Effect Of Plasma Environment Research Articles

Gravitational lensing around a dual-charged stringy black hole in plasma background

One of the strongest tools to verify the predictions of general relativity (GR) has been the gravitational lensing around various compact objects. Using a dual charged stringy black hole produced from dilaton-Maxwell gravity, we investigate the impact of the plasma parameter on gravitational lensing and black hole shadow in this study. Detailed investigations are performed to mark the impact of the homogeneous and non-homogeneous plasma environment on the electric and magnetic charge parameters of stringy black hole. In order to compare the results, we have also considered the vacuum scenario of the dual charged stringy black hole. Our results show that the effect of homogeneous plasma environment is much stronger in comparison to vacuum for the case of electrically charged stringy black hole. However, in the case of magnetically charged stringy black hole, the deflection angle gets decreased in presence of the homogeneous plasma medium. It has been observed that the radius of the shadow increases in a non-homogeneous plasma environment for electrically charged stringy black hole, whereas it decreases for magnetically charged stringy black hole in presence of the same plasma environment. This study aims to investigate how different plasma environments influence these fascinating astrophysical phenomena.

Effect of dense plasma environment and external magnetic field on atomic structure and radiative properties of Ar XVII

Atomic structures and radiative properties of He like Ar XVII in the presence of dense plasma environments and external magnetic field have been presented within the framework of the relativistic theory. For this purpose, the relativistic configuration interaction method by incorporating the generalized b-potential and external magnetic field has been implemented. Plasma screening effect on 1s2 1S0 → 1s2p 3P1 transitions of Ar XVII ion in the presence of an external magnetic field has been investigated. We also studied the Zeeman splitted energies and predicted the excitation energies of Ar XVII ion for the magnetic sublevels 1s2p 3P0 (MJ = 0), 3P1 (MJ = 0, ±1), 3P2 (MJ = 0, ±1, ±2), 1P1 (MJ =0, ±1). Our calculated results are in excellent agreement with National Institute of Science and Technology (NIST) database and other theoretical available data.

Study of characteristics elementary atomic processes in the neon-like multicharged ions plasma within an energy approach

We present the theoretical foundations of an advanced relativistic approach to computing the main energy, spectral characteristics of radiative-collisional processes in the plasma (in particular, the Debye plasma) of atomic as the example, neon-like) ions with simultaneous, quantitatively consistent consideration of the complex relativistic, interelectron exchange-correlation and plasma environment effects. The approach is based on the combination of a relativistic energy approach (S-matrix Gell-Mann and Low formalism), the relativistic gauge-invariant many-body perturbation theory with optimized Dirac-Fock-Sturm and Debye-Hückel approximations with accounting for the plasma environment effects with possible generalization on the presence of an additional external electromagnetic field. The fundamental point of our approach is the selection of the optimized Dirac-Fock-Sturm zeroth approximation and application of the consistent procedure for constructing a one-quasiparticle representation (basis’s of relativistic wave functions) in compliance with the principle of gauge invariance, in particular, by minimizing a gauge-noninvariant contributions to the radiative widths of the atomic (ionic) levels due to the complex exchange-correlation effects. The electron-ion collision strength and the dioelect5ron capture rate etc are determined within the presented theory.

Plasma Analyzer for the Chinese FY-3E Satellite: In-Orbit Performance and Ground Calibration

The plasma analyzer (PMA) on the Fengyun-3E (FY-3E) meteorological satellite series is a critical sensor of the space environment monitoring package that is capable of the comprehensive in situ detection of the thermal plasma environment and surface discharge effects. In this paper, we conducted a thorough evaluation of the PMA’s performance and reliability through a combination of ground-based laboratory calibration and in-orbit testing. During the ground-based calibration, the PMA underwent assessments for the energy range, field of view (FOV), and measurement accuracy, and obtained the detection accuracy and the geometric factors. During the in-orbit testing, the PMA successfully obtained the typical distribution characteristics of low-energy ions and electrons in orbital space regions, as well as the precipitating particles in the middle and high latitudes of both hemispheres. Notably, the PMA observed an expansion of the particle distribution in the high-latitude regions during a moderate geomagnetic storm. The results from both the ground-based calibration and in-orbit testing demonstrated that the PMA met the requirements for thermal plasma detection, with reliable and scientifically valid in-orbit detection data. These results provide a crucial foundation for studying spatial weather variations, improving the accuracy of space environment forecasts and enhancing disaster detection and monitoring capabilities.

