-
Temperature and density dependence of Kr L-shell spectrum in hot dense plasmas Phys. Plasmas (IF 2.2) Pub Date : 2024-03-18 E. Gallardo-Diaz, R. C. Mancini, K. R. Carpenter, P. Adrian, J. Frenje, R. Florido
Kr L-shell spectroscopy modeling results are discussed in this paper, focusing on the n = 4 to n = 2 line transitions of Be- and Li-like Kr ions. Collisional radiative atomic kinetic and Stark-broadened spectral line shape calculations show electron temperature Te and density ne sensitivity in the spectrum. The combination of the Te dependence due to the relative intensity of Be-like to Li-like line
-
Intermittent discharge in a complex stripe pattern in dielectric barrier discharge Phys. Plasmas (IF 2.2) Pub Date : 2024-03-15 Yaohua Li, Yue Wang, Yuyang Pan, Miao Tian, Jianhua Zhang, Lifang Dong
The intermittent discharge that filament only discharges once in a cycle rather than once every half-cycle is observed in all the three substructures of the (bright spots)–(dark spots)-halo stripe pattern (BDHSP) in dielectric barrier discharge. The discharge characteristics are investigated by a high-speed video camera, an intensified charge-coupled device camera, and two photomultiplier tubes. It
-
Performance improvement studies of axially partitioned dual band magnetically insulated line oscillator Phys. Plasmas (IF 2.2) Pub Date : 2024-03-15 Sivavenkateswara Rao V.
In magnetically insulated line oscillator (MILO)s, a proportion of device current is responsible for the self-generated magnetic field that aids electron flow confinement in the anode cathode gap, thereby suitable RF generation. The device currents should not be high due to its direct impact on device efficiency, and electron energy depositions at load can lead to anode plasma formation. Also, the
-
Dispersion and damping of magnetohydrodynamic modes in radiative plasmas Phys. Plasmas (IF 2.2) Pub Date : 2024-03-14 Safeer Sadiq, Shahzad Mahmood
The presented work introduces a theoretical model for radiative magnetohydrodynamics (RMHD) in the equilibrium diffusion limit, focusing on the dynamics of radiation energy. For small amplitude waves, the basic set of dynamic equations is perturbed to derive the dispersion relation for three fundamental modes: fast, intermediate, and slow magnetosonic waves in RMHD plasmas. The study reveals that both
-
Phase-space evolution of quasiparticle excitations in electron gas Phys. Plasmas (IF 2.2) Pub Date : 2024-03-14 M. Akbari-Moghanjoughi
In this research, we use the dual lengthscale quasiparticle model for collective quantum excitations in electron gas to study the time evolution of the Wigner function. The linearized time-dependent Schrödinger–Poisson system for quasiparticles is used to study the dynamics of initial known stationary and damped solutions in an electron gas with arbitrary degree of degeneracy. The self-consistent potential
-
Spatiotemporal theory of a gyrotron based on a three-mirror cavity Phys. Plasmas (IF 2.2) Pub Date : 2024-03-14 E. M. Novak, A. V. Savilov
We present the quasi-analytical spatiotemporal theory of the resonant traveling-wave tube scheme of a gyrotron based on the transverse amplifications of the operating wave and on the use of a remote delayed feedback. The main idea is to implement a system with a dense spectrum of eigenmodes, which makes it possible to smoothly adjust the generation frequency by switching from mode to mode when the
-
The ion cyclotron parametric instabilities and the anomalous heating of ions in the scrape-off layer of tokamak plasma in the high harmonic fast wave heating regime Phys. Plasmas (IF 2.2) Pub Date : 2024-03-14 V. V. Mikhailenko, Hae June Lee, V. S. Mikhailenko
The electrostatic parametric instabilities of a plasma, driven by the high harmonic fast wave (HHFW) with frequency at ion cyclotron (IC) harmonics of order 30–50 are investigated numerically. The derived numerical results are consistent with parametric decay of HHFW into the high harmonic IC (Bernstein) wave and an unobserved IC quasimode under conditions of the negligible small electron Landau damping
-
Harmonic generation and modulation based on intense x-ray interaction with crystal-like structures Phys. Plasmas (IF 2.2) Pub Date : 2024-03-14 Weikang Cai, Lingang Zhang, Xuesong Geng, Xiaomei Zhang, Baifei Shen, Liangliang Ji
The rapid advancement of x-ray free-electron laser technology facilitates the attainment of relativistic attosecond x-ray laser pulses in the future. It could serve as an ideal source to explore x-ray-driven high-energy density physics, such as particle acceleration and secondary radiation at solid densities. Here, utilizing particle-in-cell simulations, we systematically investigate high-order harmonic
