Contributions to Plasma Physics最新文献

{"title":"Radially polarized femtosecond laser interaction with unmagnetized plasma slab and symmetric modes for enhanced terahertz field generation","authors":"Himank Sagar,&nbsp;Suresh C. Sharma","doi":"10.1002/ctpp.202400020","DOIUrl":"10.1002/ctpp.202400020","url":null,"abstract":"<p>We consider the excitation of terahertz (THz) electromagnetic fields by interaction of radially polarized laser pulses of diverse profiles with a homogenous plasma density slab. We utilize the properties of the laser pulse to generate THz fields in a plasma slab. It is shown that the radial ponderomotive force exerted by laser imparts an oscillatory velocity to plasma electrons and drives a nonlinear current in azimuthal direction exciting THz electromagnetic fields in the plasma slab. The dependence of the excited radial electric field and azimuthal magnetic field on axial and radial parameters of the plasmas lab, as well as on the slab thickness and laser pulse width size, is investigated. It is demonstrated that the terahertz fields are generated most efficiently with a frequency close to the plasma frequency. It is also shown that the intensity of the excited fields may be optimized and controlled by the plasma slab and laser pulse parameters. Rectangular-triangular, super-Gaussian, and sinusoidal lasers exhibit a significantly steeper radial gradient of ponderomotive potential in comparison with other laser profiles, and excite intense radial electric fields and generate azimuthal magnetic fields in plasma slab. The numerical results closely follow the scaling laws and match with previous experimental and simulation results.</p>","PeriodicalId":10700,"journal":{"name":"Contributions to Plasma Physics","volume":"64 10","pages":""},"PeriodicalIF":1.3,"publicationDate":"2024-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141372706","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":"First results of multi-fluid modeling of detached hydrogen plasmas in a linear plasma device using fluid code LINDA-NU","authors":"Kento Sugiura,&nbsp;Taichi Ido,&nbsp;Hirohiko Tanaka,&nbsp;Hiroki Natsume,&nbsp;Shota Masuda,&nbsp;Kazuo Hoshino,&nbsp;Keiji Sawada,&nbsp;Noriyasu Ohno","doi":"10.1002/ctpp.202300150","DOIUrl":"10.1002/ctpp.202300150","url":null,"abstract":"&lt;p&gt;In order to simulate hydrogen (H) plasma in the linear plasma device NAGDIS-II, we have modified the fluid code LINDA-NU to allow the simultaneous calculation of multiple ion species consisting of hydrogen atomic ions (&lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msup&gt;\u0000 &lt;mi&gt;H&lt;/mi&gt;\u0000 &lt;mo&gt;+&lt;/mo&gt;\u0000 &lt;/msup&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$$ {mathrm{H}}^{+} $$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;) and molecular ions (&lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msubsup&gt;\u0000 &lt;mi&gt;H&lt;/mi&gt;\u0000 &lt;mn&gt;2&lt;/mn&gt;\u0000 &lt;mo&gt;+&lt;/mo&gt;\u0000 &lt;/msubsup&gt;\u0000 &lt;mo&gt;,&lt;/mo&gt;\u0000 &lt;msubsup&gt;\u0000 &lt;mi&gt;H&lt;/mi&gt;\u0000 &lt;mn&gt;3&lt;/mn&gt;\u0000 &lt;mo&gt;+&lt;/mo&gt;\u0000 &lt;/msubsup&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$$ {mathrm{H}}_2^{+},{mathrm{H}}_3^{+} $$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;). In this simulation, H and &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;H&lt;/mi&gt;\u0000 &lt;mn&gt;2&lt;/mn&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$$ {mathrm{H}}_2 $$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; neutrals are assumed to be uniformly distributed in space in order to obtain initial qualitative results. The fraction of &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msubsup&gt;\u0000 &lt;mi&gt;H&lt;/mi&gt;\u0000 &lt;mn&gt;3&lt;/mn&gt;\u0000 &lt;mo&gt;+&lt;/mo&gt;\u0000 &lt;/msubsup&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$$ {mathrm{H}}_3^{+} $$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; ions increases as the &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;H&lt;/mi&gt;\u0000 &lt;mn&gt;2&lt;/mn&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$$ {mathrm{H}}_2 $$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; molecular density increases, and the recombination process between &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msubsup&gt;\u0000 &lt;mi&gt;H&lt;/mi&gt;\u0000 &lt;mn&gt;3&lt;/mn&gt;\u0000 &lt;mo&gt;+&lt;/mo&gt;\u0000 &lt;/msubsup&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$$ {mathrm{H}}_3^{+} $$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; and electrons is observed to reduce the particle flux to the target plate. With an increase in H density, the electron density increases due to the decrease in ion flow velocity due to the change exchange process, and the ele","PeriodicalId":10700,"journal":{"name":"Contributions to Plasma Physics","volume":"64 7-8","pages":""},"PeriodicalIF":1.3,"publicationDate":"2024-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ctpp.202300150","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141381018","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":"Role of ultrashort trapezoidal temporal pulse profile in laser wakefield acceleration in bubble regime","authors":"Sonu Kumar, Dhananjay K. Singh, Hitendra K. Malik","doi":"10.1002/ctpp.202300181","DOIUrl":"https://doi.org/10.1002/ctpp.202300181","url":null,"abstract":"A computational study is presented on laser wakefield acceleration (LWFA) in bubble regime with the use of ultrashort laser pulse propagating in an