Negative atomic hydrogen ion (H$^{-}$) densities were measured in a pulsed low-pressure E-mode inductively-coupled radio-frequency (rf) driven plasma in hydrogen by means of laser photodetachment and a Langmuir probe. This investigation focuses on the influence of different metallic surface materials on the volume production of H$^{-}$ ions. The H$^{-}$ density was measured above a thin disc of either tungsten, stainless steel, copper, aluminium, or molybdenum placed onto the lower grounded electrode of the plasma device as a function of gas pressure and applied rf power. For copper, aluminium, and molybdenum the H$^{-}$ density was found to be quite insensitive to pressure and rf power, with values ranging between 3.6x10$^{14}$ to 5.8x10$^{14}$ m$^{-3}$. For stainless steel and tungsten, the H$^{-}$ dependency was found to be complex, apart from the case of a similar linear increase from 2.9x10$^{14}$ to 1.1x10$^{15}$ m$^{-3}$ with rf power at a pressure of 25 Pa. Two-photon absorption laser induced fluorescence was used to measure the atomic hydrogen densities and phase resolved optical emission spectroscopy was used to investigate whether the plasma dynamics were surface dependent. An explanation for the observed differences between the two sets of investigated materials is given in terms of surface reaction mechanisms for the creation of vibrationally excited hydrogen molecules.
Positive and negative ions forming so-called pair plasma differing in sign of their charge and asymmetric in mass and temperature support a new electrostatic mode. Bernstein mode for a pair ions and pair ions with contribution of electrons in pair plasma both cases are investigated. By solving the linearized Vlasov equation along Maxwell equations, a generalized expression for the Bernstein waves is derived by employing the Maxwell distribution function. In paper we discuss the different types of ions Bernstein waves and comparison of the symmetry and asymmetry on these ions Bernstein waves. W…
Materials containing hydrogen and high-Z ion species are used in a variety of high energy density physics (HED) applications, and it becomes increasingly important to investigate transport properties of these substances as they become fully-ionized multispecies plasmas. In particular, of significant practical interest, is the analysis of the plasma viscosity as it can determine stability and turbulence properties of the HED system. It has been pointed out by D. Ryutov [Phys. Plasmas 3, 4336 (1996)] that the presence of a substantial amount of hydrogen in a multispecies plasma can significantly…
Theoretical framework for power dissipation in low temperature plasmas in corona equilibrium is developed. The framework is based on fundamental conservation laws and reaction cross sections and is only weakly sensitive to plasma parameters, e.g. electron temperature and density. The theory is applied to low temperature atomic and molecular hydrogen laboratory plasmas for which the plasma heating power dissipation to photon emission, ionization and chemical potential is calculated. The calculated photon emission is compared to recent experimental results.
A comprehensive parametric study of plasma-grain interaction for non-Maxwellian streaming ions in steady-state employing particle-in-cell simulations is delineated. Instead of considering the inter-grain interaction potential to be the linear sum of isolated grain potentials, we incorporate the numerical advancement developed fully for grain shielding by including nonlinear contributions from the plasma and shadowing effect. The forces acting on grains versus inter-grain distance, streaming velocity of the ions, and impact of trapped ions density (number) are characterized for non- Maxwellian …
The multi-species plasma of natural or laboratory origin is often considered to host nonlinear ion-acoustic waves. We present calculations of ion fluxes induced by nonlinear ion-acoustic waves in a plasma consisting of multiple ion populations, electrons, and dust. The following plasma models are considered: an electron-ion plasma with cold ions, a bi-ion plasma with two types of warm positively charged ions, and a dusty bi-ion plasma. It is found that in the electron-ion plasma, the wave-induced ion flux is directed oppositely to the phase speed of the nonlinear ion-acoustic wave. In the bi-i…
The dispersion equation, describing the instability development of vortex turbulence excitation in cylindrical plasma in crossed radial electric and axial magnetic fields with taking into account the longitudinal inhomogeneity and finite time of leaving of plasma electrons and ions from the system, has been derived. It is shown that the finite length of system time and finite time of system leaving of plasma electrons and ions leads to the appearance of the instability threshold and to decrease of growth rate of its development.
