Plasma Parameters Research Articles

Helical resonant magnetic perturbation coils for controlling edge localized modes: a robustness study

Abstract Plasma response to helical resonant magnetic perturbation coil current is numerically computed for tokamak plasmas, with optimization results compared with that for conventional window-frame coils. The key aspect of study is the robustness of the proposed new concept against variation of plasma equilibrium parameters including (i) the plasma resistivity, (ii) the toroidal rotation and (iii) the plasma shaping (both elongation and triangularity). Toroidal modeling results yield several important conclusions. First, assuming the same coil current, the optimal helical coils robustly outperform the optimal window-frame coils against variation of the aforementioned plasma equilibrium parameters. Secondly, for a chosen toroidal spectrum, the optimal helical coil geometry including the poloidal location, poloidal coverage and the overall shape, is robust against variation of plasma parameters except the safety factor. Finally, in all cases, optimization based on the plasma response naturally yields a single row of helical coils located near the outboard mid-plane of the torus, ensuring a relatively simple design of the coil geometry.

Construction of Multi-Channel Radio Frequency Plasma Jet System in Atmospheric Pressure and the Diagnosis of Plasma Parameters and I-V Characteristics

In order to produce cold plasma at atmospheric pressure, a multi-channel RF, of (1, 2, 3, and 4 MHz) frequencies, plasma jet system is developed using argon as the working gas. This system consists of two parts, a multi-channel power supply (of a power of 100 W) and a plasma jet. A strong electric field is created that ionizes and excites argon ions. The I-V characteristics of the system and the electron temperature and density for different powers (20, 50, 70, and 80 W), gas flow rates (10, 20, 30, and 40 sccm) (standard centimeter cubic per minute) at different frequencies (1, 2, 3, and 4 MHz) are studied, using the optical emission spectroscopy method. This system can be used in medical applications and material treatment with high efficiency.

Importance of the electron plasma parameter for excitation of chorus and formation of magnetic field irregularity in the region of their excitation

A threshold condition has been established for excitation of VLF electromagnetic radiation with a chorus structure of the dynamic spectrum in the daytime magnetosphere using the BPA (Beam Pulse Amplifier) mechanism for amplifying short noise electromagnetic pulses. The kappa distribution was used as a model function of the electron velocity distribution in the magnetosphere. Calculations performed for this distribution have shown that the threshold for excitation of chorus largely depends on the electron plasma parameter equal to the ratio of gas-kinetic pressure of electrons to magnetic pressure. This pattern is not contradicted by the dependence of the probability of excitation of chorus on the degree of magnetic field irregularity, which we derived from observations made by the Van Allen Probe spacecraft. It is sharp fluctuations in the magnetic field strength near its local minima outside the plasmasphere where the radiation under study can be excited. If there is an irregularity, the probability of detecting chorus is >70 %; and if there is no or very low irregularity, the probability of the absence of any emissions is ~80 %. The results indicate a common reason for the excitation of chorus and the magnetic field irregularity — a small but finite value of the plasma parameter.

Существенность величины плазменного параметра электронов для возбуждения хоров и формирования нерегулярности магнитного поля в области их возбуждения

A threshold condition has been established for excitation of VLF electromagnetic radiation with a chorus structure of the dynamic spectrum in the daytime magnetosphere using the BPA (Beam Pulse Amplifier) mechanism for amplifying short noise electromagnetic pulses. The kappa distribution was used as a model function of the electron velocity distribution in the magnetosphere. Calculations performed for this distribution have shown that the threshold for excitation of chorus largely depends on the electron plasma parameter equal to the ratio of gas-kinetic pressure of electrons to magnetic pressure. This pattern is not contradicted by the dependence of the probability of excitation of chorus on the degree of magnetic field irregularity, which we derived from observations made by the Van Allen Probe spacecraft. It is sharp fluctuations in the magnetic field strength near its local minima outside the plasmasphere where the radiation under study can be excited. If there is an irregularity, the probability of detecting chorus is >70 %; and if there is no or very low irregularity, the probability of the absence of any emissions is ~80 %. The results indicate a common reason for the excitation of chorus and the magnetic field irregularity — a small but finite value of the plasma parameter.

One-Year Impact of Occupational Exposure to Polycyclic Aromatic Hydrocarbons on Sperm Quality.