Compressed lithium atom under Debye screening

AbstractIn the present paper, we introduced two approximation methods to investigate the spherically compressed lithium atom under the influence of Debye plasma. Specifically, the diffusion and the variational Monte Carlo methods are used for the first time to study this case. We incorporated an exponential screening into the nuclear Coulomb potential to account for the plasma influence. We focused our investigation on analyzing the combined effect of compression and plasma environment on the behavior of the lithium atom in its ground state. The resulting outcomes exhibited consistent pattern across various confinement radii and Debye plasma lengths . Many of the results are novel contributions, as they have yet to be explored. Moreover, the findings from this study demonstrated reasonable agreement with the limited existing theoretical results.

Physiochemical etching characteristics and surface analysis of Y2O3-MgO nanocomposite under different CF4/Ar/O2 plasma atmospheres

During plasma etching in the semiconductor manufacturing process, not only the wafers but also the ceramic components that make up the interior of the chamber are influenced by the highly reactive plasma. Because chemical and physical etching work concurrently, and selective etching is possible by controlling the plasma gas composition, it is essential to develop novel ceramics with outstanding resistance to various plasma environments that do not produce contamination particles; this will allow us to elevate production yield of chips and overall equipment effectiveness (OEE). Herein, we report the plasma etching behavior of 50:50 vol% Y2O3-MgO nanocomposite ceramics under different CF4/Ar gas ratios conditions. It was found that the erosion depths and surface roughness changes of this material were much lower than those values of reference materials under both chemical and physical etching. Effects of plasma environment on the penetration depth of fluorine on the nanocomposite surface and of physical sputtering attack were also investigated. The results indicate that a nanocomposite with fine grains and high density can decrease particle generation and improve its life cycle under strong bias voltage and various plasma gas conditions, thereby showing itself a promising material for next-generation ceramic components in the semiconductor manufacturing process.

Plasma environment effects on K lines of astrophysical interest

Aims. We calculate the plasma environment effects on the ionization potentials (IPs) and K-thresholds used in the modeling of K lines for all the ions belonging to the isonuclear sequences of abundant elements apart from oxygen and iron, namely: carbon, silicon, calcium, chromium, and nickel. These calculations are used to extend the data points for the fits of the universal formulae, first proposed in our fourth paper of this series, to predict the IP and K-threshold lowerings in any elemental ion. Methods. We used the fully relativistic multi-configuration Dirac–Fock method and approximated the plasma electron-nucleus and electron-electron screenings with a time-averaged Debye–Hückel potential. Results. We report the modified ionization potentials and K-threshold energies for plasmas characterized by electron temperatures and densities in the ranges of 105−107 K and 1018−1022 cm−3. In addition, the improved universal fitting formulae are obtained. Conclusions. We conclude that since explicit calculations of the atomic structures for each ion of each element under different plasma conditions is impractical, the use of these universal formulae for predicting the IP and K-threshold lowerings in plasma modeling codes is still recommended. However, their comparatively moderate to low accuracies may affect the predicted opacities with regard to certain cases under extreme plasma conditions that are characterized by a plasma screening parameter of μ > 0.2 a.u., especially for the K-thresholds.