under‐dense plasma. The Particle‐In‐Cell simulations are performed to investigate the bubble wakefield acceleration of electrons realized by the incidence of an intense laser beam on cold, under‐dense plasma in two‐dimensional geometry. Different simulations are carried out and the results are compared for the beams with trapezoidal and Gaussian temporal pulse profiles having almost equal but slightly different energy contents. Focus is given to plasma density modulation, wakefield strength, electrons self‐injection, energy spectrum of accelerated electrons, the effect of an external longitudinal magnetic field and the study of pump depletion length and dephasing length in bubble regime with respect to these laser pulse profiles. Two limiting cases of the trapezoidal pulse, that is, triangular and rectangular pulses, are also discussed for better understanding of the role of steepness and plateau region in the laser pulse profile to the bubble wakefield acceleration. Since down ramp density gradient plays a crucial role for the generation of high‐quality electron beam in plasma wakefield acceleration as well as in LWFA, three different adjustments on the down ramp length determining three different density gradients are discussed for uncovering the role of trapezoidal laser pulse in LWFA.","PeriodicalId":10700,"journal":{"name":"Contributions to Plasma Physics","volume":"123 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141198439","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 of the influence of magnetic shear on the linear MHD instabilities in the pedestal of elongated divertor configurations using CLT code","authors":"Yuchen Xu,&nbsp;Shifeng Mao,&nbsp;Wenjin Chen,&nbsp;Zhiwei Ma,&nbsp;Minyou Ye","doi":"10.1002/ctpp.202300106","DOIUrl":"10.1002/ctpp.202300106","url":null,"abstract":"<p>Edge localized modes resulted from magnetohydrodynamic (MHD) instabilities in the pedestal region are a significant concern for future tokamaks. In this work, Ci-Liu-Ti (CLT), an MHD code in the three-dimensional toroidal geometry, is applied for the linear simulation of the ideal pedestal MHD instabilities. The simulations are performed for the experimental advanced superconducting tokamak-like elongated divertor configuration with large triangularity, which is generated by the high-accuracy free-boundary equilibrium solver (CLT-EQuilibrium, i.e., CLT-EQ) developed recently. The present work focuses on the influence of the magnetic shear, which is scanned by adjusting the pedestal current with a fixed pedestal pressure profile. As the pedestal current increases, both the local (<i>S</i>_local) and global (<i>S</i>_global) magnetic shear decrease. The ballooning mode is destabilized along with the decrease of <i>S</i>_local, and stabilized when <i>S</i>_local is negative for the whole region of bad curvature, which implies the access of the second stable region. Further increase of the pedestal current leads to the destabilization of the kink mode, which is stabilized again until <i>S</i>_global is negative at the location of significant gradient of current density. The simulated results are consistent with the findings in Radovanovic et al. Nucl. Fusion 62 (2022) 086004 and C. K. Sun et al. Phys. Plasmas 25 (2018) 082106, which indicates the availability of CLT in the linear simulation of the ideal pedestal instabilities.</p>","PeriodicalId":10700,"journal":{"name":"Contributions to Plasma Physics","volume":"64 7-8","pages":""},"PeriodicalIF":1.3,"publicationDate":"2024-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141108018","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":"Kinetic theory of weakly ionized plasma and electrolyte mixtures including Onsager matrix and frequency dispersion effects","authors":"W. Ebeling","doi":"10.1002/ctpp.202300161","DOIUrl":"10.1002/ctpp.202300161","url":null,"abstract":"<p>We summarize the method of hydrodynamic approximation for weakly ionized plasmas developed with Klimontovich in 1962 and give a generalization to many—component systems using Onsagers matrix theory and including dispersion effects. We develop the conductivity theory of complex plasma and electrolyte mixtures based on the model of charged hard spheres with given non-additive contact distances, including frequency-dependent electric fields. These generalizations are made with the aim to allow applications to complex natural systems as atmospheric plasmas and seawater. Finally, we give as an example a numerical calculation of the single ion conductivities of a six-component seawater model.</p>","PeriodicalId":10700,"journal":{"name":"Contributions to Plasma Physics","volume":"64 5","pages":""},"PeriodicalIF":1.3,"publicationDate":"2024-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ctpp.202300161","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141122019","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":"Issue Information: Contrib. Plasma Phys. 04/2024","authors":"","doi":"10.1002/ctpp.879","DOIUrl":"https://doi.org/10.1002/ctpp.879","url":null,"abstract":"","PeriodicalId":10700,"journal":{"name":"Contributions to Plasma Physics","volume":"64 4","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ctpp.879","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140949290","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":"Dynamics of electron capture in positron-hydrogen scattering under dense semi-classical plasmas","authors":"Kamalika Das,&nbsp;Netai Das,&nbsp;Arijit Ghoshal","doi":"10.1002/ctpp.202400012","DOIUrl":"10.1002/ctpp.202400012","url":null,"abstract":"<p>The