{"title":"Cover Picture: Contrib. Plasma Phys. 02/2025","authors":"","doi":"10.1002/ctpp.202590003","DOIUrl":"https://doi.org/10.1002/ctpp.202590003","url":null,"abstract":"<p>Normalized vector potential (<i>a<sub>y</sub></i>), the produced wakefield (<i>E<sub>x</sub></i>), the momentum (<i>p<sub>x</sub></i>) and the electron density (<i>n<sub>x</sub></i>) for hydrogen atoms density/pre-ionized plasma density <i>n</i><sub>0</sub> = 0.01<i>n<sub>cr</sub></i> at time 810 fs for the field-ionized plasma (panel a) and the pre-ionized plasma (panel b) and normalized vector potential variation <i>a</i><sub>0</sub> = 1 (in panels a1 and b1), <i>a</i><sub>0</sub> = 2 (in panels a2 and b2), and <i>a</i><sub>0</sub> = 3 (in panels a3 and b3). Fig. 4 of the paper by Elnaz Khalilzadeh et al. https://doi.org/10.1002/ctpp.202400022\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":"65 2","pages":""},"PeriodicalIF":1.3,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ctpp.202590003","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143431683","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}
Vivek Kumar Shukla, Saba Hussain, Monika Singh, Ram Kishor Singh
{"title":"Helical Electric Field-Assisted Circular Polarised Terahertz Wave Generation in Plasma by Beating of Two Lasers","authors":"Vivek Kumar Shukla, Saba Hussain, Monika Singh, Ram Kishor Singh","doi":"10.1002/ctpp.202400130","DOIUrl":"https://doi.org/10.1002/ctpp.202400130","url":null,"abstract":"<div>\u0000 \u0000 <p>We have studied the circular polarised Terahertz (THz) wave emission by mixing of two lasers in plasma when an externally applied helical structured electric field is present. A nonlinear transverse current density at difference frequency emerges on the accounts of ponderomotive nonlinearity. This occurs when the electrons moving under the influence of externally applied helical electric field, couples with the nonlinear plasma density at difference frequency. This transverse current density can be decomposed of two mutually perpendicular vector having equal amplitude and <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>π</mi>\u0000 <mo>/</mo>\u0000 <mn>2</mn>\u0000 </mrow>\u0000 <annotation>$$ pi /2 $$</annotation>\u0000 </semantics></math> phase shift, which drives a circular polarised coherent THz radiation. It turns out that conversion efficiency of THz radiation substantially depends on electron plasma frequency, mismatch phase, polarisation angle between laser beams and externally applied helical electric filed. Numerical simulations show that the conversion efficiency increases as THz frequency approach to plasma frequency.</p>\u0000 </div>","PeriodicalId":10700,"journal":{"name":"Contributions to Plasma Physics","volume":"65 5","pages":""},"PeriodicalIF":1.3,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144315129","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}
Dhyanjyoti D. Nath, Timothy R. Younkin, Jerome Guterl, Mark S. Shephard, Onkar Sahni
{"title":"A GPU-Accelerated 3D Unstructured Mesh Based Particle Tracking Code for Multi-Species Impurity Transport Simulation in Fusion Tokamaks","authors":"Dhyanjyoti D. Nath, Timothy R. Younkin, Jerome Guterl, Mark S. Shephard, Onkar Sahni","doi":"10.1002/ctpp.202400073","DOIUrl":"https://doi.org/10.1002/ctpp.202400073","url":null,"abstract":"<div>\u0000 \u0000 <p>This paper presents the multi-species global impurity transport capability developed in a GPU-accelerated fully 3D unstructured mesh-based code, GITRm, to simultaneously track multiple impurity species and handle interactions of these impurities with mixed-material surfaces. Different computational approaches to model particle-surface interaction or surface response have been developed and compared. Sheath electric field is taken into account by employing a fast distance-to-boundary calculation, which is carried out in parallel on distributed or partitioned meshes on multiple GPUs without the need for any inter-process communication during the simulation. Several example cases, including two for the DIII-D tokamak, that is, one with the SAS-V divertor and the other with the collector probes, are used to demonstrate the utility of the current multi-species capability. For the DIII-D probe case, the capability of GITRm to resolve the spatial distribution of particles in localized regions, such as diagnostic probes, within non-axisymmetric tokamak geometries is demonstrated. These simulations involve up to 320 million particles and utilize up to 48 GPUs.</p>\u0000 </div>","PeriodicalId":10700,"journal":{"name":"Contributions to Plasma Physics","volume":"65 5","pages":""},"PeriodicalIF":1.3,"publicationDate":"2025-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144315447","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}