Effect of plasma environment on spectral and structural properties of H-like C, N and O ions

The novel studies of the dense plasma on transition properties and level structures for H-like Carbon, Nitrogen and Oxygen ions are presented. Plasma effect is included through the confined ion sphere plasma model. We have also included relativistic effects through mass-correction, Darwin and spin-orbit terms during the calculation. The energy level shift, oscillator strengths, transition rates, plasma shifts and probability densities are calculated by using Ritz’s variation method for different ion sphere plasma concentrations. The variation parameters are calculated by minimizing the expectation value of the energy. Eigenstate, probability and average position are calculated with plasma concentration for the internal structure of the system. We have compared our calculated data with experimental National Institute of Science and Technology (NIST) database and other theoretical results in the literature and it is showing a good quantitative agreement. The study may be very useful in astrophysical and fusion plasma.

Elastic scattering of electron in neutral plasma: Interaction model and plasma environment effects

Elastic scattering of electrons in a plasma is studied for its pivotal role in relating transport properties to plasma composition. A unified effective potential model is developed to describe the interactions between electrons and atoms/ions in plasma. It not only contains the static Coulomb, polarization, and exchange interaction but also considers plasma environment effects with a Muffin-tin model based on the Roothaan–Hartree–Fock atomic wave functions. For electron–electron and electron–ion interactions, the dynamical screening effect is also considered by a velocity-dependent screening length. The validity of the potential model is demonstrated in the specific case of argon plasma. The calculated differential, total, and momentum transfer cross sections, as well as the electrical conductivities at varying plasma densities and temperatures, are compared to available experimental data and other calculations. These comparisons indicate that the proposed potential has correct low density limit behavior and works well for plasma in a wide range of densities and temperatures, including warm dense matter.

Plasma environment effects on K lines of astrophysical interest

Aims.Within the framework of compact-object accretion disks, we calculate plasma environment effects on the atomic structure and decay parameters used in the modeling of K lines in lowly charged iron ions, namely Fe II–Fe VIII.Methods.For this study, we used the fully relativistic multiconfiguration Dirac–Fock method approximating the plasma electron–nucleus and electron-electron screenings with a time-averaged Debye-Hückel potential.Results.We report modified ionization potentials, K-threshold energies, wavelengths, radiative emission rates, and Auger widths for plasmas characterized by electron temperatures and densities in the ranges 105 − 107K and 1018 − 1022cm−3. In addition, we propose two universal fitting formulae to predict the IP and K-threshold lowerings in any elemental ion.Conclusions.We conclude that the high-resolution X-ray spectrometers onboard the future XRISM and ATHENA space missions will be able to detect the lowering of the K edges of these Fe ions due to the extreme plasma conditions occurring in the accretion disks around compact objects.

Effect of Dense Plasma Environment on the Spectroscopic Properties of He-like Ca18+ Ion

Plasma shielding effects on the energy levels and radiative properties of He-like Ca\(^{18+}\) ion under dense plasma conditions have been studied. For this purpose, the multiconfiguration Dirac-Fock method has been implemented by incorporating the ion sphere model potential as a modified interaction potential between the electron and the nucleus. To check the authenticity of our results, independent calculations have been performed using the modified relativistic configuration interaction method. It is observed that the transition energies associated with \(\Delta n = 0\) transitions are blue shifted, whereas red shifted for \(\Delta n \neq 0\) transitions. The variation in transition probabilities and weighted oscillator strengths with plasma densities has also been analyzed. The present results should be beneficial in the plasma modeling and fusion plasma research applications.

Plasma environment effects on K lines of astrophysical interest

Aims. In the context of accretion disks around black holes, we estimate plasma-environment effects on the atomic parameters associated with the decay of K-vacancy states in highly charged iron ions, namely Fe XVII– Fe XXV.Methods. Within the relativistic multiconfiguration Dirac–Fock (MCDF) framework, the electron–nucleus and electron–electron plasma screenings were approximated with a time-averaged Debye–Hückel potential.Results. Modified ionization potentials, K thresholds, wavelengths, radiative emission rates, and Auger widths are reported for astrophysical plasmas characterized by electron temperatures and densities in the ranges 105 − 107K and 1018 − 1022cm−3, respectively.Conclusions. We conclude that the high-resolution microcalorimeters on board future X-ray missions such as XRISM and ATHENA are expected to be sensitive to the lowering of the iron K edge due to the extreme plasma conditions occurring in accretion disks around compact objects.