Polycyclic aromatic hydrocarbons (PAHs) have toxic potential, especially as carcinogens, neurotoxins, and endocrine disruptors. The objective of this study is to know the impact of exposure to PAHs on the reproductive health of male workers who operate in solar thermal plants. Case-control study. A total of 61 men were included: 32 workers exposed to PAH at a solar thermal plant and 29 unexposed people. Seminal quality was studied both at the cellular level (quantity and quality of sperm) and at the biochemical level (magnitudes of oxidative stress in seminal plasma). In exposure to PAHs, a significantly higher seminal leukocyte infiltration was observed, as well as lower activity in seminal plasma of superoxide dismutase (SOD) and a reduced glutathione/oxidised glutathione (GSH/GSSG) ratio. The oxidative stress parameters of seminal plasma did not show a relationship with sperm cellularity, neither in those exposed nor in those not exposed to PAH. One year of exposure to PAH in a solar thermal plant does not have a negative impact on the sperm cellularity of the worker, either quantitatively (sperm count) or qualitatively (motility, vitality, morphology, or cellular DNA fragmentation). However, PAH exposure is associated with lower antioxidant capacity and higher leukocyte infiltration in seminal plasma.

Lactobacilli-Based Pro and Postbiotic Efficacy Are Also Influenced by Other Factors Than Dietary Challenging Conditions.

The present study aimed to confirm the previously reported 'recovery' effect to a challenging diet (CD) of a Lactobacilli-based probiotic (Pro) and its derived postbiotic (Post) in broilers. Identical diet compositions were used, and observations were extended to a second CD diet. A completely randomised block design of 2 × 3 treatment groups with two CDs and three additive conditions (Control, Pro, Post) was used. One additional group received a standard diet (SD). The study involved 1600 one-day-old Ross 308 male broilers. All diets, fed from d1 to 35, were formulated to contain identical nutrients levels, with CDs formulated to be greater than SD in nonstarch polysaccharides using rye and barley (Rye CD) or dry distiller grains with soluble, sunflower and rapeseed meal (DDGS CD). Growth performance parameters, footpad lesions (FPL) score and plasma Ca, P and uric acid concentrations were measured. Compared to SD, birds fed Rye CD and DDGS CD had a higher 1-35 days feed conversion ratio (+3.4 and +4.1%, respectively), due to a higher feed intake for Rye CD (+2.9%) and a lower body weight for DDGS CD (-4.1%). An effect of additive was restricted to Rye CD where Post depressed BW at d28 and d35 (-3.7 and -2.4%, respectively). Compared to Rye CD, DDGS CD lowered plasma Ca/P at d21 (-9.0%) and d35 (-8.1%) and uric acid at d21 (-26%). Pro increased plasma Ca in Rye CD at d21 (+12%) and Post decreased plasma uric acid in DDGS CD at d35 (-25%). All other plasma parameters were not affected. The previously observed recovery effect of a commercial probiotic and postbiotic were not reproducible under highly similar growth conditions, which suggests that both may have specific physiological effects which are only expressed under specific circumstances.

Analysis of discharge parameters of an argon cold atmospheric pressure plasma jet and its impact on surface characteristics of White Grapes

An argon cold atmospheric-pressure plasma (CAP) jet operated using bipolar pulsed power supply has been characterised electro-optically and the discharge parameters are optimized. An analysis has been done on the impact of the argon CAP jet treatment on the surface properties of white grapes for different treatment time period. The developed argon CAP jet is a plasma source based on dielectric barrier discharge (DBD) that has been tuned at various input parameters including applied voltage, frequency, average power consumption, and argon flow rate. Optical Emission Spectroscopy (OES) is used to identify the generated species along with plasma parameters. The collisional–radiative (CR) model is employed to extract the electron density (ne) and electron temperature (Te) from the spectra at the optimised applied voltage of 4 kV, frequency 20 kHz and argon flow rate of 4 slpm. The OES results coupled with the CR model (ne ∼ 1014 cm−3 and Te ∼ 1 eV) and the plasma gas temperature measurement through OH (A-X) transitions (Tg ∼ 310.5 K) show the non-equilibrium nature of the argon CAP jet. A comparative analysis between untreated and treated white grapes reveals that the argon CAP jet treatment influences surface microstructure, increasing hydrophilicity (with a ∼49.3% decrease in water contact angle) along with slight changes in surface temperature (∼5 °C increase), colour (ΔE* < 1.5), and physiochemical properties such as chemical composition (no change) and Total Soluble Solid (TSS) content (∼8.3%). It is inferred that this type of CAP jet treatment of white grapes only affects the physical characteristics of the grape surface and does not alter any chemical compositions.