-
Evaluation of methods to counteract multipactor phenomena in X-band waveguides Phys. Plasmas (IF 2.2) Pub Date : 2024-03-13 H. Spencer, D. Wright, A. Gregory, J. Mankowski, J. Stephens, J. Dickens, A. Neuber
This study investigates multipactor mitigation techniques in X-band geometries, focusing on surface modifications, surface conditioning, and additive manufacturing. Surface modifications include geometric alterations such as dimpled surfaces. Experimental results demonstrate that 3D-printed copper test pieces can achieve a multipactor onset threshold comparable to traditionally machined test pieces
-
3D cylindrical BGK model of electron phase-space holes with finite velocity and polarization drift Phys. Plasmas (IF 2.2) Pub Date : 2024-03-12 Gaëtan Gauthier, Thomas Chust, Olivier Le Contel, Philippe Savoini
Nonlinear kinetic structures, called electron phase-space holes (EHs), are regularly observed in space and experimental magnetized plasmas. The existence of EHs is conditioned and varies according to the ambient magnetic field and the parameters of the electron beam(s) that may generate them. The objective of this paper is to extend the 3D Bernstein–Greene–Kruskal model with cylindrical geometry developed
-
Laser-driven quasi-static B-fields for magnetized high-energy-density experiments Phys. Plasmas (IF 2.2) Pub Date : 2024-03-07 C. Vlachos, V. Ospina-Bohórquez, P. W. Bradford, G. Pérez-Callejo, M. Ehret, P. Guillon, M. Lendrin, X. Vaisseau, B. Albertazzi, E. Soussan, M. Koenig, S. Malko, C. Kaur, M. Gjevre, R. Fedosejevs, M. Bailly-Grandvaux, C. A. Walsh, R. Florido, F. Suzuki-Vidal, C. McGuffey, J. Saret, F. N. Beg, T. Chodukowski, T. Pisarczyk, Z. Rusiniak, J. Dostal, R. Dudzak, A. Calisti, S. Ferri, L. Volpe, N. C. Woolsey
We present measurements of magnetic fields generated in laser-driven coil targets irradiated by laser pulses of nanosecond duration, 1.053 μm wavelength, 500 J energy, and ∼1015 W/cm2 intensity, at the LULI2000 facility. Using two perpendicular probing axes, proton deflectometry is used to characterize the coil current and static charge at different times. Results reveal various deflection features
-
Linear gyrokinetic theory of two-dimensional ion-temperature-gradient mode in tokamaks Phys. Plasmas (IF 2.2) Pub Date : 2024-03-07 Yuefeng Qiu, Jie Wang, Shaojie Wang
The investigation of the two-dimensional (2D) linear ion-temperature-gradient (ITG) mode in toroidal plasma is carried out in ballooning mode representation. A novel approach to solve the radial envelope structure is proposed by constructing radial differential eigenequation. The important lemma (∂ω/∂θk)|θk=0=0 is proved and employed to construct a numerically solvable eigenequation. We have developed
-
Electromagnetic emission from plasma with counter-streaming electron beams in the regime of oblique instability dominance Phys. Plasmas (IF 2.2) Pub Date : 2024-03-07 V. V. Annenkov, E. P. Volchok, I. V. Timofeev
In this study, we investigate the generation of electromagnetic emission near the second harmonic of the plasma frequency induced by pairs of counter-propagating electron beams. Such systems can naturally occur in cosmic plasmas when particle acceleration regions are closely spaced, and they can also be implemented in a laboratory device. We specifically focus on the regime where the oblique beam–plasma
-
Nonlinear periodic ion-acoustic waves in nonthermal plasmas Phys. Plasmas (IF 2.2) Pub Date : 2024-03-07 Frank Verheest, Carel P. Olivier
A Sagdeev pseudopotential analysis is developed for the propagation of nonlinear periodic ion-acoustic waves in a plasma comprising cold fluid ions and various models of nonthermal electron descriptions. In plasma nonlinear wave studies, whether addressing solitary or periodic modes, the more common nonthermal distributions are the Cairns, kappa, and Tsallis models. A mathematically and physically
-
Collimated hot electron generation from sub-wavelength grating target irradiated by a femtosecond laser pulse of relativistic intensity Phys. Plasmas (IF 2.2) Pub Date : 2024-03-07 Kamalesh Jana, Amit D. Lad, Guo-Bo Zhang, Bo-Yuan Li, V. Rakesh Kumar, Moniruzzaman Shaikh, Yash M. Ved, Min Chen, G. Ravindra Kumar
We investigate the production of hot electrons from the interaction of relativistically intense (I>1018 W/cm2) ultrashort (25 fs) laser pulses with sub-wavelength grating target. We measure the hot electron angular distribution and energy spectra for grating target and compare them with those from a planar mirror target. We observe that hot electrons are emitted in a collimated beam along the specular
-