K‐line X‐ray fluorescence from highly charged iron ions under dense astrophysical plasma conditions

In the present work, we report an investigation of plasma environment effects on the atomic parameters associated with the K‐vacancy states in highly charged iron ions within the astrophysical context of accretion disks around black holes. More particularly, the sensitivity of K‐line X‐ray fluorescence parameters (wavelengths, radiative transition probabilities, and Auger rates) in Fe XVII–Fe XXV ions has been estimated for plasma conditions characterized by an electron temperature ranging from 105 to 107 K and an electron density ranging from 1018 to 1022 cm−3. In order to do this, relativistic multiconfiguration Dirac‐Fock atomic structure calculations have been carried out by considering a time averaged Debye‐Hückel potential for both the electron–nucleus and electron–electron interactions.

Plasma environment effects on K lines of astrophysical interest

Aims. In the context of black-hole accretion disks, the main goal of the present study is to estimate the plasma environment effects on the atomic structure and radiative parameters associated with the K-vacancy states in ions of the oxygen isonuclear sequence. Methods. We used a time-averaged Debye–Hückel potential for both the electron–nucleus and the electron–electron interactions implemented in the fully relativistic multiconfiguration Dirac–Fock (MCDF) method. Results. Modified ionization potentials, K thresholds, Auger widths, and radiative transition wavelengths and rates are reported for O I–O VII in plasma environments with electron temperature and density ranges 105−107 K and 1018−1022 cm−3.

Electron transfer in proton-hydrogen collisions under dense quantum plasma

The effects of dense quantum plasma on 1s → nlm charge transfer, for arbitrary n,l,m, in proton-hydrogen collisions have been studied by employing a distorted wave approximation. The interactions among the charged particles in the plasma have been represented by modified Debye-Huckel potentials. A detailed study has been made to explore the effects of background plasma environment on the differential and total cross sections for electron capture into different angular momentum states for the incident energy in the range 10–1000 keV. For the unscreened case, our results agree well with some of the most accurate results available in the literature.

Atomic structure under external confinement: effect of plasma on the spin orbit splitting, relativistic mass correction and Darwin term for hydrogen-like ions

The effect of Debye and quantum plasma environment on the structural properties such as spin orbit splitting, relativistic mass correction and Darwin term for a few iso-electronic members of hydrogen viz. C5 +, O7 +, Ne9 +, Mg11 +, Si13 +, S15 +, Ar17 +, Ca19 + and Ti21 + has been analysed systematically for the first time for a range of coupling strengths of the plasma. The Debye plasma environment has been treated under a standard screened Coulomb potential (SCP) while the quantum plasma has been treated under an exponential cosine screened Coulomb potential (ECSCP). Estimation of the spin orbit splitting under SCP and ECSCP plasma is restricted to the lowest two dipole allowed states while for the other two properties, the ground state as well as the first two excited states have been chosen. Calculations have been extended to nuclear charges for which appreciable relativistic corrections are noted. In all cases calculations have been extended up to such screening parameters for which the respective excitation energies tend towards their stability limit determined by the ionisation potential at that screening parameter. Interesting behavior of the respective properties with respect to the plasma coupling strength has been noted.