Oussama Jdaini, Abdelhak Missaoui, Mohamed El Bojaddaini, Morad El Kaouini, Hassan Chatei
{"title":"Comparative Analysis of Plasma Sheath Characteristics in One-Dimensional and Three-Dimensional Velocity Spaces Governing Nonextensive Electron Density","authors":"Oussama Jdaini, Abdelhak Missaoui, Mohamed El Bojaddaini, Morad El Kaouini, Hassan Chatei","doi":"10.1002/ctpp.202400094","DOIUrl":"https://doi.org/10.1002/ctpp.202400094","url":null,"abstract":"<div>\u0000 \u0000 <p>In this study, we developed a model to explore the characteristics of a magnetized plasma sheath, containing positive ions, electrons, and neutral particles. The ions are described using a fluid model based on the continuity and momentum equations, while the electron distribution is analyzed using three cases: the Maxwell–Boltzmann distribution and the Tsallis distribution in both 1-D and 3-D velocity spaces. Applying the Sagdeev method, we established the modified Bohm sheath criterion to obtain the required ion velocity at the sheath entrance for all three cases. The lower Mach number limit for Bohm velocity modification depends on factors such as ion temperature, ionization frequency, collision frequency, magnetic field angle, nonextensive parameter <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>q</mi>\u0000 </mrow>\u0000 <annotation>$$ q $$</annotation>\u0000 </semantics></math>, and the velocity space governing the density of nonextensive electrons, independent of magnetic field magnitude. Additionally, the electron velocity distribution was analyzed for various <i>q</i>-values, revealing that in 3-D velocity space, the energy range is broad and extensive, while in 1-D velocity spaces, it is narrower and confined within the broader 3-D interval. We examined the influence of key parameters on sheath characteristics under the Maxwellian distribution, as well as in 1-D and 3-D velocity spaces for the Tsallis distribution. The results demonstrated significant differences between the three cases, showing that in the 3-D case, the sheath thickness expands more compared to the 1-D and the Maxwell–Boltzmann distribution. This underscores the significance of accounting for the dimensionality of velocity space when investigating plasma sheath phenomena. Such understanding is crucial for optimizing plasma-surface interactions in various applications.</p>\u0000 </div>","PeriodicalId":10700,"journal":{"name":"Contributions to Plasma Physics","volume":"65 5","pages":""},"PeriodicalIF":1.3,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144315393","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}
Stefan Andrei Irimiciuc, Sergii Chertopalov, Michal Novotny, Valentin Craciun, Jan Lancok
{"title":"Exploring Ion Dynamics in Laser-Produced Plasmas","authors":"Stefan Andrei Irimiciuc, Sergii Chertopalov, Michal Novotny, Valentin Craciun, Jan Lancok","doi":"10.1002/ctpp.202400139","DOIUrl":"https://doi.org/10.1002/ctpp.202400139","url":null,"abstract":"<p>Charged particle dynamics during transient plasma expansion have traditionally been studied within a consistent framework, supporting the advancement of applications like thin film deposition through pulsed laser ablation. However, reported plasma parameters often show inconsistencies, particularly in the relationship between ion mass and oscillation frequencies. Recent insights into charge current temporal traces have highlighted challenges in interpreting modulated probe currents. In this study, we present data on laser-produced plasma (LPP) from Co targets and explore additional phenomena that more accurately describe the behavior of highly energetic, rapidly diffusing LPP.</p>","PeriodicalId":10700,"journal":{"name":"Contributions to Plasma Physics","volume":"65 5","pages":""},"PeriodicalIF":1.3,"publicationDate":"2025-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ctpp.202400139","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144315214","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":"Particle-In-Cell (PIC) Simulations of Electron Focusing Heating Phenomena in Bilateral Ion Extraction Process","authors":"Xiaoyong Lu, Liangwei Liu","doi":"10.1002/ctpp.202400049","DOIUrl":"https://doi.org/10.1002/ctpp.202400049","url":null,"abstract":"<div>\u0000 \u0000 <p>Particle-in-cell simulations of bilateral ion extraction process are carried out for electron focusing heating phenomenon in this work. The mechanisms and characteristics of the negative heating effect are simulated and analyzed. Then influences of several factors on electron heating degree and ion collection ratio are provided numerically. Finally, relations between the negative heating effect and extraction instability phenomenon are discussed and an approach to mitigate the heating effect is given.