scholarly journals Studies of plasma interactions with tungsten targets in PF-1000U facility

Nukleonika ◽  
2016 ◽  
Vol 61 (2) ◽  
pp. 149-153
Author(s):  
Maryna S. Ladygina ◽  
Elzbieta Skladnik-Sadowska ◽  
Dobromil R. Zaloga ◽  
Marek J. Sadowski ◽  
Monika Kubkowska ◽  
...  
Keyword(s):  
Experimental Studies ◽  
Optical Emission ◽  
Target Surface ◽  
Sample Surface ◽  
Optical Microscope ◽  
High Plasma ◽  
Spectral Lines ◽  
Optical Measurements ◽  
Plasma Stream ◽  
Plasma Parameters

Abstract This paper presents results of experimental studies of tungsten samples of 99.95% purity, which were irradiated by intense plasma-ion streams. The behaviour of tungsten, and particularly its structural change induced by high plasma loads, is of great importance for fusion technology. The reported measurements were performed within a modified PF-1000U plasma-focus facility operated at the IFPiLM in Warsaw, Poland. The working gas was pure deuterium. In order to determine the main plasma parameters and to study the behaviour of impurities at different instants of the plasma discharge, the optical emission spectroscopy was used. The dependence of plasma parameters on the initial charging voltage (16, 19 and 21 kV) was studied. Detailed optical measurements were performed during interactions of a plasma stream with the tungsten samples placed at the z-axis of the facility, at a distance of 6 cm from the electrode outlets. The recorded spectra showed distinct WI and WII spectral lines. Investigation of a target surface morphology, after its irradiation by intense plasma streams, was performed by means of an optical microscope. The observations revealed that some amounts of the electrodes material (mainly copper) were deposited upon the irradiated sample surface. In all the cases, melted zones were observed upon the irradiated target surface, and in experiments performed at the highest charging voltage there were formed some cracks.

scholarly journals Research on interactions of plasma streams with CFC targets in the Rod Plasma Injector facility

Nukleonika ◽  
2016 ◽  
Vol 61 (2) ◽  
pp. 179-183
Author(s):  
Dobromil R. Zaloga ◽  
Roch Kwiatkowski ◽  
Elżbieta Skladnik-Sadowska ◽  
Marek J. Sadowski ◽  
Katarzyna Nowakowska-Langier
Keyword(s):  
Fibre Composite ◽  
Emission Spectra ◽  
Optical Emission ◽  
Target Surface ◽  
Spectral Lines ◽  
Optical Measurements ◽  
Plasma Stream ◽  
Operational Parameters ◽  
Carbon Fibre Composite ◽  
Sem Images

AbstractThis paper present results of optical spectroscopy studies of interactions of intense plasma streams with a solid target made of carbon fibre composite (CFC). The experiments were carried out within the Rod Plasma Injector (RPI) IBIS facility. The optical measurements were performed first for a freely propagating plasma stream in order to determine the optimal operational parameters of this facility. Optical emission spectra (OES) were recorded for different operational modes of the RPI IBIS device, and spectral lines were identified originating from the working gas (deuterium) as well as some lines from the electrode material (molybdenum). Subsequently, optical measurements of plasma interacting with the CFC target were performed. In the optical spectra recorded with the irradiated CFC samples, in addition to deuterium and molybdenum lines, many carbon lines, which enabled to estimate erosion of the investigated targets, were recorded. In order to study changes in the irradiated CFC samples, their surfaces were analysed (before and after several plasma discharges) by means of scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS) techniques. The analysis of the obtained SEM images showed that the plasma irradiation induces noticeable changes in the surface morphology, for example vaporisation of some carbon fibres and formation of microcracks. The obtained EDS images showed that upon the irradiated target surface, some impurity ions are also deposited, particularly molybdenum ions from the applied electrodes.

scholarly journals Study of tungsten surface interaction with plasma streams at DPF-1000U

Nukleonika ◽  
2015 ◽  
Vol 60 (2) ◽  
pp. 293-296 ◽  
Author(s):  
Marina S. Ladygina ◽  
Elzbieta Skladnik-Sadowska ◽  
Dobromil R. Zaloga ◽  
Karol Malinowski ◽  
Marek J. Sadowski ◽  
...  
Keyword(s):  
Electron Density ◽  
Stark Effect ◽  
Initial Conditions ◽  
Experimental Studies ◽  
Flow Characteristics ◽  
Optical Microscope ◽  
Spectral Lines ◽  
Surface Erosion ◽  
Maximum Plasma ◽  
Plasma Stream