Three-dimensional particle simulation of back-sputtered carbon in electric propulsion test facility

The back-sputtering deposition on thruster surface caused by ion bombardment on chamber wall material affects the performance of thrusters during the ground based electric propulsion endurance tests. In order to decrease the back-sputtering deposition, most of vacuum chambers applied in electric propulsion experiments are equipped with anti-sputtering targets. In this paper, a three-dimensional model of plume experimental system (PES) including double layer anti-sputtering target is established. Simulation cases are made to simulate the plasma environment and sputtering effects when an ion thruster is working. The particle in cell (PIC) method and direct simulation Monte Carlo (DSMC) method is used to calculate the velocity and position of particles. Yamamura's model is used to simulate the sputtering process. The distribution of sputtered anti-sputtering target material is presented. The results show that the double layer anti-sputtering target can significantly reduce the deposition on thruster surface. The back-sputtering deposition rates on thruster exit surface for different cases are compared. The chevrons on the secondary target are rearranged to improve its performance. The position of secondary target has relation with the ion beam divergence angle, and the radius of the vacuum chamber. The back-sputtering deposition rate is lower when the secondary target covers the entire ion beam.

Plasma-screening effects in the astrophysically relevant He-like and Li-like Mg and Fe ions*

The effect of plasma environment on the atomic energy levels of He-like and Li-like Mg and Fe ions have been studied using Debye model. The equation-of-motion coupled-cluster (EOMCC) and Fock-space coupled-cluster (FSCC) formalisms in the relativistic frame work have been adopted to describe the atomic states and the energy levels of the above plasma embedded ions. Salient features of these methods have been described to account the two electron screening effects through the Debye potentials. The two-body screening potential has been derived in the multipole expansion form to evaluate the reduced matrix elements in solving the equation of motion. Using this extended model, we have also predicted that quasi-degeneracy among the energy states having same principal quantum number ($n$) but different angular momentum ($l$) is slacken, whereas fine structure splitting is unaffected with increasing plasma strength. These knowledge are useful in estimatingradiative opacity, photoionization cross sections, line intensities, etc of the aforementioned astrophysical plasmas.

Stark effect modeling in the detailed opacity code SCO-RCG

The broadening of lines by Stark effect is an important tool for inferring electron density and temperature in plasmas. Stark-effect calculations often rely on atomic data (transition rates, energy levels,...) not always exhaustive and/or valid for isolated atoms. We present a recent development in the detailed opacity code SCO-RCG for K-shell spectroscopy (hydrogen- and helium-like ions). This approach is adapted from the work of Gilles and Peyrusse. Neglecting non-diagonal terms in dipolar and collision operators, the line profile is expressed as a sum of Voigt functions associated to the Stark components. The formalism relies on the use of parabolic coordinates within SO(4) symmetry. The relativistic fine-structure of Lyman lines is included by diagonalizing the hamiltonian matrix associated to quantum states having the same principal quantum number n. The resulting code enables one to investigate plasma environment effects, the impact of the microfield distribution, the decoupling between electron and ion temperatures and the role of satellite lines (such as Li-like 1snℓn'ℓ' — 1s2nℓ, Be-like, etc.). Comparisons with simpler and widely-used semi-empirical models are presented.

Influence of the plasma environment on atomic structure using an ion-sphere model

Plasma environment effects on atomic structure are analyzed using various atomic structure codes. To monitor the effect of high free-electron density or low temperatures, Fermi-Dirac and Maxwell-Boltzmann statistics are compared. After a discussion of the implementation of the Fermi-Dirac approach within the ion-sphere model, several applications are considered. In order to check the consistency of the modifications brought here to extant codes, calculations have been performed using the Los Alamos Cowan Atomic Structure (cats) code in its Hartree-Fock or Hartree-Fock-Slater form and the parametric potential Flexible Atomic Code (fac). The ground-state energy shifts due to the plasma effects for the six most ionized aluminum ions have been calculated using the fac and cats codes and fairly agree. For the intercombination resonance line in ${\mathrm{Fe}}^{22+}$, the plasma effect within the uniform electron gas model results in a positive shift that agrees with the multiconfiguration Dirac-Fock value of B. Saha and S. Fritzsche [J. Phys. B 40, 259 (2007)]. Last, the present model is compared to experimental data in titanium measured on the terawatt Astra facility and provides values for electron temperature and density in agreement with the maria code.