Contributions to Plasma Physics最新文献

{"title":"Non-Extensive Plasma Sheath Dynamics: Effects of Negative Ions and Secondary Electron Emission","authors":"Zakariyae El Ankouri, Mohamed El Bojaddaini, Morad El Kaouini, Abdelhak Missaoui, Hassan Chatei","doi":"10.1002/ctpp.70058","DOIUrl":"https://doi.org/10.1002/ctpp.70058","url":null,"abstract":"<div>\u0000 \u0000 <p>This paper investigates the influence of negative ions and secondary electron emission on plasma sheath formation and structure. The system consists of primary electrons following the non-extensive distribution, negative ions described by the Maxwell–Boltzmann distribution, and secondary electrons and positive ions modeled as a cold fluid. Using the Sagdeev potential approach, a generalized Bohm criterion <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>M</mi>\u0000 </mrow>\u0000 <annotation>$$ M $$</annotation>\u0000 </semantics></math> is derived for both extensive <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mrow>\u0000 <mo>(</mo>\u0000 <mrow>\u0000 <mi>q</mi>\u0000 <mo>=</mo>\u0000 <mn>1</mn>\u0000 </mrow>\u0000 <mo>)</mo>\u0000 </mrow>\u0000 </mrow>\u0000 <annotation>$$ left(q=1right) $$</annotation>\u0000 </semantics></math> and non-extensive <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mrow>\u0000 <mo>(</mo>\u0000 <mrow>\u0000 <mi>q</mi>\u0000 <mo>≠</mo>\u0000 <mn>1</mn>\u0000 </mrow>\u0000 <mo>)</mo>\u0000 </mrow>\u0000 </mrow>\u0000 <annotation>$$ left(qne 1right) $$</annotation>\u0000 </semantics></math> regimes. The floating potential <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mi>ψ</mi>\u0000 <mi>w</mi>\u0000 </msub>\u0000 </mrow>\u0000 <annotation>$$ {psi}_w $$</annotation>\u0000 </semantics></math> is determined through flux conservation at the wall, while the secondary electron density at the sheath edge <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mi>N</mi>\u0000 <mrow>\u0000 <mi>s</mi>\u0000 <mn>0</mn>\u0000 </mrow>\u0000 </msub>\u0000 </mrow>\u0000 <annotation>$$ {N}_{s0} $$</annotation>\u0000 </semantics></math> is obtained under the quasi-neutrality assumption. The results highlight the critical role of key parameters, including electronegativity <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>B</mi>\u0000 </mrow>\u0000 <annotation>$$ B $$</annotation>\u0000 </semantics></math>, the secondary electron emission coefficient <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>γ</mi>\u0000 </mrow>\u0000 <annotation>$$ gamma $$</annotation>\u0000 </semantics></mat","PeriodicalId":10700,"journal":{"name":"Contributions to Plasma Physics","volume":"66 3","pages":""},"PeriodicalIF":1.5,"publicationDate":"2026-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147562923","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Face-to-Face Interactions of Breathers and Solitons in a Non-Maxwellian Plasma With the Critical Composition of Electron Beam","authors":"Prasanta Chatterjee,&nbsp;Laxmikanta Mandi,&nbsp;Jayshree Mondal","doi":"10.1002/ctpp.70067","DOIUrl":"https://doi.org/10.1002/ctpp.70067","url":null,"abstract":"<div>\u0000 \u0000 <p>In the present investigation, the collisions of weakly nonlinear wave structures in an unmagnetized plasma comprising inertial ions, Vasyliunas–Cairns (VC) distributed electrons, and electron beams are analyzed based on experimental data. The study focuses on face-to-face collisions involving soliton–soliton, soliton–breather, and breather–breather interactions. To carry out this analysis, the extended Poincaré–Lighthill–Kuo (PLK) reductive perturbation method is employed, leading to the derivation of two coupled Korteweg–de Vries (KdV) equations. At a critical value of the number density ratio, two coupled modified Korteweg–de Vries (mKdV) equations are used to study soliton–soliton, soliton–breather, and breather–breather interactions of the ion-acoustic wave. The effects of various plasma parameters—namely, the superthermality of electrons (<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mi>κ</mi>\u0000 <mi>e</mi>\u0000 </msub>\u0000 </mrow>\u0000 <annotation>$$ {kappa}_e $$</annotation>\u0000 </semantics></math>), the nonthermality of electrons (<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mi>α</mi>\u0000 <mn>1</mn>\u0000 </msub>\u0000 </mrow>\u0000 <annotation>$$ {alpha}_1 $$</annotation>\u0000 </semantics></math>), and the electron beam-to-ion density ratio (<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mi>ρ</mi>\u0000 <mi>b</mi>\u0000 </msub>\u0000 </mrow>\u0000 <annotation>$$ {rho}_b $$</annotation>\u0000 </semantics></math>) at equilibrium—on the colliding soliton profiles are examined. The plasma parameter values used in the analysis are taken from the interplanetary space environment.