{"title":"Relationship between cosmic ray intensity and Earth's magnetic field: Cross-wavelet analysis during intense and moderate geomagnetic storms","authors":"Chali Idosa Uga, Sujan Prasad Gautam, Binod Adhikari, Ashok Silwal, Ashutosh Giri","doi":"10.1063/5.0201135","DOIUrl":"https://doi.org/10.1063/5.0201135","url":null,"abstract":"This study investigated the relationship between the cosmic ray intensity (CRI) and the horizontal component of Earth's magnetic field (dH) during two intense geomagnetic storms that occurred on September 8, 2017, and August 26, 2018, and a moderate storm on February 18, 2020 over three stations: IRKT, YKTK, and HRMS. The findings of this study indicate that the CRI and dH do not exhibit a simple association over each station. A significant decrease in CRI and dH was seen during the intense geomagnetic storm on September 8, 2017, over all stations as compared to the other two storm events. The decrease was more pronounced over the YKTK station, which has low cutoff rigidity (1.65 GV), than the HRMS (4.58 GV) and IRKT (3.64 GV) stations with high cutoff rigidity. Furthermore, the cross-wavelet analysis reveals that the relationship between CRI and dH varies with the strength of the storm, the location, and the cutoff rigidity of the station.","PeriodicalId":20175,"journal":{"name":"Physics of Plasmas","volume":"185 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142227587","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Trapping and detrapping of electrons in a typical DC glow discharge plasma under double layer condition","authors":"Thangjam Rishikanta Singh, Sneha Latha Kommuguri, Suraj Kumar Sinha","doi":"10.1063/5.0222639","DOIUrl":"https://doi.org/10.1063/5.0222639","url":null,"abstract":"Observation of a dip in plasma density with the rise of ion plasma waves demonstrates the process of detrapping electrons under the double-layer conditions in a DC glow discharge plasma. This study presents an experimental observation of self-excitation and interplay between electron and ion plasma waves when a high positive DC voltage (Vp∼+100 V) is applied to a planar probe immersed in plasma. For lower voltages (Vp∼+5 V), the electron sheath forms on the surface of the probe; however, for sufficiently high applied voltage, plasma could not supply the sufficient number of electrons to shield it from penetrating deep into the plasma. Therefore, the electron-deficient sheath attracts plasma electrons toward the probe, resulting in the excitation of plasma waves and the formation of double layers. Low energy streaming electrons get trapped in the double layers potential step. On ionization of background neutrals, trapped electrons get detrapped. It results in the excitation of ion waves and damping of electron plasma waves. The wavelet analysis of the observed floating potential fluctuations exhibits the interplay between electron and ion plasma waves. The trapping of electrons causes the excitation of electron plasma waves, and detrapping results in the excitation of ion plasma waves as overall electron density dips. It provides new insight into the nonlinear effects of the wave–wave interaction, the onset of Buneman instability, and streaming instability under the double-layer condition.","PeriodicalId":20175,"journal":{"name":"Physics of Plasmas","volume":"72 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142221817","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Modifications to Swisdak (2013)'s rejection sampling algorithm for a Maxwell–Jüttner distribution in particle simulations","authors":"Seiji Zenitani","doi":"10.1063/5.0226859","DOIUrl":"https://doi.org/10.1063/5.0226859","url":null,"abstract":"Modifications to Swisdak's [Phys. Plasmas 20, 062110 (2013)] rejection sampling algorithm for drawing a Maxwell–Jüttner distribution in particle simulations are presented. Handy approximations for e-folding points and a linear slope in the envelope function are proposed, to make the algorithm self-contained and more efficient.","PeriodicalId":20175,"journal":{"name":"Physics of Plasmas","volume":"5 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142221860","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Interaction mechanism of cold atmospheric plasmas and fusion peptides of spike protein in SARS-CoV-2 revealed by reactive molecular dynamics simulation","authors":"Yang Chen, Zhao-Nan