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 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 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 The PHEBUS experimental facility operating at 250 ps and 0·53 μm

1988 ◽  
Vol 6 (1) ◽  
pp. 93-103 ◽  
Author(s):  
G. Thiell ◽  
A. Adolf ◽  
M. Andre ◽  
N. Fleurot ◽  
D. Friart ◽  
...  
Keyword(s):  
Large Scale ◽  
Focal Spot ◽  
Laser Light ◽  
Laser System ◽  
Plasma Expansion ◽  
One Dimensional ◽  
Spatial Intensity Distribution ◽  
Flux Limiter ◽  
Laser Facility ◽  
Inverse Bremsstrahlung Absorption

The experiments reported in this paper demonstrate that the PHEBUS laser facility is now currently being operated with high performances (4 TW with 250 ps pulses at 0·527 μm wavelength).The output energy of the 2-beam PHEBUS laser system can be focused either in a small focal spot (80% of the incident energy is in a 220 μm diameter focal spot) for high intensity experiments (≥5 × 1015 W cm−2) or in very large spots (a few mm in diameter) at moderate intensities (1013 − 2·5 × 1014 W cm−2), for large scale experiments. It is shown that the spatial intensity distribution in the target plane is primarily due to intensity independent aberrations and to diffraction. Laser light absorption in plane aluminum and gold targets are interpreted in terms of inverse bremsstrahlung absorption that may account for 70 to 90% of absorbed energy. Finally, the plasma expansion is shown to be very planar and comparison with one-dimensional Lagrangian simulations gives flux limiter values of 0·03 and 0·02 respectively for Al and Au targets.

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

2011 ◽  
Vol 30 (1) ◽  
pp. 1-7 ◽  
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.

scholarly journals Laser-produced plasma expansion in a uniform magnetic field

1992 ◽  
Vol 10 (4) ◽  
pp. 723-735 ◽  
Author(s):  
U. S. Begimkulov ◽  
B. A. Bryunetkin ◽  
V. M. Dyakin ◽  
G. A. Koldashov ◽  
S. N. Priyatkin ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Experimental Data ◽  
Numerical Analysis ◽  
Uniform Magnetic Field ◽  
Plasma Jet ◽  
Plasma Cloud ◽  
Plasma Expansion ◽  
Laser Produced Plasma ◽  
Cloud Evolution ◽  
The Magnetic Field

Laser-produced plasma cloud evolution in a magnetic field is investigated up to 3 kg using photographs and spectroheliograms. Generation of a plasma jet, oriented across the magnetic field, was detected, whose emission increases with the field strength and is more distinct for multicharged ions. The effects of the field on the interaction of closely located laser-produced plasma clouds were studied as well. The results of numerical analysis comply with experimental data on plasma behavior in the magnetic field.

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.

Wavefront correction for near diffraction-limited focal spot on a 6×100 J/1-ns laser facility

2003 ◽  
Author(s):  
Julien Fuchs ◽  
Benoit F. Wattellier ◽  
Ji P. Zou ◽  
Jean-Christophe Chanteloup ◽  
H. Bandulet ◽  
...  
Keyword(s):  
Focal Spot ◽  
Wavefront Correction ◽  
Laser Facility

scholarly journals Dependence of laser accelerated protons on laser energy following the interaction of defocused, intense laser pulses with ultra-thin targets

2011 ◽  
Vol 29 (3) ◽  
pp. 345-351 ◽  
Author(s):  
C.M. Brenner ◽  
J.S. Green ◽  
A.P.L. Robinson ◽  
D.C. Carroll ◽  
B. Dromey ◽  
...  
Keyword(s):  
Laser Pulse ◽  
Focal Spot ◽  
Laser Pulse Energy ◽  
Laser Energy ◽  
Spot Size ◽  
Proton Flux ◽  
Focal Spot Size ◽  
Order Of Magnitude ◽  
Laser Focal Spot ◽  
Accelerated Protons

AbstractThe scaling of the flux and maximum energy of laser-driven sheath-accelerated protons has been investigated as a function of laser pulse energy in the range of 15–380 mJ at intensities of 1016–1018 W/cm2. The pulse duration and target thickness were fixed at 40 fs and 25 nm, respectively, while the laser focal spot size and drive energy were varied. Our results indicate that while the maximum proton energy is dependent on the laser energy and laser spot diameter, the proton flux is primarily related to the laser pulse energy under the conditions studied here. Our measurements show that increasing the laser energy by an order of magnitude results in a more than 500-fold increase in the observed proton flux. Whereas, an order of magnitude increase in the laser intensity generated by decreasing the laser focal spot size, at constant laser energy, gives rise to less than a tenfold increase in observed proton flux.

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