Pedestal properties of negative triangularity discharges in ASDEX Upgrade

Abstract In this work, we explore the pedestal properties of negative triangularity discharges with upper triangularity of δ u ≈ − 0.35 and with both ion ∇ B drift directions. In all cases, the discharges undergo a transition to H-mode with accompanying edge-localized modes (ELMs) that are not explained by the peeling-ballooning stability analysis alone. A variation in the ion ∇ B drift direction is observed. A lower pressure gradient, shallower radial electric field well and increased temperature fluctuations are measured in the favorable case. In addition, irregular ELMs are present. This difference is more pronounced in electron cyclotron resonance heating (ECRH) plasmas compared to plasmas with combined neutral beam injection and ECRH. A comparative analysis between two discharges, featuring similar plasma parameters but varied shaping, suggests that an interplay between other parameters, such as magnetic shear, the timing of the auxiliary heating and shaping, might play a strong role in low- to high-confinement transitions. While the low shaping discharge maintained L-mode, the high shaping discharge entered H-mode with ELMs, contrary to expectations.

X-ray imaging crystal spectrometer (XICS) diagnostic on the HL-3 tokamak

The construction of an X-ray imaging crystal spectrometer (XICS) diagnostic system on the HL-3 tokamak plays a crucial role in measuring core plasma parameter profiles, including ion temperature, electron temperature, rotational velocity, and impurity radiation profiles. This diagnostic system has been specifically designed to provide detailed and accurate data essential for understanding the behavior and characteristics of tokamak plasma. The resonance spectral line (w line of Ar XVII at 3.9494 Å) and its satellites of helium-like argon ions were chosen on the basis of the HL-3 parameter range. A spherically bent quartz crystal (1012) with a lattice constant of 2d = 4.562 Å, a curvature radius of Rc = 3.0 m, and a size of 10 cm (high) × 5 cm (wide) was mounted on an adjustable displacement platform in the XICS system. The position was adjusted in three dimensions (vertical, inclined, rotation) to effectively record the spectra of the helium-like argon ions. The XICS has a tangential angle of 49° for the toroidal direction in the magnetic axis. This layout accounts for 65.6 % of the toroidal rotation velocity component. The XICS system was set at an 11° poloidal angle in the mid-plane to cover a plasma range of 10 cm above to 50 cm below the mid-plane, which corresponds to the q = 1 surface of the HL-3 plasma (elongation κ > 1.8). This XICS layout produced a spectrum with poloidal and toroidal rotational contributions, requiring decoupling through data processing. In general, because the contribution of the poloidal rotation velocity is much smaller than that of the toroidal rotation velocity, it can be ignored. The XICS system offers a spatial resolution of ∼1.5 cm and a temporal resolution of 5–10 ms on the basis of a high-performance PILATUS3 × 900 K detector. The spectral resolution is λ/Δλ∼4×104, which satisfies the experimental measurement requirements. Preliminary results of ion and electron temperature profiles were obtained for the HL-3 tokamak.

Velocity profile shapes in Alcator C-Mod plasmas

Abstract Toroidal rotation velocity spatial profiles ( r / a &lt; 0.8) have been obtained from C-Mod over a wide range of operational conditions, including H-mode, I-mode, ICRF-heated L-mode and Ohmic L-mode (LOC and SOC), and in plasmas with ITBs, LH wave injection and MCFD. Peaked, flat and hollow rotation profiles have been observed. In H- and I-mode plasmas, generally with co-current peaked profiles, the peaking is correlated with temperature profile peaking, and both increase with toroidal magnetic field (decrease with ρ ∗ ). Any dependence on density peaking is unclear. For Ohmic L-mode discharges, with LOC, the velocity profiles are usually flat and most often directed co-current, while with SOC the profiles are hollow, mostly co-current at the edge and counter-current in the core. Both of these Ohmic rotation states exist with matched density and temperature profiles (and gradients), indicating that neither gradient is relevant during rotation reversals. For plasmas with LH wave injection and discharges with ITBs, the velocity profiles are hollow while the density and temperature profiles exhibit substantial peaking. Broadly speaking for all operational regimes, there is no unifying ordering of the velocity gradient with plasma parameters.