</p>\u0000 </div>","PeriodicalId":10700,"journal":{"name":"Contributions to Plasma Physics","volume":"66 3","pages":""},"PeriodicalIF":1.5,"publicationDate":"2026-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147568906","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Issue Information: Contrib. Plasma Phys. 03/2026","authors":"","doi":"10.1002/ctpp.70107","DOIUrl":"https://doi.org/10.1002/ctpp.70107","url":null,"abstract":"","PeriodicalId":10700,"journal":{"name":"Contributions to Plasma Physics","volume":"66 3","pages":""},"PeriodicalIF":1.5,"publicationDate":"2026-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ctpp.70107","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147566280","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of Kaniadakis Distributed Electrons on the Dust Acoustic Waves in a Charge Varying Dusty Plasma","authors":"Mustapha Bacha","doi":"10.1002/ctpp.70061","DOIUrl":"https://doi.org/10.1002/ctpp.70061","url":null,"abstract":"<div>\u0000 <p>The propagation of dust acoustic waves, both solitary and shock waves of arbitrary amplitude, is revisited for the first time in a dusty plasma composed of Kaniadakis-distributed electrons, positive ions, and dust grains with variable charge. The <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>κ</mi>\u0000 </mrow>\u0000 <annotation>$$ kappa $$</annotation>\u0000 </semantics></math>-generalized electron charging current is derived using the orbit-motion-limited (OML) theory. It is observed that the Kaniadakis electron distribution plays a significant role in shaping the behavior of variable-charge solitary waves. Specifically, in the adiabatic regime, this distribution results in solitary structures that are less sharply peaked and promotes enhanced electron collection by the dust grains, or equivalently, suppresses the collection of positive ions. In the non-adiabatic regime, the system supports dissipative shock waves, and the presence of <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>κ</mi>\u0000 </mrow>\u0000 <annotation>$$ kappa $$</annotation>\u0000 </semantics></math>-distributed electrons facilitates a transition in the wave profile from oscillatory to monotonic behavior.</p>\u0000 </div>","PeriodicalId":10700,"journal":{"name":"Contributions to Plasma Physics","volume":"66 3","pages":""},"PeriodicalIF":1.5,"publicationDate":"2026-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147566876","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assessing the Impact of Plasma Density, Sputtering, and E × B Drift on Divertor Plates Detachment in a Small-Size Tokamak","authors":"Fathy B. Diab,&nbsp;Amr H. Bekheit,&nbsp;Mohamed A. Abd Al-Halim,&nbsp;Kamal M. Ahmed","doi":"10.1002/ctpp.70057","DOIUrl":"https://doi.org/10.1002/ctpp.70057","url":null,"abstract":"<div>\u0000 \u0000 <p>The edge transport barrier (ETB) on small-size divertor tokamak (SSDT) causes a detached regime. The B2SOLPS5.02D multifluid code simulates the drifts on edge plasma in the detached divertor regime. In SSDT, two case studies: (i) the core plasma density had been adjusted (4, 6, 8 × 10¹⁹ and 1 × 10²⁰ m⁻³) with a set sputtering coefficient of 1.1%, and (ii) the sputtering yield was changed (0.4%, 0.6%, 0.8%, 1% and 1.2%) with a constant core plasma density of 4 × 10¹⁹ m⁻³ have been conducted. The 2D simulations show that, during transitioning to detached conditions in SSDT with ETB formation mode with forward field configurations, the low field side (LFS) divertor target heat flux is directly impacted by the cross-field drifts and flows. The simulation demonstrated that, concerning the electron temperature, the two divertor plates are detached at higher density while at lower density, the HFS plate is considered as ‘attached plate’. Additionally, as the core plasma density increases, the peaks of poloidal electron heat flux of the HFS plate were increased insignificantly, while it is strongly increased in the LFS plate. Moreover, as the core density is raised into the detached domain, some characteristics of the detachment processes, such as a roll-over in the ion-saturation current and a cliff in the electron temperature nearby the divertor plates, have been observed. Involving of the carbon sputtering in the detachment cliff formation is also established. Finally, a correlation is found between the development of a detached cliff and the rise in the SOL width.