Chai, Yuan-Tao Zhang","doi":"10.1063/5.0216072","DOIUrl":"https://doi.org/10.1063/5.0216072","url":null,"abstract":"Despite the conclusion of the COVID-19 pandemic, the coronavirus-killing ability of cold atmospheric plasma (CAP) remains impressive, and investigations into its underlying mechanisms are still ongoing. The fusion peptide (FP) is a crucial site of membrane fusion and toxicity exerted by the S-protein in severe acute respiratory syndrome CoV-2 (SARS-CoV-2). In this study, reactive molecular dynamics simulations were performed to investigate the interaction mechanisms of FP and reactive oxygen species (ROS). The simulation results show that the given ROS (O atoms and OH radicals as examples) can destroy hydrophobic residues, negatively charged acidic residues, and peptide bonds through structurally altering essential sites. Furthermore, the reaction typically initiates from the H-abstraction reaction, followed by various types of oxidative modifications such as dehydrogenation, hydroxylation, carbonylation, cyclogenesis, ring cleavage, and decarboxylation, which are consistent with the experimental findings made on peptides. Therefore, it can be predicted that the membrane fusion ability of FP and the toxicity of SARS-CoV-2 will be reduced, with CAP functioning as a bactericidal disinfectant. The dose effects were also investigated, providing experimental guidance for the optimization of CAP. In this study, the interaction processes of FP and CAP are explored by revealing the chemical pathways and final reaction products from the computational data, thus providing a fundamental understanding of the mechanisms for inactivating SARS-CoV-2 by CAP.","PeriodicalId":20175,"journal":{"name":"Physics of Plasmas","volume":"40 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142221856","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
L. A. Bakaleinikov, V. I. Kuznetsov, E. Yu. Flegontova, D. P. Barsukov, I. K. Morozov
{"title":"Steady state stability features of the electron–positron plasma diode in a mode with particle reflection from potential extrema","authors":"L. A. Bakaleinikov, V. I. Kuznetsov, E. Yu. Flegontova, D. P. Barsukov, I. K. Morozov","doi":"10.1063/5.0225861","DOIUrl":"https://doi.org/10.1063/5.0225861","url":null,"abstract":"Steady state stability features of a diode with electrons and positrons entering from opposite boundaries and moving without collisions in plasma are numerically studied. The most complex regime when charged particles are reflected from potential barriers is considered. This problem arises, in particular, when modeling pulsar diodes. A small perturbation evolution is studied. It has been established that at the initial stage of the process the perturbation amplitude changes in time according to an exponential law. It is shown that stationary solutions with a potential barrier for electrons located near the electron-emitting electrode and a potential barrier for positrons located near the opposite electrode are stable when the inter-electrode distance is below a certain threshold. As the inter-electrode distance increases, the solutions become unstable. Solutions of another type when barriers reflecting particles are located in the opposite to the emitting electrode parts of the gap are also studied. However, these solutions turned out to be unstable.","PeriodicalId":20175,"journal":{"name":"Physics of Plasmas","volume":"60 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142221857","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
Num Prasad Acharya, Suresh Basnet, Amar P. Misra, Raju Khanal
{"title":"Dust–ion–acoustic damped solitary waves and shocks in laboratory and Saturn's E-ring magnetized nonthermal dusty plasmas with anisotropic ion pressure and dust-charge fluctuation","authors":"Num Prasad Acharya, Suresh Basnet, Amar P. Misra, Raju Khanal","doi":"10.1063/5.0220030","DOIUrl":"https://doi.org/10.1063/5.0220030","url":null,"abstract":"We study the oblique propagation of weakly nonlinear dust–ion–acoustic (DIA) solitary waves (SWs) and shocks in collisional magnetized nonthermal dusty plasmas that are relevant in laboratory and space (Saturn's E-ring) environments. We consider plasmas to be composed of q-nonextensive hot electrons, thermal positive ions, and immobile negatively charged dust grains immersed in a static magnetic field and take into account the effects of