Ultrarelativistic Fe plasma with GJ/cm3 energy density created by femtosecond laser pulses

The generation of a plasma with an ultrahigh energy density of 1.2 GJ/cm3 (which corresponds to about 12 Gbar pressure) is investigated by irradiating thin stainless-steel foils with high-contrast femtosecond laser pulses with relativistic intensities of up to 1022 W/cm2. The plasma parameters are determined by X-ray spectroscopy. The results show that most of the laser energy is absorbed by the plasma at solid density, indicating that no pre-plasma is generated in the current experimental setup.

Extreme ultraviolet emission spectra of a low-pressure microwave neon discharge

In this paper, in order to reveal the discharge mechanism and optimize the extreme ultraviolet (EUV) emission lines in intensity of a low-pressure microwave (MW) neon discharge, the EUV neon spectra is carefully characterized under varied MW powers and neon pressures. The corona balance is verified to be valid for the neon upper levels of the measured EUV lines, and the electron temperature T e is derived by the modified Boltzmann plot method and the line-ratio method. Both results of the methods present a decreasing trend of T e with growing neon pressure, but the values in a range of 1.87-5.77 eV deduced by the former method is in general lower than that calculated by the latter with a range of 2.23–5.58 eV in similar neon pressure range. It is also found that the increase of MW power from 90 to 135 W only leads to a slight increasing of T e . A global model is applied to estimate the electron density n e , which is found to lie in the order of magnitude of 1010 cm−3. The dependence of the plasma parameters on different discharge conditions is analysed in detail, which in turn provide a favourable basis for further optimization of the promising low-pressure MW discharge radiation source.

Tunable topological edge state in plasma photonic crystals

In this study, we found a kind of edge state located at the interface between plasma photonic crystals (PPCs) and traditional photonic crystals, which depends on the property of the photonic band gap rather than the surface defect. Simulation and theoretical analysis show that by adjusting the plasma density, we can change the topological characteristics of the photonic band gap of PPCs. This makes it different from the photonic band gap of traditional PCs, and thus excites or closes the topological edge states. We further discussed the influence of plasma parameters on edge state characteristics, and the results showed that as the plasma density increased, the first photonic band gap (PBG) of the PPCs closed and then reopened, resulting in band inversion and a change in the PBG properties of the PPCs. We can control the generation of edge states through plasma and adjust the frequency and strength of the edge states. After the appearance of edge states, as the plasma density further increases, the first PBG of the PPCs will shift towards high frequencies and deepen. The frequency of edge states will shift towards higher frequencies, and their strength will also increase. We increased the first PBG depth of the PPCs by increasing the number of arrays and found that when the number of the PPCs arrays increased, only the intensity of the edge states would increase while the frequency remained unchanged. Therefore, flexible adjustment of edge state frequency and intensity can be achieved through plasma density and array quantity parameters. Our study demonstrates the properties of topological edge states in plasma photonic crystals, which we believe can provide some guidance for applications based on edge states.

Optical emission spectroscopy as a method for evaluating the change in Si etching structures profile in ICP SF6/C4F8 plasma: Microstructures

In this work, a method for in situ diagnostics of the etching profile of silicon structures (etching window sizes 15–400 μm) using optical emission spectroscopy was proposed. To determine the relationship between the etching profile and plasma parameters, the influence of technological parameters on the etching characteristics (vertical and lateral etching rate, selectivity in relation to photoresist, and sidewall angle) was studied. As a general parameter, which reflects the changes in plasma characteristics depending on the selected technological parameters, the parameter X (C/F ratio in SF6/C4F8 plasma) was introduced. Based on the results obtained, a general pattern between the lateral etching rate, sidewall angle, and optical emission spectra was identified. Thus, ranges of X values, at which the lateral etching rate does not exceed 5 nm/min for 15–30 μm structures and 15 nm/min for 100 μm structures, were estimated: 0.38 ≤ X ≤ 0.77 and 0.28 ≤ X ≤ 0.46, respectively. For 250–400 μm structures, ranges of X values, at which the sidewall angle is acute, straight, and obtuse, were determined: 0.16 ≤ X &amp;lt; 0.29, 0.29 ≤ X ≤ 0.41, 0.41 &amp;lt; X ≤ 0.75, respectively.