Unmagnetized collisionless plasma system consisting of positive- and negative ions, and electrons are considered to study the head-on collision of ion-acoustic shock waves (IASWs) and its effects on the formation of shock (monotonic and oscillatory) waves and phase shift. The soliton solution is derived from the two-sided Korteweg-de Vries Burger (KdVB) equations. The KdVB equations are obtained using extend Poincare-Lighthill-Kuo (ePLK) method. It is assumed that the negative ions are immobile and the electrons follow the Boltzmann energy distribution in the plasma. The effects of plasma para…
We propose a model of ion-electron plasma (or nucleus-electron plasma) that accounts for the electronic structure around nuclei (i.e. ion structure) as well as for ion-ion correlations. The model equations are obtained through the minimization of an approximate free-energy functional, and it is shown that the model fulfills the virial theorem. The main hypotheses of this model are 1) nuclei are treated as classical indistinguishable particles 2) electronic density is seen as a superposition of a uniform background and spherically-symmetric distributions around each nucleus (system of ions in a…
The energy deposition and the atomic processes, such as the electron-capture, ionization, excitation and radiative-decays for slow heavy ions in plasma remains an unsolved fundamental problem. Here we investigate, both experimentally and theoretically, the stopping of 100 keV=u helium ions in a well-defined hydrogen plasma. Our precise measurements show a much higher energy loss than the predictions of the semi-classical approaches with the commonly used effective charge. By solving the Time Dependent Rate Equation (TDRE) with all the main projectile states and for all relevant atomic processe…
In the present paper we introduce a full and closed system of atomic kinetic equations on fractions of atomic energy levels taking into account the effect of the plasma ions electric microfield mixing dynamics. The system of equations that we present is deduced from a full quantum multi-atomic states density matrix master equation. The analytical derivation of this atomic kinetic system of equations is based on the introduction of a new hierarchy chain of equations involving a new set of statistical atomic variables. The final system of atomic kinetic equations is obtained by introducing relat…
Novel methods for diagnostics of molecular hydrogen plasma processes, such as ionization, production of high vibrational levels, dissociation of molecules via excitation to singlet and triplet states and production of metastable states, are presented for molecular hydrogen plasmas in corona equilibrium. The methods are based on comparison of rate coefficients of plasma processes and optical emission spectroscopy of lowest singlet and triplet transitions, i.e. Lyman-band ($B^1Σ^+_u \rightarrow X^1Σ^+_g$) and molecular continuum ($a^3Σ^+_g \rightarrow b^3Σ^+_u$), of the hydrogen molecule in VUV …
The energy distributions of Ta ions produced in a nanosecond laser-heated plasma at 4$\times$10$^{15}$ W/cm$^{2}$ are experimentally and theoretically investigated. They are measured far from the target with an electrostatic spectrometer and charge collectors. Shadowgraphy and interferometry are used to characterize the plasma dynamics in the first nanoseconds of the plasma expansion for electron densities ranging from 10$^{18}$ to 10$^{20}$ cm$^{-3}$. The experimental data clearly show two components in the energy distributions which depend on the ion charge states. These components are discu…
In a recent paper (Phys. Plasmas 25, 061203, 2018), the authors have presented the analysis of the electric ion drift velocity experienced by heavy ions created in a plasma submitted to a low magnetic field. Unfortunately, they have used the classical ExB drift formula that is valid only in slab geometry. The authors have not taken into account that the cylindrical geometry induces a slow electric drift of the ions around the axis of the column. Moreover, the low magnetization of the ions induces a Larmor radius that is larger than the diameter of the plasma column. The movement of the ions im…
Self-trapping and acceleration of ions in laser-driven relativistically transparent plasma are investigated with the help of particle-in-cell simulations. A theoretical model based on ion wave breaking is established in describing ion evolution and ion trapping. The threshold for ion trapping is identified. Near the threshold ion trapping is self-regulating and stops when the number of trapped ions is large enough. The model is applied to ion trapping in three-dimensional geometry. Longitudinal distributions of ions and the electric field near the wave breaking point are derived analytically i…
An unprecedented increase of kinetic energy of laser accelerated heavy ions is demonstrated. Ultra thin gold foils have been irradiated by an ultra short laser pulse at an intensity of $6\times 10^{19}$ W/cm$^{2}$. Highly charged gold ions with kinetic energies up to $> 200$ MeV and a bandwidth limited energy distribution have been reached by using $1.3$ Joule laser energy on target. $1$D and $2$D Particle in Cell simulations show how a spatial dependence on the ions ionization leads to an enhancement of the accelerating electrical field. Our theoretical model considers a varying charge densit…