Abstract In this note experimental studies of tungsten (W) samples irradiated by intense plasma-ion streams are reported. Measurements were performed using the modified plasma focus device DPF-1000U equipped with an axial gas-puffing system. The main diagnostic tool was a Mechelle®900 optical spectrometer. The electron density of a freely propagating plasma stream (i.e., the plasma stream observed without any target inside the vacuum chamber) was estimated on the basis of the half-width of the Dβ spectral line, taking into account the linear Stark effect. For a freely propagating plasma stream the maximum electron density amounted to about 1.3 × 1017 cm−3 and was reached during the maximum plasma compression. The plasma electron density depends on the initial conditions of the experiments. It was thus important to determine first the plasma flow characteristics before attempting any target irradiation. These data were needed for comparison with plasma characteristics after an irradiation of the investigated target. In fact, spectroscopic measurements performed during interactions of plasma streams with the investigated W samples showed many WI and WII spectral lines. The surface erosion was determined from mass losses of the irradiated samples. Changes on the surfaces of the irradiated samples were also investigated with an optical microscope and some sputtering and melting zones were observed.

scholarly journals PARAMETERS OF HYDROGEN PLASMA STREAMS IN QSPA-M AND THEIR DEPENDENCE ON EXTERNAL MAGNETIC FIELD

2021 ◽  
pp. 61-64
Author(s):  
M.S. Ladygina ◽  
Yu.V. Petrov ◽  
D.V. Yeliseev ◽  
V.A. Makhlai ◽  
N.V. Kulik ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Electron Density ◽  
Hydrogen Plasma ◽  
Experimental Studies ◽  
Optical Emission ◽  
Plasma Electron ◽  
Plasma Stream ◽  
Visible Radiation ◽  
Order Of Magnitude ◽  
Plasma Electron Density

Present experimental studies are aimed at analysis of hydrogen plasma stream parameters in various working regimes of QSPA-M operation. Temporal distributions of plasma electron density are reconstructed with optical emission spectroscopy. The magnetic field influence on plasma streams parameters is analyzed. It is shown that in regimes with additional magnetic field the plasma electron density increases by an order of magnitude in comparison with a density value without magnetic field. The plasma velocity and energy density parameters as well as their temporal behaviors were estimatedin different operating regimes of QSPA-M facility. Features of plasma visible radiation were analyzed. This information is important for QSPA-M applications in experiments on interaction of powerful plasma streams with material surfaces.

scholarly journals Optical Emission Spectroscopic Analysis of Plasma Plume during Pulsed Laser Deposition of PZT

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
S. Sasanka Kumar ◽  
R. Reshmi ◽  
N. V. Joshy ◽  
A. C. Saritha ◽  
M. K. Jayaraj
Keyword(s):  
Electron Temperature ◽  
Early Stage ◽  
Time Of Flight ◽  
Optical Emission ◽  
Target Surface ◽  
Number Density ◽  
Plasma Parameters ◽  
Partial Pressures ◽  
Emission Spectroscopic Analysis ◽  
Almost All

Spatial variation in intensity of spectral emission, electron temperature, number density, and the time of flight (TOF) of ions and neutrals at various oxygen ambiances has been investigated on ferroelectric lead zirconium titanate (PZT) plasma using optical emission spectroscopy. Plasma produced by ablating PZT ceramic target using Nd-YAG laser operating at the third harmonics (λ=355 nm, τ=10 ns, repetition frequency 10 Hz) was investigated at various oxygen partial pressures and at various distances from the target surface. Here energy density for laser fluence was fixed as 3.13 Jcm−2 and distance from the target and ambient gas pressure were varied. The electron number density Ne and electron temperature of the PZT plasma at the early stage of plume expansion were measured as 1.7×1017 Jcm−2 and 13200 K, respectively, and thus verified the existence of local thermodynamic equilibrium (LTE). Time of flight spectra (TOF) of neutral and singly ionized species in plasma were recorded. The result shows that plasma parameters and velocity of species are of same order for various oxygen partial pressures but have a decreasing tendency with distance. The energy of almost all species in the plume become more or less same at 0.1 mbar. These conditions favour the growth of perovskite PZT thin films.

