise to significantly different laser-plasma interactions: with either depression or maximum of the laser intensity distribution in the center of the beam, respectively. It was also verified that the focal point position inside of the target is favorable for plasma jets creation, whereas the opposite case is more effective for acceleration of flyers.

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

2009 ◽  
Vol 27 (1) ◽  
pp. 115-122 ◽  
Author(s):  
A. Kasperczuk ◽  
T. Pisarczyk ◽  
Ph. Nicolai ◽  
Ch. Stenz ◽  
V. Tikhonchuk ◽  
...  
Keyword(s):  
Laser Beam ◽  
High Speed ◽  
Laser System ◽  
Target Surface ◽  
Pinhole Camera ◽  
Plasma Jets ◽  
Incidence Geometry ◽  
X Ray ◽  
Ambient Gases ◽  
Ar Gas

AbstractInteractions 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 PALS third harmonic (0.438 µm), with pulse duration of 250 ps (full width at half maximum), and energy of 100 J was employed in two irradiation geometries: with an incidence normal to the target surface and with an oblique one (30° with respect to the target normal), in order to minimize the heating of the ambient gas by the laser beam. The results of these interaction experiments, in particular, those obtained in case of the oblique incidence geometry, are presented and discussed. They show the effect of the double shock formation in ambient gases: starting by the ablative plasma action, followed by that of the jet.

scholarly journals Modeling of annular-laser-beam-driven plasma jets from massive planar targets

2012 ◽  
Vol 30 (3) ◽  
pp. 445-457 ◽  
Author(s):  
V. Kmetík ◽  
J. Limpouch ◽  
R. Liska ◽  
P. Váchal
Keyword(s):  
Laser Beam ◽  
Laser Intensity ◽  
Laser System ◽  
Beam Profile ◽  
Plasma Jets ◽  
Laboratory Astrophysics ◽  
Jet Formation ◽  
Dynamic Simulations ◽  
Plasma Dynamic ◽  
Annular Laser

AbstractProduction of sharply collimated high velocity outflows – plasma jets from massive planar targets by a single laser beam at PALS facility is clarified via numerical simulations. Since only a few experimental data on the intensity distribution in the interaction beam near the focus are available for the PALS facility, the laser beam profile was calculated by a numerical model of the laser system and the interaction optics. The obtained intensity profiles are used as the input for plasma dynamic simulations by our cylindrical two-dimensional fluid code PALE. Jet formation due to laser intensity profile with a minimum on the axis is demonstrated. The outflow collimation improves significantly for heavier elements, even when radiative cooling is omitted. Using an optimized interaction beam profile, a homogeneous jet with a length exceeding its diameter by several times may be reliably generated for applications in laboratory astrophysics and impact ignition studies.

scholarly journals Ion acceleration and plasma jets driven by a high intensity laser beam normally incident on thin foils

2013 ◽  
Vol 31 (4) ◽  
pp. 613-625 ◽  
Author(s):  
Magdi Shoucri ◽  
Jean-Pierre Matte ◽  
François Vidal
Keyword(s):  
Laser Beam ◽  
Radiation Pressure ◽  
High Intensity ◽  
Critical Density ◽  
Plasma Jet ◽  
Target Thickness ◽  
Skin Depth ◽  
Plasma Jets ◽  
Distribution Functions ◽  
Neutral Plasma

AbstractWe study the problem of the radiation pressure acceleration of ions and the formation of plasma jets, driven by a high-intensity circularly polarized laser beam normally incident on thin plasma targets. We use an Eulerian Vlasov code to solve the one-dimensional relativistic Vlasov-Maxwell equations for both electrons and ions. We consider the case of a high density plasma with n/ncr = 100, where ncr is the critical density. Three cases are studied with different target thicknesses, to investigate the physical processes involved when decreasing the target thickness from several electron skin depths down to the order of one skin depth. The results show a more important acceleration of the ions when the thickness is decreased. Although we observe in all cases a neutral plasma jet ejected from the back of the target, the evolution of the system which leads to the formation of this neutral plasma jet is different in the three cases considered. In each case, this evolution will be studied in details. Also, a leak or ejection of electrons from the back of the target is observed in the thinnest case treated (thickness of the order of the skin depth), before the formation of the neutral plasma jet, a regime called leaky light sail radiation pressure acceleration. The absence of noise in the Eulerian Vlasov code allows an accurate representation of the phase-space structures of the distribution functions.