Radiation and heat transport in divergent shock–bubble interactions Phys. Plasmas (IF 2.2) Pub Date : 2024-03-06 K. Kurzer-Ogul, B. M. Haines, D. S. Montgomery, S. Pandolfi, J. P. Sauppe, A. F. T. Leong, D. Hodge, P. M. Kozlowski, S. Marchesini, E. Cunningham, E. Galtier, D. Khaghani, H. J. Lee, B. Nagler, R. L. Sandberg, A. E. Gleason, H. Aluie, J. K. Shang
Shock–bubble interactions (SBIs) are important across a wide range of physical systems. In inertial confinement fusion, interactions between laser-driven shocks and micro-voids in both ablators and foam targets generate instabilities that are a major obstacle in achieving ignition. Experiments imaging the collapse of such voids at high energy densities (HED) are constrained by spatial and temporal
-
Coupling dynamics of capsule interior defects and its impact on hydrodynamic instabilities at ablation fronts for inertial confinement fusion implosions Phys. Plasmas (IF 2.2) Pub Date : 2024-03-06 Y. X. Liu, L. F. Wang, Z. Chen, Z. Y. Li, J. F. Wu, J. Q. Dong, S. Y. Zou, Z. Yan, J. Li, Z. Lei, W. H. Ye, Y. J. Li
The micrometer-scale internal defect in the capsule is one of the most important factors that limit implosion performance in inertial confinement fusion (ICF) experiments, which creates instability seeds as shocks propagate through the capsule shell. Here, we report the generation mechanism of vortex pairs resulting from the interaction of shock waves with multiple bubbles, as well as the origin of
-
Criterion for long sustained highly peaked ion temperature in diverted configuration of KSTAR tokamak Phys. Plasmas (IF 2.2) Pub Date : 2024-03-06 H. Han, J. Chung, Y. M. Jeon, J. Kang, Y. S. Na, W. H. Ko, J. W. Juhn, J. Jeong, H. S. Kim, J. Jang, S. H. Hahn, J. K. Lee, Y. H. Lee, S. J. Park, W. C. Kim, S. W. Yoon
In the context of KSTAR plasma research, the discovery of the fast ion regulated enhanced mode is noteworthy due to its remarkable ability to maintain ion temperatures exceeding up to 10 keV for a few tens of seconds, avoid impurity accumulation, and keep low loop voltages. This new plasma operating scenario is achieved in a diverted configuration plasma by avoiding the H-mode transitions with sufficient
-
Neoclassical transport of tungsten ion bundles in total-f neoclassical gyrokinetic simulations of a whole-volume JET-like plasma Phys. Plasmas (IF 2.2) Pub Date : 2024-03-06 J. Dominski, C. S. Chang, R. Hager, S. Ku, E. S. Yoon, V. Parail
The application of a bundling technique to model the diverse charge states of tungsten impurity species in total-f gyrokinetic simulations is demonstrated. The gyrokinetic bundling method strategically groups tungsten ions of similar charge, optimizing computational efficiency. The initial radial configuration of these bundles and their respective charges are derived from a coronal approximation and
-
Low-frequency whistler waves driven by energetic electrons in plasmas of solely electron cyclotron wave heating Phys. Plasmas (IF 2.2) Pub Date : 2024-03-06 Mingyuan Wang, Yuejiang Shi, Jiaqi Dong, Xinliang Gao, Quanming Lu, Ziqi Wang, Wei Chen, Adi Liu, Ge Zhuang, Yumin Wang, Shikui Cheng, Mingsheng Tan, Songjian Li, Shaodong Song, Tiantian Sun, Bing Liu, Xianli Huang, Yingying Li, Xianming Song, Baoshan Yuan, Y.-K. Martin Peng
Whistler waves are a type of low-frequency electromagnetic wave common in nature, which is usually associated with energetic electron phenomena. This study presents experimental observations of low-frequency whistler wave instabilities driven by energetic electrons through wave–particle interactions on EXL-50. The energetic electrons are generated by electron cyclotron waves (ECWs) through stochastic
-
Modification of the resistive tearing instability with Joule heating by shear flow Phys. Plasmas (IF 2.2) Pub Date : 2024-03-06 J. De Jonghe, R. Keppens
We investigate the influence of background shear flow on linear resistive tearing instabilities with Joule heating for two compressible plasma slab configurations: a Harris current sheet and a force-free, shearing magnetic field that varies its direction periodically throughout the slab, possibly resulting in multiple magnetic nullplanes. To do so, we exploit the latest version of the open-source,
-
Trapping and actively transporting single particles of arbitrary properties in low-pressure rf plasmas with and without a magnetic field Phys. Plasmas (IF 2.2) Pub Date : 2024-03-06 Pubuduni Ekanayaka, Chuji Wang, Saikat Chakraborty Thakur, Edward Thomas
We report the experimental realization of optical trapping and controlled manipulations of single particles of arbitrary properties, e.g., nano- to micrometer in size, transparent spheres to strongly light absorbing nonspherical particles, in low-pressure rf plasmas. First, we show optical trapping and transport of single particles in an unmagnetized rf plasma. Then, we show similar observations in