</p>\u0000 </div>","PeriodicalId":10700,"journal":{"name":"Contributions to Plasma Physics","volume":"65 4","pages":""},"PeriodicalIF":1.3,"publicationDate":"2025-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143871677","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":"Coupled Electric-Thermal Damage Model for Lightning Strikes on Buried Pipeline","authors":"Xiao Jin, Pingping Rao, Weikang Feng, Jifei Cui, Sanjay Nimbalkar, Qingsheng Chen","doi":"10.1002/ctpp.202400104","DOIUrl":"https://doi.org/10.1002/ctpp.202400104","url":null,"abstract":"<div>\u0000 \u0000 <p>A coupled electrothermal damage theory model for pipelines is proposed to assess the failure behavior of buried pipelines under lightning strikes. This article considers local thermal nonequilibrium (LTNE) conditions in the soil–water porous medium and the nonlinear characteristics of lightning functions. The calculation results show that the proposed theoretical model has better applicability and accuracy compared with previous models. Parametric analysis shows that under lightning conditions of <i>I</i><sub>m</sub> = 20 kA and <i>T</i><sub>1</sub><i>/T</i><sub>2</sub> = 1.2/50 μs, the maximum local temperature of the soil around the pipeline can reach 2160 K, leading to pipeline breakdown. Metal pipelines are shown to be more effective in conducting charges, which alters the electric field distribution in the soil and impacts the formation of plasma channels. The half-peak value of the lightning waveform has a significant impact on pipeline breakdown, and its increase will increase the risk of pipeline breakdown gradually. When considering LTNE conditions, the change in the pipeline surface temperature becomes more pronounced. Under 8/30 and 8/40 μs lightning waveforms, the pipeline surface temperature is approximately 150 and 550 K higher, respectively, compared with the thermal equilibrium conditions. The thermal conductivity and porosity of backfill soil can also affect the thermal damage of lightning-struck pipelines. With clay filling, the highest pipeline surface temperature can reach 2590 K, while with fine sand and coarse sand, it is 1980 and 1510 K, respectively. The pipeline lightning disaster model proposed in this article has engineering significance for the investigation of pipeline lightning failure and disaster prevention mechanisms.</p>\u0000 </div>","PeriodicalId":10700,"journal":{"name":"Contributions to Plasma Physics","volume":"65 4","pages":""},"PeriodicalIF":1.3,"publicationDate":"2025-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143871454","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. 01/2025","authors":"","doi":"10.1002/ctpp.202590001","DOIUrl":"https://doi.org/10.1002/ctpp.202590001","url":null,"abstract":"<p>Plot of temperature inside the rock as a function of time at 70 kV. Fig. 8 of the paper by X. Zhu et al. https://onlinelibrary.wiley.com/doi/10.1002/ctpp.202400058<figure>\u0000 <div><picture>\u0000 <source></source></picture><p></p>\u0000 </div>\u0000 </figure></p>","PeriodicalId":10700,"journal":{"name":"Contributions to Plasma Physics","volume":"65 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2025-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ctpp.202590001","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143110402","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}
Sutapa Samanta, Rakesh Moulick, P. J. Bhuyan, B. J. Saikia
{"title":"Effect of Ion-Neutral Collisions on the Plasma Sheath in the Presence of Surface-Produced Negative Ions","authors":"Sutapa Samanta, Rakesh Moulick, P. J. Bhuyan, B. J. Saikia","doi":"10.1002/ctpp.202400088","DOIUrl":"https://doi.org/10.1002/ctpp.202400088","url":null,"abstract":"<p>The effect of ion-neutral collisions on the plasma sheath has been investigated for electronegative plasma in the presence of surface-produced negative ions. Such sheath structures are commonly found in the negative ion sources. It has been found that ion-neutral collisions reduce the ion velocity towards the sheath and consequently reduce the negative ion production from the surface. The space charge profile shows peak near the sheath edge in contrast to the common case where it has a peak near the wall. The fractional loss of the ions at the wall along with the ion impact energy is calculated.</p>","PeriodicalId":10700,"journal":{"name":"Contributions to Plasma Physics","volume":"65 4","pages":""},"PeriodicalIF":1.3,"publicationDate":"2024-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ctpp.202400088","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143871615","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}