scattering dynamics of electron capture in <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msup>\u0000 <mi>e</mi>\u0000 <mo>+</mo>\u0000 </msup>\u0000 </mrow>\u0000 <annotation>$$ {mathrm{e}}^{+} $$</annotation>\u0000 </semantics></math>-H(1 s) scattering under dense semi-classical plasma (DSCP) environments has been investigated theoretically. Coupled multi-channel two-body Lippmann-Schwinger equations have been solved by retaining <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msup>\u0000 <mi>e</mi>\u0000 <mo>+</mo>\u0000 </msup>\u0000 </mrow>\u0000 <annotation>$$ {mathrm{e}}^{+} $$</annotation>\u0000 </semantics></math>+H(1 s) and p + Ps(1 s) channels to calculate the cross sections (CS) of the electron capture process at intermediate and high incident energies. The effective interaction of the plasma charged particles is modelled by a pseudopotential which is a function of two parameters, namely the plasma screening strength and the de Broglie wavelength. A detailed study is made to explore the changes in the CSs of the above-mentioned process with respect to the variation in the plasma screening strength and de Broglie wavelength. Significant changes are found to take place, when the screening strength and the de Broglie wavelength are varied. Specifically, the sharp minimum in the differential CS moves toward the forward direction with increasing de Broglie wavelength at a given screening strength.</p>","PeriodicalId":10700,"journal":{"name":"Contributions to Plasma Physics","volume":"64 10","pages":""},"PeriodicalIF":1.3,"publicationDate":"2024-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140969468","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":"Plasma emission spectroscopy diagnosis of a direct current reverse-brush electrode discharge","authors":"Xingbao Lyu,&nbsp;Zhiyong Li,&nbsp;Yiqun Ma,&nbsp;Ying Wang,&nbsp;Chengxun Yuan,&nbsp;Anatoly Kudryavtsev,&nbsp;Zhongxiang Zhou","doi":"10.1002/ctpp.202400032","DOIUrl":"10.1002/ctpp.202400032","url":null,"abstract":"<p>In this work, emission spectra measurements from direct current (DC) reverse-brush discharge plasmas were used to elucidate the energy level transition processes corresponding to each spectral line based on the mechanism of emission spectrum generation. The axial distribution patterns of the spectral line intensity and the electron excitation temperature in the electrode gap and post-cathode space were systematically investigated. By comparing the acquired experimental results, it was observed that both the relative intensity of the plasma emission spectra and the electron excitation temperature in the electrode gap were higher than in the post-cathode space, while their axial distribution trends exhibited an initial increase followed by a decrease. Additionally, the impact of the discharge gas pressure, reverse-brush electrode thickness, and the number of electrode openings on the emission spectral line intensity and electron excitation temperature in the electrode gap were explored. Explanations for the underlying physical mechanisms were also provided.</p>","PeriodicalId":10700,"journal":{"name":"Contributions to Plasma Physics","volume":"64 10","pages":""},"PeriodicalIF":1.3,"publicationDate":"2024-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140970714","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. 04/2024","authors":"","doi":"10.1002/ctpp.880","DOIUrl":"https://doi.org/10.1002/ctpp.880","url":null,"abstract":"<p>(a) Electron current density, z-component; (b) Electric field intensity (V/m); filament line: electron flow. Fig.6 of the paper by Yiqun Ma et al. https://doi.org/10.1002/ctpp.202300169\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":"64 4","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ctpp.880","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140949289","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":"First SOLPS-ITER simulations of ASDEX Upgrade partially detached H-mode with boron impurity: The missing radiation at the outer strike-point region","authors":"S. O. Makarov,&nbsp;D. P. Coster,&nbsp;T. Gleiter,&nbsp;D. Brida,&nbsp;M. Muraca,&nbsp;R. Dux,&nbsp;P. David,&nbsp;B. Kurzan,&nbsp;X. Bonnin,&nbsp;M. O'Mullane,&nbsp;ASDEX Upgrade Team","doi":"10.1002/ctpp.202300139","DOIUrl":"10.1002/ctpp.202300139","url":null,"abstract":"<p>Partially detached H-modes are the baseline regime for the future ITER operation. The ASDEX Upgrade partially detached H-mode is modeled using the SOLPS-ITER code with drifts enabled and compared with experimental data. For the first time, boron (B) impurity is simulated in the Scrape-off layer (SOL) and divertor. A comparison between divertor diagnostics and discrepancies between Langmuir probe and Divertor Thomson scattering/Stark broadening diagnostic are discussed. In the modeling, experimental target profiles are reproduced if the experimental level of radiation in the SOL and divertor is achieved using nitrogen (N) impurity seeding. Bolometry measurements detect substantial radiation from the partially detached outer strike point. With B radiation, this maximum in bolometry data is reproduced in the modeling, which is not possible with N alone.</p>","PeriodicalId":10700,"journal":{"name":"Contributions to Plasma Physics","volume":"64 7-8","pages":""},"PeriodicalIF":1.3,"publicationDate":"2024-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ctpp.202300139","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140976882","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}