ion creation (source), ion loss (sink), ion–neutral and ion–dust collisions, anisotropic ion pressure, and dust-charge fluctuations on the evolution of small-amplitude SWs and shocks. The ion–neutral collision enhancement equilibrium dust-charge number is self-consistently determined using Newton–Raphson method. We found that in laboratory dusty plasmas with adiabatic dust-charge variation [i.e., when the dust charging frequency (νch) is much higher than the dust–plasma oscillation frequency (ωpd)], the DIA solitary waves (DIASWs) get damped by the effects of the ion–dust and ion–neutral collisions, whereas the ion creation and ion loss lead to the amplification of solitary waves, and they appear as only compressive types with positive potential. On the other hand, in Saturn's E-ring plasmas, where the collisional and ion creation or ion loss effects are insignificant, the non-adiabaticity of dust-charge variation can give rise to the evolution of either damped DIASWs or DIA shocks, depending on the smallness of the ratios νch/ωpd or ωpd/νch, respectively. Furthermore, two critical values of the nonextensive parameter q exist, below (or above) which, the DIASWs and shocks can appear as rarefactive (or compressive) types. The characteristics of DIASWs and shocks are also analyzed numerically for parameters relevant to the laboratory and Saturn's E-ring plasmas.","PeriodicalId":20175,"journal":{"name":"Physics of Plasmas","volume":"175 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142221855","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
Swadesh M. Mahajan, Prerana Sharma, Manasvi Lingam
{"title":"Hall MHD waves: A fundamental departure from their MHD counterparts","authors":"Swadesh M. Mahajan, Prerana Sharma, Manasvi Lingam","doi":"10.1063/5.0227375","DOIUrl":"https://doi.org/10.1063/5.0227375","url":null,"abstract":"It is demonstrated through a succinct derivation as to how the linear waves in Hall magnetohydrodynamics (HMHD) constitute a fundamental departure from the standard MHD waves. Apart from modifying the conventional MHD spectrum, the Hall current induces a distinct and new branch consisting of purely circularly polarized waves that may become the representative shear waves.","PeriodicalId":20175,"journal":{"name":"Physics of Plasmas","volume":"433 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142221854","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
Hee-Jung Yeom, Gwang-Seok Chae, Min Young Yoon, Wooram Kim, Jae-Heon Lee, Jun-Hyung Park, Chan-Woo Park, Jung-Hyung Kim, Hyo-Chang Lee
{"title":"Effect of radiofrequency bias power on transmission spectrum of flat-cutoff sensor in inductively coupled plasma","authors":"Hee-Jung Yeom, Gwang-Seok Chae, Min Young Yoon, Wooram Kim, Jae-Heon Lee, Jun-Hyung Park, Chan-Woo Park, Jung-Hyung Kim, Hyo-Chang Lee","doi":"10.1063/5.0221016","DOIUrl":"https://doi.org/10.1063/5.0221016","url":null,"abstract":"Real-time monitoring of plasma parameters at the wafer plane is important because it significantly affects the processing results, yield enhancement, and device integrity of plasma processing. Various plasma diagnostic sensors, including those embedded in a chamber wall and on-wafer sensors, such as flat-cutoff sensors, have been developed for plasma measurements. However, to measure the plasma density on the wafer surface in real-time when processing plasma with bias power, such as in the semiconductor etching process, one must analyze the transmission spectrum of the flat-cutoff sensor in an environment with bias power applied. In this study, the transmission-spectrum and measured plasma-density characteristics of an electrode-embedded flat-cutoff sensor are analyzed via electromagnetic simulations and experiments under applied bias power. Our findings indicate that the flat-cutoff sensor accurately measures the plasma density, which is equivalent to the input plasma density under low bias power. Conversely, under high bias power, the plasma density measured by the sensor is lower than the input plasma density. Also, a thick-sheath layer is formed owing to the high bias power, which may complicate the measurement of plasma parameters using the flat-cutoff sensor. Plasma diagnostics using a flat-cutoff sensor in thick-sheath environments can be achieved by optimizing the flat-cutoff sensor structure. Our findings can enhance the analysis of plasma parameters on-wafer surfaces in processing environments with bias power applied.","PeriodicalId":20175,"journal":{"name":"Physics of Plasmas","volume":"62 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142221816","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
