Hypervelocity Impacts and Dusty Plasma Lab (HIDPL)https://hdl.handle.net/2104/55172023-12-01T13:29:26Z2023-12-01T13:29:26Z461A machine learning-based Bayesian optimization solution to nonlinear responses in dusty plasmasDing, ZhiyueMatthews, LorinHyde, Truellhttps://hdl.handle.net/2104/117762022-08-16T17:01:40Z2021-06-01T00:00:00Zdc.title: A machine learning-based Bayesian optimization solution to nonlinear responses in dusty plasmas
dc.contributor.author: Ding, Zhiyue; Matthews, Lorin; Hyde, Truell
dc.description.abstract: Nonlinear frequency response analysis is a widely used method for determining system dynamics in the presence of nonlinearities. In dusty plasmas, the plasma–grain interaction (e.g. grain charging fluctuations) can be characterized by a single-particle non-linear response analysis, while grain–grain non-linear interactions can be determined by a multi-particle non-linear response analysis. Here a machine learning-based method to determine the equation of motion in the non-linear response analysis for dust particles in plasmas is presented. Searching the parameter space in a Bayesian manner allows an efficient optimization of the parameters needed to match simulated non-linear response curves to experimentally measured non-linear response curves.
2021-06-01T00:00:00ZDust as probes: Determining confinement and interaction forcesHartmann, PeterRosenberg, MarleneJuhasz, Z.Matthews, LorinSanford, DustinVermillion, KatrinaReyes, JorgeHyde, Truellhttps://hdl.handle.net/2104/117732022-08-16T17:01:47Z2020-10-01T00:00:00Zdc.title: Dust as probes: Determining confinement and interaction forces
dc.contributor.author: Hartmann, Peter; Rosenberg, Marlene; Juhasz, Z.; Matthews, Lorin; Sanford, Dustin; Vermillion, Katrina; Reyes, Jorge; Hyde, Truell
dc.description.abstract: The PK-4 system is a micro-gravity dusty plasma experiment currently in operation on-board
the International Space Station. The experiment utilizes a long DC discharge in neon or argon
gases. We apply our 2D particle-in-cell with Monte Carlo collisions discharge simulation to
compute local plasma parameters that serve as input data for future dust dynamics models.
The simulation includes electrons, Ne+ ions, and Ne^m metastable atoms in neon gas and their
collisions at solid surfaces including secondary electron emission and glass wall charging. On
the time scale of the on-board optical imaging, the positive column appears stable and
homogeneous. On the other hand, our simulations show that on microsecond time scales the
positive column is highly inhomogeneous: ionization waves with phase velocities in the range
between 500 m s−1 and 1200 m s−1 dominate the structure. In these waves, the electric field
and charged particle densities can reach amplitudes up to 10 times of their average value. Our
experiments on ground-based PK-4 replica systems fully support the numerical findings. In the
experiment, the direction of the DC current can be alternated, which has been found to favor
dust particle chain formation. We discuss possible mechanisms for how the highly oscillatory
plasma environment contributes to the dust particle chain formation.
2020-10-01T00:00:00ZIonization waves in the PK-4 direct current neon dischargeAshrafi, KhandakerYousefi, RaziyehChen, MudiMatthews, LorinHyde, Truellhttps://hdl.handle.net/2104/117722022-08-16T17:02:03Z2020-11-01T00:00:00Zdc.title: Ionization waves in the PK-4 direct current neon discharge
dc.contributor.author: Ashrafi, Khandaker; Yousefi, Raziyeh; Chen, Mudi; Matthews, Lorin; Hyde, Truell
dc.description.abstract: Complex plasmas are interesting systems as the charged dust can self-assemble into different types of ordered structures. To understand the mechanisms which govern the transitions from one type of structure to another, it is necessary to know both the dust charge and the confi ning electric fields within the environment, parameters which are difficult to measure independently. As dust is usually confi ned in a plasma sheath where the ions stream from the bulk plasma the negative lower electrode, the problem is further complicated by the ion wake field, which develops downstream of the dust grains in a flowing plasma. The differences in local ion density caused by the wake fi eld change the equilibrium dust charge and shielding distance of the dust grains, and thus affect the interaction between grains. Here we use a molecular dynamics simulation of ion flow past dust grains to investigate the interaction between the dust particles and ions. We consider a long vertical chain of particles confi ned within a glass box placed on the lower electrode of a GEC rf reference cell. We apply the model iteratively to self-consistently determine the dust charge, electric fi eld, and ion density along the length of the chain as well as the ion flow speed. Simulation results indicate that the ion flow speed within the box is subsonic.