Laser Ablation of Ti-Al Alloy in Vacuum and Air Environments

2012 ◽  
Vol 217-219 ◽  
pp. 2257-2264 ◽  
Author(s):  
Yue Hua Liu ◽  
Xiang Dong Liu ◽  
Ming Chen ◽  
Ming Wen Zhao
Keyword(s):  
High Power ◽  
Laser Energy ◽  
Optical Emission ◽  
Target Surface ◽  
Al Alloy ◽  
Laser Irradiance ◽  
Air Plasma ◽  
High Power Laser ◽  
Power Laser ◽  
Plasma Parameters

The time-resolved optical emission spectroscopy of Ti-Al alloy plasma produced by the Nd:YAG high-power laser pulses with wavelength of 1064nm was investigated both in air and vacuum conditions. The comparative studies gave detailed insights that the plasmas produced in air were much hotter and denser. The quantitative descriptions indeed suggested that a cascade avalanche process would be happen followed by air plasma firstly, before the laser impacting the target surface. On the other hand, the laser energy may be considerably attenuated via hotter and denser plasma, the amount of laser energy on the target surface remarkably decreased in air condition. In addition, at high-power laser irradiance levels, there was an auto regulatory area near the target surface and the plasma parameters tend to be saturated

Spectroscopic study and numerical simulation of low-pressure radio-frequency capacitive discharge with argon downstream

2017 ◽  
Vol 95 (2) ◽  
pp. 190-200 ◽  
Author(s):  
Murat Tanişli ◽  
İsmail Rafatov ◽  
Neslihan Şahin ◽  
Sercan Mertadam ◽  
Süleyman Demir
Keyword(s):  
Radio Frequency ◽  
Power Flow ◽  
Optical Emission Spectroscopy ◽  
Fluid Model ◽  
Optical Emission ◽  
Low Pressure ◽  
Spectral Lines ◽  
Rf Power ◽  
Plasma Parameters ◽  
Discharge Parameters

In this study, the characteristic properties and plasma parameters of capacitive radio frequency (RF) argon (Ar) discharge and supplementary discharge at low pressure are investigated with optical emission spectroscopy (OES). The wavelengths of spectral lines from OES are obtained between 650–900 nm. Using OES lines and related experimental data, the electron temperatures for different RF power, flow, and measurement periods are determined. Eventually, the properties of plasma including the electron temperature are identified. In addition, the numerical modelling of the discharge parameters is carried out by using the “extended” fluid model for plasma, and consistency between numerical and experimental results is discussed.

Characterization of high microwave power atmospheric pressure plasma torch

2018 ◽  
Vol 96 (7) ◽  
pp. 851-854
Author(s):  
B. Turkyilmaz ◽  
D. Mansuroglu ◽  
I.U. Uzun-Kaymak
Keyword(s):  
Microwave Power ◽  
Atmospheric Pressure ◽  
Plasma Torch ◽  
Microwave Plasma ◽  
Atmospheric Pressure Plasma ◽  
Optical Emission ◽  
Spectral Lines ◽  
Plasma Parameters ◽  
Boltzmann Plot ◽  
Plasma Torches

An atmospheric pressure microwave plasma torch operating at 2.45 GHz frequency using a surfaguide waveguide fed by argon gas at a constant rate is characterized at various microwave power settings. Coarse optical emission spectroscopy technique is used to diagnose the plasma parameters. The Boltzmann plot method is implemented to measure the electron temperature. Using the Doppler shift of the strong argon atomic spectral lines, the plasma velocity is determined. These results are in good agreement with earlier studies conducted on similar microwave plasma torches at a lower power setting. In this study, we exceed the previous power limitations observed in earlier studies and scan the microwave power in increments up to 2 kW.

scholarly journals Enhancement of Laser-induced Breakdown Spectroscopy (LIBS) Signal Subject to the Magnetic Confinement and Dual Pulses-=SUP=-*-=/SUP=-

2021 ◽  
Vol 129 (4) ◽  
pp. 538
Author(s):  
Atif Hussain ◽  
Gao Xun ◽  
Haroon Asghar ◽  
Muhammad Azam ◽  
Qura-tul-Ain -=SUP=-1-=/SUP=- ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Optical Emission ◽  
Magnetic Confinement ◽  
Signal Enhancement ◽  
Spectral Lines ◽  
Laser Induced Breakdown Spectroscopy ◽  
Plasma Parameters ◽  
Maximum Enhancement ◽  
Breakdown Spectroscopy ◽  
Laser Induced Breakdown