-
Synthesizing impurity clustering in the edge plasma of tokamaks using neural networks Phys. Plasmas (IF 2.2) Pub Date : 2024-03-06 Zetao Lin, Thibault Maurel-Oujia, Benjamin Kadoch, Philipp Krah, Nathaniel Saura, Sadruddin Benkadda, Kai Schneider
This work investigates the behavior of impurities in edge plasma of tokamaks using high-resolution numerical simulations based on Hasegawa–Wakatani equations. Specifically, it focuses on the behavior of inertial particles, which has not been extensively studied in the field of plasma physics. Our simulations utilize one-way coupling of a large number of inertial point particles, which model plasma
-
MHD stability of spherical tokamak equilibria with non-monotonic q-profiles Phys. Plasmas (IF 2.2) Pub Date : 2024-03-05 S. C. Jardin, S. Munaretto, N. M. Ferraro, S. M. Kaye, A. Kleiner, B. C. Lyons
We use the 3D magnetohydrodynamic (MHD) code M3D-C1 [Jardin et al., Comput. Sci. Discovery 5, 014002 (2012)] to examine the MHD stability and subsequent evolution of NSTX shot 129169. This discharge had a period with a non-monotonic safety factor profile, q (reversed shear), which was terminated by a MHD event that abruptly lowered the central safety factor, q0, and greatly reduced the peakedness of
-
Loss cone effects and monotonic sheath conditions of a partially magnetized plasma sheath Phys. Plasmas (IF 2.2) Pub Date : 2024-03-05 Andres M. Castillo, Kentaro Hara
In this Letter, we propose the conditions for monotonic plasma sheaths adjacent to a floating wall in the presence of an applied, oblique magnetic field. The electron velocity distribution function (VDF) at the sheath edge obtained from a kinetic model exhibits a loss cone shaped truncation. Using an approximation of the truncated VDF, we derive an analytical framework of the sheath edge condition
-
Quasi-monoenergetic heavy ion acceleration driven by sub-100 PW linearly polarized laser pulses in the radiation-dominated QED regime Phys. Plasmas (IF 2.2) Pub Date : 2024-03-05 Na Zhao, Longfei Gan, Ke Liu, Debin Zou, Yuan Zhou, Guobo Zhang, Weiquan Wang, Hongbin Zhuo
Heavy ion acceleration from an ultrathin foil target irradiated by a p-polarized and spatially Gaussian laser pulse at intensity of 1023 W/cm2 is studied by using two-dimensional particle-in-cell simulations. We find that, in the extremely intense laser fields, the radiation reaction force from bright γ-rays radiated by radially oscillating electrons is large enough to match the Coulomb explosive force
-
SPH code development for X-pinch plasma simulation Phys. Plasmas (IF 2.2) Pub Date : 2024-03-05 Su-San Park, Deok-Kyu Kim, Seunggi Ham, Kyoung-Jae Chung, Yong-Su Na, Eung Soo Kim
We have developed the first smoothed particle hydrodynamics code for investigating X-pinch plasmas driven by pulsed power generators. To achieve the required code performance, we incorporated and discussed appropriate physics models capable of simulating the X-pinch phenomenon across various domains, encompassing equation of state, plasma transport, and radiation effects. The simulations were conducted
-
Coupled nonlinear drift and IAWs in streaming O–H plasma of upper ionosphere Phys. Plasmas (IF 2.2) Pub Date : 2024-03-05 Shaukat Ali Shan, Usman Saeed, Hamid Saleem
Nonlinear structures formed by the coupled drift wave (DW) and ion acoustic waves (IAWs) are studied in a magnetized inhomogeneous collisionless bi-ion plasma with ions shear flow along the ambient magnetic field B=B0ẑ. The electrons are assumed to follow double spectral index (r, q) distribution in which r shows the flat top nature, while q is responsible for the shape of the distribution at the
-
A direct Monte Carlo approach for the modeling of neutrals at the plasma edge and its self-consistent coupling with the 2D fluid plasma edge turbulence model HESEL Phys. Plasmas (IF 2.2) Pub Date : 2024-03-05 Kristoffer Kvist, Alexander Simon Thrysøe, Troels Haugbølle, Anders Henry Nielsen
This paper presents a novel coupling of a kinetic description of neutrals with a fluid description of a fusion plasma. The code, plasma interacting super-atoms and molecules (PISAM), employs a grid-free Cartesian geometry and a direct simulation Monte Carlo approach to solve the kinetic equations of deuterium atoms and molecules. The grid-free geometry and the parallel nature of the neutral dynamics
-
Study of radiative shocks using 2D interferometry and XUV spectroscopy Phys. Plasmas (IF 2.2) Pub Date : 2024-03-05 R. L. Singh, C. Stehlé, M. Kozlova, M. Cotelo, J. Dostal, R. Dudzák, R. Rodriguez, P. Velarde, P. Barroso, F. Suzuki-Vidal, T. Pisarczyk