Early metabolic and transcriptomic regulation in rainbow trout (Oncorhynchus mykiss) liver by 11-deoxycorticosterone through two corticosteroid receptors pathways

Cortisol hormone is considered the main corticosteroid in fish stress, acting through glucocorticoid (GR) or mineralocorticoid (MR) receptor. The 11-deoxycorticosterone (DOC) corticosteroid is also secreted during stress and could complement the cortisol effects, but this still not fully understood. Hence, we evaluated the early transcriptomic response of rainbow trout (Oncorhynchus mykiss) liver by DOC through GR or MR. Thirty juvenile trout were pretreated with an inhibitor of endogenous cortisol synthesis (metyrapone) by intraperitoneal injection in presence or absence of GR (mifepristone) and MR (eplerenone) pharmacological antagonists for one hour. Then, fish were treated with a physiological DOC dose or vehicle (DMSO-PBS1X as control) for three hours (n = 5 per group). We measured several metabolic parameters in plasma, together with the liver glycogen content. Additionally, we constructed cDNA libraries from liver of each group, sequenced by HiseqX Illumina technology and then analyzed by RNA-seq. Plasma pyruvate and cholesterol levels decreased in DOC-administered fish and only reversed by eplerenone. Meanwhile, DOC increased liver glycogen contents depending on both corticosteroid receptor pathways. RNA-seq analysis revealed differential expressed transcripts induced by DOC through GR (448) and MR (1901). The enriched biological processes to both were mainly related to stress response, protein metabolism, innate immune response and carbohydrates metabolism. Finally, we selected sixteen genes from enriched biological process for qPCR validation, presenting a high Pearson correlation (0.8734 average). These results describe novel physiological effects of DOC related to early metabolic and transcriptomic responses in fish liver and differentially modulated by MR and GR.

Nonlinear dust ion acoustic solitary waves propagation in a magnetized plasma with Tsallis electron distribution

Abstract We have done a theoretical investigation into the propagation of nonlinear dust ion acoustic solitary waves and their soliton properties in a three-component magnetized collisionless plasma consisting of inertial positively charged ions, noninertial electrons following a Tsallis q–distribution, and stationary negatively charged dust grains. We consider a uniform external magnetic field along the z–direction, and the wave propagation occurs obliquely to the magnetic field direction. It is observed that the two types of wave modes namely slow and fast modes, are appears in the linear analysis. By employing the reductive perturbation method, the Korteweg-de Vries (KdV) and modified KdV equations are determined to describe the small amplitude dust ion acoustic soliton. The dependence of several physical plasma parameters including nonextensive q–parameter, magnetic field strength etc. of our plasma on the propagating dust ion acoustic solitary waves potential are numerically examined. This study shows the simultaneous existence of compressive and rarefactive solitons due to the variation of first order nonlinearity coefficient represented by the KdV equation and it is found that there is a critical point for the plasma parameters where the amplitude of the soliton of KdV equation become diverges. The mKdV equation with second order nonlinearity coefficient is derived from there and observed the solitons only with finite amplitude. The present study could be helpful for understanding the nonlinear travelling waves propagating in laboratory and space plasma environments.

Spatial Distribution of the Eddy Diffusion Coefficient in the Plasma Sheet of Earth’s Magnetotail and its Dependence on the Interplanetary Magnetic Field and Geomagnetic Activity based on MMS Satellite Data

The article presents the results of a statistical analysis of the distribution of the eddy diffusion coef-ficient depending on the coordinates in the plasma sheet of Earth’s magnetosphere based on data from the Magnetospheric Multiscale Mission satellite system (MMS) for the period from 2017 to 2022. The localization of satellites inside the plasma sheet was recorded from the concentration and temperature of plasma ions according to the data of the same instruments and the value of plasma parameter β. Significant anisotropy of the eddy diffusion coefficient was revealed. The dependence of the eddy diffusion coefficient on the inter-planetary magnetic field is analyzed, showing that with the southern orientation of the interplanetary magnetic field, the eddy diffusion coefficients are 1.5–2 times greater than with the northern orientation. It is also shown that under disturbed geomagnetic conditions (SML –200 nT), the eddy diffusion coefficients are several times greater than under quiet geomagnetic conditions (SML –50 nT).