The linear electron acoustic waves propagating in plasmas with two kappa-distributed electrons and stationary ions are investigated. The temperatures of the two electrons are assumed to be the same, but the kappa indices are not. It shows that if one kappa index is small enough and the other one is large enough, a weak damping regime of the electron acoustic waves exists. The dispersions and damping rates are numerically studied. The parameter spaces for the weakly damped electron acoustic waves are analyzed. Moreover, the electron acoustic waves in the present model are compared with those in…
Hydrogen is largely produced via natural gas reforming or electrochemical water-splitting, leaving organic solid feedstocks under-utilized. Plasma technology powered by renewable electricity can lead to the sustainable upcycling of plastic waste and production of green hydrogen. In this work, low-temperature atmospheric pressure plasma reactors based on transferred arc (transarc) and gliding arc (glidarc) discharges are designed, built, and characterized to produce hydrogen from low-density polyethylene (LDPE) as a model plastic waste. Experimental results show that hydrogen production rate an…
Megaelectron volt (MeV) alpha particles will be the main source of plasma heating in magnetic confinement fusion reactors. Yet, instead of heating fuel ions, most of the energy of alpha particles is transferred to electrons. Furthermore, alpha particles can also excite Alfvenic instabilities, previously considered as detrimental. Contrary to expectations, we demonstrate efficient ion heating in the presence of MeV ions and strong fast-ion driven Alfvenic instabilities in recent experiments on the Joint European Torus (JET). Detailed transport analysis of these experiments with state-of-the-art…
Extreme ultraviolet (EUV) induced pulsed plasma is unique due to its transient characteristics: the plasma switches between non-thermal state (when EUV power is ON at the beginning of the pulse) and thermal state (end of the pulse at ~ 20 us). It is shown that although electron drag force acting on nm size particles in hydrogen plasma is negligible compared to the ion drag force at the beginning of the pulse, however it can be dominant at the end of the pulse and can play important role in particle transport leading to defectivity issues for semiconductor chip production technologies.
A model of the fluid nonlinear frequency shift of ion acoustic waves (IAWs) in multi-ion species plasmas is presented, which considers the effect of ion temperature. Because the thermal ion exists in plasmas in inertial confinement fusion (ICF) and also solar wind, which should be considered in nonlinear frequency shift of IAWs. However, the existing models [Berger et al., Physics of Plasmas 20, 032107 (2013); Q. S. Feng et al., Phys. Rev. E 94, 023205 (2016)] just consider the cold ion fluid models. This complete theory considering multi-ion species and thermal ions will calculate the frequen…
We consider diffusion caused by a combined influence of the Hall effect and electric currents, and argue that such diffusion forms chemical inhomogeneities in plasma. The considered mechanism can be responsible for the formation of element spots in laboratory and astrophysical plasmas. Such current-driven diffusion can be accompanied by the propagation of a particular type of waves which have not been considered earlier. In these waves, the impurity number density oscillare alone and their frequency is determined by the electric currents and sort of impurity ions. These compositional waves exi…
Head-on collisions of ion-acoustic solitary waves in a collisionless plasma consisting of cold ions and Boltzmann electrons are studied using the particle-in-cell simulation. It is shown that the collision of solitary waves can occur under different scenarios. Solitary waves preserve or do not preserve their amplitudes and shapes after a collision, depending on their initial amplitudes. The range of initial amplitudes, at which a solitary wave preserves its identity after collisions, is established. The use of a diagram of initial amplitudes of colliding solitary waves to consider possible col…
Thermal equilibrium rate can play an important role in the energy deposition of beam to the fuel in fast ignition due to high temperature difference between projectile ions and background plasma ions. In this study the temperature equilibration rate of a quasi-monoenergetic deuteron beam with an equimolar Deuterium-Tritium fusion plasma with a Maxwellian energy distribution is calculated by kinetic theory equations. In this theory, binary collisions is described by the Boltzman equation and collective effects is described by the Lenard-Balescu equation. The obtained results show that at higher…
The role of liquid ions in the dusty plasma produced by laser ablation in a liquid environment is still unclear. For that purpose, we utilized the self-similar approach to investigate the effect of liquid ions on plasma expansion front. The fluid equations have been used for dust particles and ion species in addition to superthermal electron distribution. We treat the expansion process in the absence and existence of liquid ions. The impact of the dust-to-ion initial number density ratio, superthermality factor kappa, dust-to-electrons initial temperature ratio, and dust-ions atomic number on …