</p>\u0000 </div>","PeriodicalId":10700,"journal":{"name":"Contributions to Plasma Physics","volume":"66 2","pages":""},"PeriodicalIF":1.5,"publicationDate":"2026-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147569729","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Numerical Study on the DBD Discharge Characteristics of Soil Particles in CO2 Atmosphere","authors":"Dan Li,&nbsp;Junyu Wang,&nbsp;Huayuan Liu,&nbsp;Juhui Chen,&nbsp;Baowei Sun,&nbsp;Xianli Liu,&nbsp;Michael Zhurakov,&nbsp;Siarhei Lapatsin,&nbsp;Wenrui Jiang","doi":"10.1002/ctpp.70051","DOIUrl":"https://doi.org/10.1002/ctpp.70051","url":null,"abstract":"<div>\u0000 \u0000 <p>To better understand the discharge mechanism and pollutant degradation process of dielectric barrier discharge (DBD) in soil under a CO₂ atmosphere, a mathematical model and theoretical framework have been established. Based on a discharge kinetics model, this study simulates the discharge characteristics of a DBD soil system, and the simulation results show strong agreement with experimental data. The results reveal that regions of high electron density on the surfaces of soil particles induce more micro-discharges, thereby enhancing discharge efficiency. Significant changes in electron temperature on particle surfaces promote the generation of reactive species, which accelerate pollutant degradation. The electric field evolves from an initially uniform weak field to a localized strong field, which improves CO₂ ionization. A higher dielectric constant of soil particles improves electric field uniformity and expands the effective discharge area. At a peak voltage of 24 kV, electron density reaches an optimal level, while excessively high or low voltages lead to reduced performance. After CO₂ plasma enters the soil, long-lived reactive species such as O₃, O, CO₂(e₁), and CO₂(v₁) play key roles in pollutant degradation.</p>\u0000 </div>","PeriodicalId":10700,"journal":{"name":"Contributions to Plasma Physics","volume":"66 2","pages":""},"PeriodicalIF":1.5,"publicationDate":"2026-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147569005","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Influence of Non-Extensive Electrons on the Characteristics of the Space-Charge Sheath in Tonks-Langmuir Kinetic Model","authors":"Farinaz Donyapasand Kojabad,&nbsp;Abdolrasoul Esfandyari Kalejahi,&nbsp;Mohammad Ali Mohammadi Dorbash","doi":"10.1002/ctpp.70047","DOIUrl":"https://doi.org/10.1002/ctpp.70047","url":null,"abstract":"<div>\u0000 \u0000 <p>The purpose of this paper is to investigate the Tonks-Langmuir model by assuming that the electrons obey the <i>q</i>- non-extensive distribution. The plasma equation is analytically solved. It is revealed that the quasi-neutrality length of the glow discharge exceeds with the decrement of the non-extensive parameter <i>q</i>. In the extensive limiting case (<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>q</mi>\u0000 <mo>→</mo>\u0000 <mn>1</mn>\u0000 </mrow>\u0000 <annotation>$$ qto 1 $$</annotation>\u0000 </semantics></math> i.e., Maxwellian case) the previously well-known results are recovered. Moreover, by evaluating the mean inverse kinetic energy of ions, it is illustrated that the kinetic Bohm criterion does not represent an inherent property of the collision- and ionization-free one-dimensional space-charge sheaths in the case of non-extensive electron distribution, contrary to the Maxwellian one. Finally, the plasma-sheath equation is numerically solved in the case of non-extensive electron distribution. It is found that the decrement of <i>q</i> gives rise to the increment of the wall potential value and sheath thickness for super-thermal electron distribution <i>q</i> &lt; 1. On the other hand, it is observed that the wall potential value and the sheath thickness decrease as q increases for sub-thermal electron distribution <i>q</i> &gt; 1. On this basis, it is concluded that the characteristics of the space-charge sheath in the low-pressure plane symmetric discharge depend on the electron non-extensive parameter <i>q</i>. This is in agreement with the prior practical measurements on the ion sheath formed around a non-extensive single electric probe in plasma.