scholarly journals High-Speed Video Analysis of the Process Stability in Plasma Spraying

2021 ◽  
Author(s):  
K. Bobzin ◽  
M. Öte ◽  
M. A. Knoch ◽  
I. Alkhasli ◽  
H. Heinemann
Keyword(s):  
Plasma Spraying ◽  
High Speed ◽  
Plasma Jet ◽  
Plasma Jets ◽  
Time Dependent ◽  
Acquisition Time ◽  
Fast Fourier Transformation ◽  
Frequency Spectra ◽  
Dependent Signal ◽  
The Stability

AbstractIn plasma spraying, instabilities and fluctuations of the plasma jet have a significant influence on the particle in-flight temperatures and velocities, thus affecting the coating properties. This work introduces a new method to analyze the stability of plasma jets using high-speed videography. An approach is presented, which digitally examines the images to determine the size of the plasma jet core. By correlating this jet size with the acquisition time, a time-dependent signal of the plasma jet size is generated. In order to evaluate the stability of the plasma jet, this signal is analyzed by calculating its coefficient of variation cv. The method is validated by measuring the known difference in stability between a single-cathode and a cascaded multi-cathode plasma generator. For this purpose, a design of experiment, covering a variety of parameters, is conducted. To identify the cause of the plasma jet fluctuations, the frequency spectra are obtained and subsequently interpreted by means of the fast Fourier transformation. To quantify the significance of the fluctuations on the particle in-flight properties, a new single numerical parameter is introduced. This parameter is based on the fraction of the time-dependent signal of the plasma jet in the relevant frequency range.

scholarly journals Tiny Cold Atmospheric Plasma Jet for Biomedical Applications

Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 249
Author(s):  
Zhitong Chen ◽  
Richard Obenchain ◽  
Richard E. Wirz
Keyword(s):  
Biomedical Applications ◽  
Plasma Jet ◽  
Discharge Voltage ◽  
Plasma Jets ◽  
Atmospheric Plasma ◽  
Physical Parameters ◽  
Cold Atmospheric Plasma ◽  
Water Metal ◽  
Plasma Probe ◽  
Jet Nozzle

Conventional plasma jets for biomedical applications tend to have several drawbacks, such as high voltages, high gas delivery, large plasma probe volume, and the formation of discharge within the organ. Therefore, it is challenging to employ these jets inside a living organism’s body. Thus, we developed a single-electrode tiny plasma jet and evaluated its use for clinical biomedical applications. We investigated the effect of voltage input and flow rate on the jet length and studied the physical parameters of the plasma jet, including discharge voltage, average gas and subject temperature, and optical emissions via spectroscopy (OES). The interactions between the tiny plasma jet and five subjects (de-ionized (DI) water, metal, cardboard, pork belly, and pork muscle) were studied at distances of 10 mm and 15 mm from the jet nozzle. The results showed that the tiny plasma jet caused no damage or burning of tissues, and the ROS/RNS (reactive oxygen/nitrogen species) intensity increased when the distance was lowered from 15 mm to 10 mm. These initial observations establish the tiny plasma jet device as a potentially useful tool in clinical biomedical applications.

Wiggler smoothing of laser beam intensity at ICF target surface

1995 ◽  
Author(s):  
I. P. Bashkatov ◽  
A. Y. Goltsov ◽  
A. N. Kolomiyskii ◽  
N. G. Kovalskii ◽  
V. V. Kryzhko ◽  
...  
Keyword(s):  
Laser Beam ◽  
Target Surface ◽  
Beam Intensity ◽  
Laser Beam Intensity ◽  
Icf Target
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