M. Chernyshova, K. Malinowski, K. Mikszuta-Michalik, S. Jabłoński, M. Jagielski
{"title":"Conceptual research on meeting tomographic reconstruction and measurement accuracy requirements: Key factors in the development of a radiated power diagnostics for DEMO","authors":"M. Chernyshova, K. Malinowski, K. Mikszuta-Michalik, S. Jabłoński, M. Jagielski","doi":"10.1063/5.0209330","DOIUrl":"https://doi.org/10.1063/5.0209330","url":null,"abstract":"This work addresses the development of diagnostics for core plasma radiated power and soft x-ray intensity measurements, which will be useful in future fusion reactors to ensure reliable plasma control (by monitoring the power loss across the separatrix) in accordance with the DEMO control requirements. For this purpose, we look into the development of such a detection system that will provide the required information via soft x-ray diagnostics. The target photon range for such a detecting system is considered to be 3–50 keV. The aspects of the development have included detailed diagnostics design, physics, engineering and integration studies, as well as an investigation into the feasibility and performance of the diagnostics and its components. The development is currently in the design phase. Nevertheless, the answer is already needed regarding the fulfillment of system requirements. In order to monitor the power crossing the separatrix, a precise estimation of the plasma radiation is needed to maintain the high-efficiency plasma. This requires strict measurement accuracy criteria, with 3% accuracy margin for the core plasma radiated power estimate and 5% noise for a single measurement of a single detector within the detector array. Here, an initial estimation of the detecting system's accuracy was provided based on an analysis of both the tomography reconstruction and detector measurement capabilities. The optimal number of lines of sight for tomography reconstruction was found for the considered plasma field of view. Additionally, the initial concept for a photon-sensitive chamber of the detecting system was developed. This allowed for the assessment of the predicted measurement accuracy of the detector for horizontal and vertical lines of sight.","PeriodicalId":20175,"journal":{"name":"Physics of Plasmas","volume":"14 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142221858","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Three-dimensional plasmoid-mediated reconnection and turbulence in Hall magnetohydrodynamics","authors":"Yi-Min Huang, Amitava Bhattacharjee","doi":"10.1063/5.0216561","DOIUrl":"https://doi.org/10.1063/5.0216561","url":null,"abstract":"Plasmoid instability accelerates reconnection in collisional plasmas by transforming a laminar reconnection layer into numerous plasmoids connected by secondary current sheets in two dimensions (2D) and by fostering self-generated turbulent reconnection in three dimensions (3D). In large-scale astrophysical and space systems, plasmoid instability likely initiates in the collisional regime but may transition into the collisionless regime as the fragmentation of the current sheet progresses toward kinetic scales. Hall magnetohydrodynamics (MHD) models are widely regarded as a simplified yet effective representation of the transition from collisional to collisionless reconnection. However, plasmoid instability in 2D Hall MHD simulations often leads to a single-X-line reconnection configuration, which significantly differs from fully kinetic particle-in-cell simulation results. This study shows that single-X-line reconnection is less likely to occur in 3D compared to 2D. Moreover, depending on the Lundquist number and the ratio between the system size and the kinetic scale, Hall MHD can also realize 3D self-generated turbulent reconnection. We analyze the features of the self-generated turbulent state, including the energy power spectra and the scale dependence of turbulent eddy anisotropy.","PeriodicalId":20175,"journal":{"name":"Physics of Plasmas","volume":"284 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142221859","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}