We report new experimental results on radiative shocks obtained in Xenon and Argon in gas cells at two different pressures below 1 bar. These shock waves are generated by the interaction of the PALS iodine laser on a CH–Au foil with a typical velocity in the range of 50–100 km/s depending on the variable laser intensity, pressure, and gas. Attention is paid to the morphology and the dynamics of the
-
Alfvénic fluctuations in the expanding solar wind: Formation and radial evolution of spherical polarization Phys. Plasmas (IF 2.2) Pub Date : 2024-03-05 L. Matteini, A. Tenerani, S. Landi, A. Verdini, M. Velli, P. Hellinger, L. Franci, T. S. Horbury, E. Papini, J. E. Stawarz
We investigate properties of large-scale solar wind Alfvénic fluctuations and their evolution during radial expansion. We assume a strictly radial background magnetic field B∥R, and we use two-dimensional hybrid (fluid electrons, kinetic ions) simulations of balanced Alfvénic turbulence in the plane orthogonal to B; the simulated plasma evolves in a system comoving with the solar wind (i.e., in the
-
Kinetic closures for unmagnetized and magnetized plasmas Phys. Plasmas (IF 2.2) Pub Date : 2024-03-04 Kyoung-Chan Park, Jeong-Young Ji, Yoonji Lee, Yong-Su Na
Parallel and perpendicular closures with cyclotron resonance effects retained for the five-moment (density, temperature, and flow velocity) fluid equations are derived by solving the kinetic equation with the Bhatnagar–Gross–Krook operator in Fourier space. For parallel propagation, the parallel closures are reduced to those of Ji et al. [Phys. Plasmas 20, 082121 (2013)]. The closures when combined
-
Probabilistic locked mode predictor in the presence of a resistive wall and finite island saturation in tokamaks Phys. Plasmas (IF 2.2) Pub Date : 2024-03-04 C. Akçay, John M. Finn, Dylan P. Brennan, K. E. J. Olofsson, A. J. Cole
We present a framework for estimating the probability of locking to an error field in a rotating tokamak plasma. This leverages machine learning methods trained on data from a mode-locking model, including an error field, resistive magnetohydrodynamics modeling of the plasma, a resistive wall, and an external vacuum region, leading to a fifth-order ordinary differential equation (ODE) system. It is
-
Shock formation in flowing plasmas by temporally and spatially smoothed laser beams Phys. Plasmas (IF 2.2) Pub Date : 2024-03-04 J. D. Ludwig, S. Hüller, H. A. Rose, C. Bruulsema, W. Farmer, P. Michel, A. L. Milder, G. F. Swadling, W. Rozmus
The cumulative impact of multiple laser speckles on a supersonic plasma flow across optically smoothed laser beams is investigated. The bending of laser beams caused by ponderomotive laser–plasma coupling, together with flow, leads to plasma a momentum-conserving response that results in a deceleration of the flow. Once the flow velocity decreases to a subsonic level, the action of the laser beams
-
Collisional space-charge-limited current with monoenergetic velocity: From Child–Langmuir to Mott–Gurney Phys. Plasmas (IF 2.2) Pub Date : 2024-03-04 Lorin I. Breen, Allen L. Garner
All theories coupling electron emission theories ultimately approach the space-charge-limited current (SCLC) in vacuum, given by the Child–Langmuir (CL) law, for sufficiently high voltage, or the Mott–Gurney (MG) law for finite electron mobility and high (but not infinite) voltage. These analyses demonstrate the presence of an SCLC regime that cannot be described by either CL or MG. Here, we derive
-
Measurement of a force imparted to a magnetic nozzle by electron diamagnetism Phys. Plasmas (IF 2.2) Pub Date : 2024-03-04 Soya Sumikawa, Kazunori Takahashi
An electron-beam plasma source consisting of a hot filament is installed near the throat of the magnetic nozzle immersed in a vacuum chamber. The low plasma potential of about 5 V is formed over the region of the measurement in the weakly ionized and partially magnetized argon plasma expanding along a magnetic nozzle; an electric field is much smaller than a pressure gradient, providing a force balance
-
0.22-THz extended interaction klystron based on orthogonal interconnection structure Phys. Plasmas (IF 2.2) Pub Date : 2024-03-04 Zhenhua Wu, Ruizhe Ren, Jielong Li, Zongjun Shi, Lei Ni, Xiaoxing Chen, Min Hu, Renbin Zhong, Kaichun Zhang, Diwei Liu, Wei Wang, Tao Song, Shenggang Liu
This paper presents an extended interaction klystron (EIK) operating at 0.22 THz based on a four-sheet-beam orthogonal interconnection structure (OIS). The proposed OIS comprises four vertically positioned trapezoidal line structures, significantly enhancing the coupling efficiency between cavities and achieving optimal interactions with the TM81 mode. This study investigates the dispersion characteristics
-