Effects of anode evaporation process on the anode sheath characteristics in vacuum arc plasma

Abstract The anode sheath of vacuum arc plasma plays a key role in the generation of anode plasma, but the effects of anode evaporation on the anode sheath remains unclear. In this paper, a theoretical model of a collisional sheath for multi-component plasma coupled with anode evaporation is developed, and the spatial evolution of the anode sheath at different anode surface temperatures is investigated. The results indicate that the distribution of charged particles density and potential in the anode sheath monotonically decreases in the absence or reduction of anode evaporation. When the anode surface temperature exceeds 1900K, a potential hump appears within the sheath. This is due to enhanced anode evaporation increasing the metal vapor density, which intensifies electron impact ionization and charge exchange collisions, resulting in a higher net space charge density. Finally, the effects of various collision reactions and electron temperatures on the potential hump are analyzed. These findings are meaningful for understanding the anode plasma generation mechanism and regulating the anode plasma parameters.&amp;#xD;

Stability optimization of energetic particle driven modes in nuclear fusion devices: the FAR3d gyro-fluid code

The development of reduced models provide efficient methods that can be used to perform short term experimental data analysis or narrow down the parametric range of more sophisticated numerical approaches. Reduced models are derived by simplifying the physics description with the goal of retaining only the essential ingredients required to reproduce the phenomena under study. This is the role of the gyro-fluid code FAR3d, dedicated to analyze the linear and nonlinear stability of Alfvén Eigenmodes (AE), Energetic Particle Modes (EPM) and magnetic-hydrodynamic modes as pressure gradient driven mode (PGDM) and current driven modes (CDM) in nuclear fusion devices. Such analysis is valuable for improving the plasma heating efficiency and confinement; this can enhance the overall device performance. The present review is dedicated to a description of the most important contributions of the FAR3d code in the field of energetic particles (EP) and AE/EPM stability. FAR3d is used to model and characterize the AE/EPM activity measured in fusion devices as LHD, JET, DIII-D, EAST, TJ-II and Heliotron J. In addition, the computational efficiency of FAR3d facilitates performing massive parametric studies leading to the identification of optimization trends with respect to the AE/EPM stability. This can aid in identifying operational regimes where AE/EPM activity is avoided or minimized. This technique is applied to the analysis of optimized configurations with respect to the thermal plasma parameters, magnetic field configuration, external actuators and the effect of multiple EP populations. In addition, the AE/EPM saturation phase is analyzed, taking into account both steady-state phases and bursting activity observed in LHD and DIII-D devices. The nonlinear calculations provide: the induced EP transport, the generation of zonal structures as well as the energy transfer towards the thermal plasma and between different toroidal/helical families. Finally, FAR3d is used to forecast the AE/EPM stability in operational scenarios of future devices as ITER, CFETR, JT60SA and CFQS as well as possible approaches to optimization with respect to variations in the most important plasma parameters.

Three-dimensional transient modeling and simulation of high-current multi-component vacuum arc under transverse magnetic field

This paper established a three-dimensional transient MHD model of a high-current multi-component vacuum arc under a transverse magnetic field (TMF) to simulate the dynamic characteristics of plasma parameters in the uniform motion mode of a contracted arc under lower TMF. The model considered the ionization–recombination process among the multi-components and used the P1 model to calculate the thermal radiation losses. The simulation results show that the ion number density of The TMF arc is on the order 1024 m−3, and when the plasma temperature reaches 4.3 eV, the effects of thermal radiation cannot be ignored. The majority of the plasma from the cathode and anode undergo acceleration and then deceleration before finally intersecting at the center of the arc, creating an extreme value of the density and the pressure, where a large amount of kinetic energy is converted into internal energy. The arc will be bent and deflected under the action of the ampere force, and the deflection of Cu3+ is especially obvious. The TMF affects the collision strength of the jet in the intersection area and, thus, affects the ion density, in which the change of Cu2+ is dominant. The ionization–recombination process of ions is mainly determined by the electron temperature, which is affected by the arc current. As the current decreases, Cu1+ increases and Cu2+ and Cu3+ decrease, and the change in ionization rate is the main reason for the change in the proportion of each ionic component; the heat flux density to the anode and cathode is on the order of 1010 W/m2, which heats the front of the arc and ensures the stable movement of the arc. Meanwhile, due to the high ion number density, the ion heat flux accounts for the main part of the heat flux, and the anode exhibits a higher proportion of ion heat flux.