In this work, a comparative study for the laser-induced breakdown spectroscopy (LIBS) of aluminium (Al) target has been performed by using the two kinds of enhancement techniques namely, magnetic confinement and double pulse-LIBS (DP-LIBS). Firstly, the signal enhancement of Al plasma by combining the LIBS with an external magnetic field was exposed. Secondly, the signal enhancement by configuring the dual-pulses action in LIBS was performed. We found that the optical emission lines and plasma parameters (electron temperature and density) showed significant enhancement in the presence of magnetic field and DP-LIBS. During the magnetic confinement, the maximum enhancement factors of about 6 and 8 were achieved for the spectral line Mg (II) 279.5 nm and Al (II) 280.1 nm, respectively. An enhancement factor was reached up to 12-folds for the various spectral lines in DP-LIBS. Our results have significance in improving the LIBS sensitivity. Keywords: LIBS, spectral lines, magnetic confinement, Boltzmann, dual pulses

scholarly journals Dry Etching Performance and Gas-Phase Parameters of C6F12O + Ar Plasma in Comparison with CF4 + Ar

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1595
Author(s):  
Nomin Lim ◽  
Yeon Sik Choi ◽  
Alexander Efremov ◽  
Kwang-Ho Kwon
Keyword(s):  
Gas Phase ◽  
Photoelectron Spectroscopy ◽  
Reactive Ion Etching ◽  
Research Work ◽  
Optical Emission ◽  
Plasma Parameters ◽  
Ion Etching ◽  
Ar Plasma ◽  
Ar Gas ◽  
Etching Selectivity

This research work deals with the comparative study of C6F12O + Ar and CF4 + Ar gas chemistries in respect to Si and SiO2 reactive-ion etching processes in a low power regime. Despite uncertain applicability of C6F12O as the fluorine-containing etchant gas, it is interesting because of the liquid (at room temperature) nature and weaker environmental impact (lower global warming potential). The combination of several experimental techniques (double Langmuir probe, optical emission spectroscopy, X-ray photoelectron spectroscopy) allowed one (a) to compare performances of given gas systems in respect to the reactive-ion etching of Si and SiO2; and (b) to associate the features of corresponding etching kinetics with those for gas-phase plasma parameters. It was found that both gas systems exhibit (a) similar changes in ion energy flux and F atom flux with variations on input RF power and gas pressure; (b) quite close polymerization abilities; and (c) identical behaviors of Si and SiO2 etching rates, as determined by the neutral-flux-limited regime of ion-assisted chemical reaction. Principal features of C6F12O + Ar plasma are only lower absolute etching rates (mainly due to the lower density and flux of F atoms) as well as some limitations in SiO2/Si etching selectivity.

Long-pulse plasma source for SMOLA helical mirror

2021 ◽  
Vol 87 (2) ◽  
Author(s):  
Ivan A. Ivanov ◽  
V. O. Ustyuzhanin ◽  
A. V. Sudnikov ◽  
A. Inzhevatkina
Keyword(s):  
Magnetic Field ◽  
Gas Flow ◽  
Supply Voltage ◽  
Hydrogen Plasma ◽  
Plasma Source ◽  
Lanthanum Hexaboride ◽  
Plasma Stream ◽  
Plasma Parameters ◽  
Plasma Properties ◽  
Plasma Gun

A plasma gun for forming a plasma stream in the open magnetic mirror trap with additional helicoidal field SMOLA is described. The plasma gun is an axisymmetric system with a planar circular hot cathode based on lanthanum hexaboride and a hollow copper anode. The two planar coils are located around the plasma source and create a magnetic field of up to 200 mT. The magnetic field forms the magnetron configuration of the discharge and provides a radial electric insulation. The source typically operates with a discharge current of up to 350 A in hydrogen. Plasma parameters in the SMOLA device are Ti ~ 5 eV, Te ~ 5–40 eV and ni ~ (0.1–1)  × 1019 m−3. Helium plasma can also be created. The plasma properties depend on the whole group of initial technical parameters: the cathode temperature, the feeding gas flow, the anode-cathode supply voltage and the magnitude of the cathode magnetic insulation.

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