Browsing by Author "Carril Pardo, Hugo Alexis"

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    Estudio del Régimen Lineal y No-lineal en un Plasma Electron-Ion No-magnetizado.
    (Universidad de Concepción, 2020) Carril Pardo, Hugo Alexis; Araneda Sepúlveda, Jaime Andrés
    Para estudiar cómo se modifica la dinámica de un plasma Maxwelliano de electrones no magnetizado con la presencia de iones positivos pesados, el presente trabajo tiene por objetivo estudiar los regímenes amortiguado y no lineal de perturbaciones en un plasma Maxwelliano electrón-ión sin deriva relativa, considerando una razón de masa mi/me = 1836.153 y razón de carga qi/|qe| = 1.0, específicamente en el rango de bajas frecuencias (ωr ≤ 0.2ωpe) y velocidades del orden de la velocidad de fase de ondas-ión acústicas vφ,IA para el número de onda excitado, con la razón de temperatura Ti/Te = 1.0. Todo el estudio se realiza por medio de simulaciones numéricas del sistema de ecuaciones de Vlasov-Poisson usando interpolación espectral en posición y velocidad, e integración simpléctica en la dependencia temporal. En el caso de perturbaciones amortiguadas se espera que las ondas de Langmuir e ión-acústicas se propaguen relativamente independientes una de la otra y las distribuciones de ambas especies exhiban un comportamiento opuesto en el rango de velocidades de interés, mientras que en caso no lineal se espera que surjan ondas electrostáticas solitarias, debido a la presencia de iones móviles, que estén asociadas a solitones ión-acústicos y atrapamiento de electrones.
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    Etudy of the linear and nonlinear regimes in an unmagnetized electron-ion plasma.
    (Universidad de Concepción, 2020) Carril Pardo, Hugo Alexis; Araneda Sepúlveda, Jaime Andrés; Navarro Maldonado, Roberto Elías
    In order to study how the dynamics of an unmagnetized Maxwellian electron plasma is modified by the presence of mobile positive heavy ions, the present work aims to study the regimes of damped and nonlinear perturbations in a driftless Maxwellian electron-ion plasma, considiring a mass ratio mi/me = 1836.153 and charge ratio qi/|qe| = 1.0, specifically in the range of low frequencies (ωr ≤ 0.2ωpe) and velocities in the order of the ion acoustic phase velocity vφ,IA for the excited wavenumber, primarily for the temperature ratio Ti/Te = 1.0. Also, the response of the plasma is studied for different temperature ratios Ti/Te above and below Ti/Te = 1.0. The whole study is accomplished through numerical simulations of the Vlasov-Poisson system of equations using spectral interpolation in position and velocity, and symplectic integration in the time dependency. It is expected that in the case of damped perturbations both Langmuir and ion acoustic waves propagate relatively independent from each other and exhibit opposite behaviors in the velocity range of interest, whereas in the nonlinear case, electrostatic solitary waves are expected to arise due to the presence of heavy mobile ions related to electron trapping and ion acoustic solitons. It is expected that dynamics related to the ions is accentuated with lower ratios Ti/Te.
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    Resonant absorption of the kink mode in a coronal plasma slab via 2D hybrid-PIC simulations: multifluid and kinetic descriptions.
    (Universidad de Concepción, 2026) Carril Pardo, Hugo Alexis; Navarro Maldonado, Roberto Elías; Terradas Calafell, Jaume
    We investigate the resonant absorption kink oscillations in a plasma slab with linearly inhomogeneous particle densities. Different thicknesses of the layers and angles of the background magnetic field to the plane of the slab are studied via 2D−3V PIChybrid simulations. We identify the resonant absorption of the large-scale mode in the inhomogeneous layers and compare its damping rate with a single fluid, linear MHD estimation. Scales in the order of the proton inertial length are achieved in most of the simulated cases, particularly in the case of thinner layers and for moderately magnetized slabs. Quasi-perpendicular fluctuations consistent with Kinetic Alfv´en Waves (KAWs) are generated at the layers only when resonant absorption occurs. The KAWs interact non-linearly and generate a parallel electric field, which subsequently produces density structures and accelerates protons. This causes strong heating and flat-topped distribution. We derive an analytical estimate for this parallel field that reproduces the most relevant signals of the dispersion relations during and after resonant absorption. The transverse particle dynamics are driven by the cross-field drift, causing the transverse temperature to oscillate and grow exponentially due to small-scale fluctuations. Therefore, the proton distribution functions are largely shaped non-resonantly by the KAW activity.
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