</p>\u0000 </div>","PeriodicalId":10700,"journal":{"name":"Contributions to Plasma Physics","volume":"66 2","pages":""},"PeriodicalIF":1.5,"publicationDate":"2026-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147563569","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study on the Effects of Magnetic Null Point Position on Discharge Structure and Performance in a Double-Stage Hall Thruster","authors":"Long Chen,&nbsp;Xintong Liu,&nbsp;Miao Liu,&nbsp;Ping Duan,&nbsp;Weifu Gao,&nbsp;Xuesong Xu,&nbsp;Wanxin Cui,&nbsp;Jie Feng","doi":"10.1002/ctpp.70054","DOIUrl":"https://doi.org/10.1002/ctpp.70054","url":null,"abstract":"<div>\u0000 \u0000 <p>The magnetic configuration critically influences the plasma structure and discharge performance of Hall thrusters. However, the effect of magnetic null points on the performance of double-stage Hall thrusters has not been systematically investigated. In this study, we numerically examine how the spatial location of the second magnetic null point near the channel exit affects plasma behavior and propulsion performance, both in the axial and radial directions. A 2D-3V PIC/MCC model is developed to simulate the discharge process under different magnetic configurations. The results show that magnetic null point location significantly influences magnetic topology, potential distribution, and the spatial coupling between the ionization and acceleration regions. Optimal thrust and efficiency are achieved when the magnetic null point is axially aligned with the intermediate electrode and radially positioned near the channel wall, forming asymmetric magnetic fields that promote electron energization and localized ionization. In contrast, a centrally located magnetic null point increases magnetic resistance near the walls, disrupts the dual-region structure, and causes inefficient energy deposition of the electrons. These findings provide new physical insight into magnetic topology control and offer guidance for optimizing field configurations in future double-stage Hall thruster designs to improve energy utilization and propulsion efficiency.</p>\u0000 </div>","PeriodicalId":10700,"journal":{"name":"Contributions to Plasma Physics","volume":"66 2","pages":""},"PeriodicalIF":1.5,"publicationDate":"2026-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147567484","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Low-Temperature Plasma Inhibits Melanoma Growth via Enhanced T-Cell Immunity","authors":"Na Liu,&nbsp;Xiangni Wang,&nbsp;Xiying Wang,&nbsp;Jinren Liu,&nbsp;Yixin Cui,&nbsp;Guimin Xu,&nbsp;Jiajia Lu,&nbsp;Chuchu Kang,&nbsp;Zhirou He,&nbsp;Yulin Xu,&nbsp;Rongrong Li,&nbsp;Xingmin Shi,&nbsp;Xili Wu,&nbsp;Peng An","doi":"10.1002/ctpp.70046","DOIUrl":"https://doi.org/10.1002/ctpp.70046","url":null,"abstract":"<div>\u0000 \u0000 <p>Since the antitumor effect of low-temperature plasma (LTP) was first discovered in 2007, efforts have been devoted to investigating its therapeutic effects in various tumors. LTP has been shown to induce diverse cell death pathways in a dose-dependent manner, modulate immunogenic responses, and suppress tumor invasion and metastasis. However, the precise mechanisms underlying these effects remain poorly elucidated. In this study, we investigated the role of LTP in melanoma growth inhibition. Our findings demonstrate that LTP suppresses melanoma progression by enhancing T-cell-mediated immunity. Mechanistic investigations suggest that direct LTP treatment modulates cytokine expression in regulatory T cells (Tregs) and CD8⁺ T cells, while indirect LTP treatment regulates cytokine levels and inhibits the signal transducer and activator of transcription 3 (STAT3) signaling pathway, contributing to its antitumor activity. These results not only provide a potential novel strategy for melanoma treatment but also advance our understanding of the interplay between LTP and the immune system.</p>\u0000 </div>","PeriodicalId":10700,"journal":{"name":"Contributions to Plasma Physics","volume":"66 2","pages":""},"PeriodicalIF":1.5,"publicationDate":"2026-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147570373","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cover Picture: Contrib. Plasma Phys. 02/2026","authors":"","doi":"10.1002/ctpp.70088","DOIUrl":"https://doi.org/10.1002/ctpp.70088","url":null,"abstract":"<p>Schematic diagram of thruster structure. (a) The schematic diagram of internal cathode thruster. (b) The picture of the thruster. Fig. 2 of the paper by Yi Li et al.\u0000\u0000 <figure>\u0000 <div><picture>\u0000 <source></source></picture><p></p>\u0000 </div>\u0000 </figure></p>","PeriodicalId":10700,"journal":{"name":"Contributions to Plasma Physics","volume":"66 2","pages":""},"PeriodicalIF":1.5,"publicationDate":"2026-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ctpp.70088","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147564891","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}