Simultaneous reproduction of experimental profiles, fluxes, transport coefficients, and turbulence characteristics via nonlinear gyrokinetic profile predictions in a DIII-D ITER similar shape plasma Phys. Plasmas (IF 2.2) Pub Date : 2024-03-01 N. T. Howard, P. Rodriguez-Fernandez, C. Holland, T. Odstrcil, B. Grierson, F. Sciortino, G. McKee, Z. Yan, G. Wang, T. L. Rhodes, A. E. White, J. Candy, C. Chrystal
Experimental conditions obtained on the DIII-D tokamak in the ITER Similar Shape (ISS) have been compared extensively with nonlinear gyrokinetic simulation using the CGYRO code [Candy et al., J. Comput. Phys. 324, 73–93 (2016)] with comparisons spanning ion and electron heat fluxes, electron and impurity particle transport, and turbulent fluctuation levels and characteristics. Bayesian optimization
-
A review of the impact of ground test-related facility effects on gridded ion thruster operation and performance Phys. Plasmas (IF 2.2) Pub Date : 2024-03-01 John E. Foster, Tyler J. Topham
A key consideration in the interpretation of ground test data of electric propulsion devices purposed for spaceflight is understanding how facility-effects influence thruster operation. This understanding is critical to the prediction of actual thruster performance in space. The necessity of science-based predictions gleaned from ground tests are particularly critical at higher thruster power levels
-
Terahertz super-radiance from picosecond electron bunches moving through a micro-undulator Phys. Plasmas (IF 2.2) Pub Date : 2024-03-01 N. S. Ginzburg, M. N. Vilkov, A. M. Malkin, A. S. Sergeev, I. V. Bandurkin, A. E. Fedotov, N. Yu. Peskov, P. V. Loginov
We suggest using emission from the photoinjector-formed electron bunches moving through micro-undulators for generation of powerful super-radiant pulses in the terahertz/far infrared frequency range. Within the time-domain quasi-optical approach, we demonstrate the spatial coherence of emission with narrow angular spectrum from the electron bunches with transverse size limited by the Fresnel parameter
-
A validation study of a bounce-averaged kinetic electron model in a KSTAR L-mode plasma Phys. Plasmas (IF 2.2) Pub Date : 2024-02-29 Sumin Yi, C. Sung, E. S. Yoon, Jae-Min Kwon, T. S. Hahm, D. Kim, J. Kang, Janghoon Seo, Y. W. Cho, Lei Qi
We extend the bounce-averaged kinetic (BK) electron model to be applicable in general tokamak magnetic geometries and implement it on the global δf particle-in-cell gyrokinetic code gKPSP. We perform a benchmark study of the updated BK model against the gyrokinetic electron model in flux-tube codes, CGYRO and GENE. From the comparisons among the simulations based on the local parameters of a KSTAR
-
Coupled models for propagation of explosive shock waves in cylindrical and spherical geometries Phys. Plasmas (IF 2.2) Pub Date : 2024-02-29 C. Y. Cao, Y. B. Sun, C. Wang, X. Y. Jia, R. H. Zeng, T. H. Yang
The propagation of shock waves in different geometries is crucial in engineering and scientific applications. A comprehensive model is developed to elucidate the hydrodynamic growth and decay of shock waves in cylindrical and spherical geometries by using the strong shock wave assumption. This model takes into consideration the conservation equations governing mass, momentum, and energy, thereby allowing
-
Sensitivity analysis of multipactor susceptibility zone to variations in secondary electron yield values Phys. Plasmas (IF 2.2) Pub Date : 2024-02-29 M. Mirmozafari, N. Behdad, J. H. Booske
We present a sensitivity analysis of the multipactor susceptibility zones to variations in the secondary electron yield (SEY) of materials, specifically focusing on the first and second unity crossover points of SEYs. In conducting this research, we leveraged our semi-analytic approach, which allows for the rapid prediction of the full multipactor zones with enhanced accuracy. Using this approach,
-
Super-heavy ion beams generated by a multi-PW femtosecond laser Phys. Plasmas (IF 2.2) Pub Date : 2024-02-29 J. Domański, J. Badziak
The numerical investigations into the acceleration of superheavy ions driven by a multi-PW, 30 fs laser pulse with a peak intensity from 5 × 1022 to 2 × 1023 W/cm2 were carried out using an advanced 2D3V particle-in-cell code. The properties of laser-accelerated Au, Pb, Bi, and U ion beams, such as ionization and ion energy spectra, ion beam energies, angular distributions of the beam fluence, the
-
Efficient muon acceleration in laser wakefields driven by single or combined laser pulses Phys. Plasmas (IF 2.2) Pub Date : 2024-02-28 Pan-Fei Geng, Min Chen, Zheng-Ming Sheng