In this work, dynamics of multi-charged ions emitted from an aluminum plasma produced by Q switched Nd: Yag laser is studied using time of flight (TOF) measurements from Langmuir Probe (LP) and spectroscopy (STOF) under Ar ambient of 0.02 mbar. The temporal evolution of multi-charged ions, background neutrals and ions is systematically studied for varying laser intensities. The temporal evolution shows all the species have double peak structure for all the laser intensities considered in the study. The fast peak is sharp whereas the slow peak is broad similar to that observed in previous studi…
HELicon Experiment for Negative ion source (HELEN-I) with single driver is developed with a focus on the production of negative hydrogen ions. In the Helicon wave heated plasmas, very high plasma densities ($\sim10^{19} m^{-3}$) can be attained with electron temperatures as low as $\sim$1 eV in the downstream region. These conditions favor the production of negative hydrogen ions. In HELEN-I device at IPR, helicon plasma is produced using Hydrogen gas in a diverging magnetic field, created by a permanent ring magnet. RF Power ($P_{RF}$) of 800-1000W at 13.56 MHz frequency is applied to a Nagoy…
The dispersion relation of kinetic Alfvén wave in inertial regime is studied in a three component non-degenerate streaming plasma. A lin- ear dispersion relation using fluid- Vlasov equation for quantum plasma is also derived. The quantum correction CQ raised due to the insertion of Bohm potential in Vlasov model causes the suppression in the Alfven wave frequency and the growth rates of instability. A number of analytical expressions are derived for various modes of propagation. It is also found that many system parameters, i.e, streaming velocity, dust charge, num- ber density and quantum co…
We study the dust surface potential for the complex dusty plasma with negative ions and with a three-parameter non-Maxwell velocity distribution. The plasma contains electrons, positive ions, negative ions, and negatively charged dust particles. By using the current equilibrium condition, we derive the relationship between the normalized dust surface potential and the dusty plasma parameters such as the normalized dust number density, the temperature ratio of negative ions to electrons, the density ratio of negative ions to positive ions, and the charge number of negative ions. The numerical a…
An investigation of dust-acoustic solitary waves in unmagnetized dusty plasma whose constituents are inertial charged dust grains, Boltzmannian electrons and nonthermal ions has been conducted. The pseudo potential as well as the reductive perturbation methods have been used in high and small amplitude limits. The existence of solitary waves of a positive as well as a negative potential is reported.
Using the asymptotic iteration method (AIM) we investigate the variation in the 1s energy levels of hydrogen and helium-like static ions in fully degenerate electron gas. The semiclassical Thomas-Fermi (TF), Shukla-Eliasson (SE) and corrected Shukla-Eliasson (cSE) models are compared. It is remarked that these models merge into the vacuum level for hydrogen and helium-like ions in the dilute classical electron gas regime. While in the TF model hydrogen ground state level lifts monotonically towards the continuum limit with increase in the electron concentration, in the SE and cSE models univer…
We analyze atomic structures of plasma embedded aluminum (Al) atom and its ions in the weakly and strongly coupling regimes. The plasma screening effects in these atomic systems are accounted for using the Debye and ion sphere (IS) potentials for the weakly coupling and strongly coupling plasmas, respectively. Within the Debye model, special attention is given to investigate the spherical and non-spherical plasma-screening effects considering in the electron-electron interaction potential. The relativistic coupled-cluster (RCC) method has been employed to describe the relativistic and electron…
We have numerically studied the evolution of the heavy ions that expand in a cold background plasma at a large scale. Two typical collective behaviors of the heavy ions are identified with the conditions where only the traversing heavy ion's initial total mass is different. Our work has demonstrated that a difference in the initial total mass of the moving heavy ions is able to induce completely different collective behaviors of the plasma. The simulation is performed via the hybrid model, in which the ions and electrons are treated as classical particles and mass-less fluid, respectively. Due…
We construct the model of a quantum spherically symmetric plasma structure based on radial oscillations of ions. We suppose that ions are involved in ion-acoustic plasma oscillations. We find the exact solution of the Schrödinger equation for an ion moving in the self-consistent oscillatory potential of an ion-acoustic wave. The system of ions is secondly quantized and its ground state is constructed. Then we consider the interaction between ions by the exchange of an acoustic wave. It is shown that this interaction can be attractive. We describe the formation of pairs of ions inside a plasma …
The energy distribution functions of ions in the cathodic arc plasma using composite AlCr cathodes were measured as a function of the background gas pressure in the range 0.5 to 3.5 Pa for different cathode compositions and gas atmospheres. The most abundant aluminium ions were Al$^{+}$ regardless of the background gas species, whereas Cr$^{2+}$ ions were dominating in Ar and N$_2$ and Cr$^{+}$ in O$_2$ atmospheres. The energy distributions of the aluminium and chromium ions typically consisted of a high-energy fraction due to acceleration in the expanding plasma plume from the cathode spot an…