Laser plasma wakefields can provide extremely high fields both in transverse and longitudinal directions, which are very suitable for short-lived charged particle acceleration, such as muons. To get efficient capture and acceleration, we have numerically investigated the acceleration of externally injected muons in laser wakefields driven by usual Gaussian or flying focus lasers. The muons are produced
-
Impact of triangularity on edge peeling–ballooning modes in H-mode plasmas Phys. Plasmas (IF 2.2) Pub Date : 2024-02-28 Y. Zhang, Z. B. Guo, C. C. Qin, X. Q. Xu, Z. Y. Li, M. Xu
Triangularity is an important shaping parameter in tokamak plasmas that affects the edge plasma state. In this work, we utilize the BOUT++ code to study the effect of positive and negative triangularity on the peeling–ballooning modes with H-mode profiles. The model equilibria with a JET-like geometry are self-consistently generated by the CORSICA equilibrium code, with a fixed pressure profile when
-
From KMS Fusion to HB11 Energy and Xcimer Energy, a personal 50 year IFE perspective Phys. Plasmas (IF 2.2) Pub Date : 2024-02-28 Thomas A. Mehlhorn
Shortly after the laser was invented in 1960, scientists sought to use it for thermonuclear fusion. By 1963, Livermore had a classified laser inertial confinement fusion (ICF) program and leaders predicted scientific breakeven by 1973. In 1974, KMS Fusion, Inc. announced thermonuclear neutrons from a laser target and promised grid electricity within 10 years. Private capital was attracted, but the
-
Specialized design for three basic mask patterns counteract charging effects during plasma etching Phys. Plasmas (IF 2.2) Pub Date : 2024-02-27 Peng Zhang
In the plasma etching technique, effectively suppressing charging effects is crucial for achieving a high-quality transfer of the mask pattern onto the substrate. For instance, mask patterns that combine complex shapes frequently exhibit a noticeable “corner effect,” characterized by significant variations in physical quantities at locations where curvature changes rapidly. This study investigates
-
Impact of flow-induced beam deflection on beam propagation in ignition scale hohlraums Phys. Plasmas (IF 2.2) Pub Date : 2024-02-27 W. A. Farmer, C. Ruyer, J. A. Harte, D. E. Hinkel, D. S. Bailey, E. Kur, O. L. Landen, N. Lemos, P. A. Michel, J. D. Moody, D. J. Strozzi, C. R. Weber, G. B. Zimmerman
Experiments examining the amount of specular reflection (or “glint”) within hohlraums containing different gas fill densities have recently been performed. Simulations of these experiments are presented that show using a single flux limiter cannot explain the decrease in glinted power with increasing gas fill density. The hypothesis that flow-induced beam deflection alters laser absorption is presented
-
Tracking dynamo mechanisms from local energy transfers: Application to the von Kármán sodium dynamo Phys. Plasmas (IF 2.2) Pub Date : 2024-02-26 M. Creff, H. Faller, B. Dubrulle, J.-L. Guermond, C. Nore
Motivated by the observation that dynamo is a conversion mechanism between kinetic and magnetic energy, we develop a new approach to unravel dynamo mechanism based on local (in space, scale, and time) energy budget describing dissipation and scale-by-scale energy transfers. Our approach is based upon a new filtering approach that can be used effectively for any type of meshes, including unstructured
-
Radiation-driven diffusive transport of fast electrons in solar flares Phys. Plasmas (IF 2.2) Pub Date : 2024-02-23 R. Duclous, V. Tikhonchuk, L. Gremillet, B. Martinez, T. Leroy, P.-E. Masson Laborde, J.-C. Pain, A. Decoster
Fast electron scattering on plasma ions due to stimulated Bremsstrahlung is investigated and modeled. Comparison with Coulomb scattering suggests that stimulated Bremsstrahlung scattering can be dominant in low-density, radiation-driven plasmas, provided that the radiation spectrum has a sufficiently high brightness temperature in the neighborhood of the plasma frequency. While stimulated Bremsstrahlung
-
Observation of non-planar dust acoustic solitary wave in a strongly coupled dusty plasma Phys. Plasmas (IF 2.2) Pub Date : 2024-02-23 Prarthana Gogoi, Bidyut Chutia, Paragjyoti Sut, Yoshiko Bailung, Nirab C. Adhikary, H. Bailung
The nonlinear evolution and propagation of a stable dust acoustic solitary wave (DASW) in a non-planar geometry is investigated here. The experiment is performed in a strongly coupled dusty plasma consisting of monodisperse micrometer sized particles levitated in the sheath of a capacitively coupled radio frequency argon plasma. The non-planar waves are generated with the help of a cylindrical conducting
-
Electronic excitation of high-order spoof surface plasmons on metallic grating at terahertz frequencies Phys. Plasmas (IF 2.2) Pub Date : 2024-02-23 Yong-Qiang Liu, Yan Wang, Jinhai Sun, Yong Zhu, Hongcheng Yin
High-order spoof surface plasmon (SSP) mode on corrugated metallic surfaces can find many interesting applications, such as in imaging, sensing, transmission and enhanced radiation source, etc. In this paper, an efficient excitation method of the high-order SSP mode by using an injected electron beam on the uniform rectangular metallic grating is proposed and investigated numerically. Based on the
-
Comprehensive study of magnetic field evolution in relativistic jets based on 2D simulations Phys. Plasmas (IF 2.2) Pub Date : 2024-02-23 Amin Esmaeili, Yutaka Fujita
We use two-dimensional particle-in-cell simulations to investigate the generation and evolution of the magnetic field associated with the propagation of a jet for various initial conditions. We demonstrate that, in general, the magnetic field is initially grown by the Weibel and Mushroom instabilities. However, the field is saturated by the Alfvén current limit. For initially non-magnetized plasma
-
Electron energy gain due to a laser frequency modulation experienced by electron during betatron motion Phys. Plasmas (IF 2.2) Pub Date : 2024-02-23 A. Arefiev, I.-L. Yeh, K. Tangtartharakul, L. Willingale
Direct laser acceleration of electrons is an important energy deposition mechanism for laser-irradiated plasmas that is particularly effective at relativistic laser intensities in the presence of quasi-static laser-driven plasma electric and magnetic fields. These radial electric and azimuthal magnetic fields provide transverse electron confinement by inducing betatron oscillations of forward-moving
-
Ionization and neutral gas heating efficiency in radio frequency electrothermal microthrusters: The role of driving frequency Phys. Plasmas (IF 2.2) Pub Date : 2024-02-23 Sid Leigh, Scott J. Doyle, Gregory J. Smith, Andrew R. Gibson, Rod W. Boswell, Christine Charles, James P. Dedrick
The development of compact, low power, charge–neutral propulsion sources is of significant recent interest due to the rising application of micro-scale satellite platforms. Among such sources, radio frequency (rf) electrothermal microthrusters present an attractive option due to their scalability, reliability, and tunable control of power coupling to the propellant. For micropropulsion applications
-
Excitation of cylindrical and spherical precursor solitons in a flowing dusty plasma: Experimental and simulation studies Phys. Plasmas (IF 2.2) Pub Date : 2024-02-22 Krishan Kumar, P. Bandyopadhyay, Swarnima Singh, A. Sen
We report the first laboratory observation of precursor cylindrical and spherical solitons excited in a flowing dusty plasma. The experiments are carried out in an inverted Π-shaped dusty plasma experimental device in which a dust cloud is created in a background Argon plasma using micrometer-sized Kaolin particles. Using the single gas injection technique, the dust fluid is made to flow in a controlled
-
High-frequency dissipative MHD waves in straight magnetic cylindrical plasma: Coronal loops heating application Phys. Plasmas (IF 2.2) Pub Date : 2024-02-22 Ankit Kumar, V. S. Pandey
The theoretical model for analyzing the waves and oscillatory behavior in the structured solar corona using straight magnetic cylindrical geometry filled with uniform low-β plasma has been recognized as the most preferable classical model for the last few decades. A number of observations, since the first observation of the transition region and coronal explorer to the latest ones, have been adequately
-
Preliminary study of dual annular multiple-beam cathode for V-band coaxial transit-time oscillator Phys. Plasmas (IF 2.2) Pub Date : 2024-02-21 Fanbo Zeng, Jiande Zhang, Juntao He, Junpu Ling
Since the research toward high-power millimeter-wave generator becomes a tendency in high-power microwave, overmoded structure with the high-order mode has been a considerable interest because of its potential to increase power handling capacity (PHC). To expand the PHC of V-band transit-time oscillator and excite higher mode TM03, a dual annular multiple-beam cathode has been proposed. In the geometric
-
Unveiling non-flat profiles within magnetic islands in tokamaks Phys. Plasmas (IF 2.2) Pub Date : 2024-02-21 Wonjun Tae, E. S. Yoon, Min Sup Hur, G. J. Choi, J. M. Kwon, M. J. Choi
The presence of non-flat profiles on magnetic island is studied for the first time through gyrokinetic simulations alongside a simplified Lagrangian model. We have identified that inside a magnetic island, the non-flatness of density and temperature profiles is controlled by a dimensionless parameter α≡w*ŝϵ/qρ*, which is a function of normalized island width w*=w/a0, magnetic shear ŝ, inverse aspect