2020-11-01T00:00:00ZNonlinear mode coupling and internal resonance observed in a dusty plasmaDing, ZhiyueQiao, KeErnst, N.Kong, JieChen, M.Matthews, L.S.Hyde, T. W.https://hdl.handle.net/2104/109652022-11-09T22:38:18Z2009-10-01T00:00:00Zdc.title: Nonlinear mode coupling and internal resonance observed in a dusty plasma
dc.contributor.author: Ding, Zhiyue; Qiao, Ke; Ernst, N.; Kong, Jie; Chen, M.; Matthews, L.S.; Hyde, T. W.
dc.description.abstract: In this paper, we report the first experimental observation of internal resonance in a dusty plasma,
which shows the intrinsic nonlinearities of dust interactions in plasmas. When driving a system of
vertically aligned dust particle pairs in the vertical direction, the horizontal motion is found to be
excited during onset of internal resonance when the higher-frequency horizontal sloshing mode is
nonlinearly coupled to the vertical breathing mode through the 1:2 commensurable relation. A
theoretical model of the nonlinear interaction of dust particles in plasma is also provided and the
results of the theoretical model are shown to match experimental observations.
2009-10-01T00:00:00ZDust particle pair correlation functions and the non-linear effect of interaction potentialsKong, JieQiao, KeMatthews, L.S.Hyde, T.W.https://hdl.handle.net/2104/109642022-08-16T17:01:49Z2019-07-01T00:00:00Zdc.title: Dust particle pair correlation functions and the non-linear effect of interaction potentials
dc.contributor.author: Kong, Jie; Qiao, Ke; Matthews, L.S.; Hyde, T.W.
dc.description.abstract: Dust temperature is a measure of the energy of the stochastic motion of a dust particle, and is a result of the combination of the Brownian motion and the fluctuations in the dust charge and confining electric field. A method using the equilibrium value of the mean square displacement was recently introduced to obtain the dust temperature experimentally. As a follow up, this paper investigates the relationship between the temperature derived from the mean square displacement technique and a technique using the probability distribution of the displacements obtained from random fluctuations of the dust particle. Experimental results indicate that the harmonic confinement potential acting on the dust particle can be obtained by combining the two methods, allowing the non-linear effect of the confining force to be investigated. The thermal expansion in a one-dimensional vertical chain is discussed as a representative application as it is related to the non-linear confinement force, or the asymmetric confinement potential.
2019-07-01T00:00:00ZComparison of Plasma Magnetic Field Interactions in a Static and Dynamic Plasma FacilityDropmann, MichaelKnapp, A.Eichhorn, C.Loehle, S.Laufer, ReneHerdrich, GeorgMatthews, Lorin Swint.Hyde, Truell Wayne.Fasoulas, StefanosRoeser, Hans-Peterhttps://hdl.handle.net/2104/106452022-08-09T06:36:28Z2016-01-01T00:00:00Zdc.title: Comparison of Plasma Magnetic Field Interactions in a Static and Dynamic Plasma Facility
dc.contributor.author: Dropmann, Michael; Knapp, A.; Eichhorn, C.; Loehle, S.; Laufer, Rene; Herdrich, Georg; Matthews, Lorin Swint.; Hyde, Truell Wayne.; Fasoulas, Stefanos; Roeser, Hans-Peter
dc.description.abstract: Magnetic fields are a principal/widespread/promising tool/instrument in space technology design for the use in advanced propulsion concepts, shielding from radiation or to aid thermal protection during the atmospheric entry of spacecraft. Two experiments have been conducted to investigate the feasibility of using magnetic fields to reduce the heat flux onto a thermal protection system during atmospheric entry. For this purpose a modified heat flux probe with embedded permanent magnets has been exposed to a plasma jet and the structure of the bow shock in front of the probe has been observed using an emission spectroscopy setup. The intensity ratio of ionized argon lines for the experiment with and without magnets has been determined and used to analyze the magnetic field`s impact on the flow. Complementary experiments in a low power capacitively driven plasma have been conducted using micron sized particles as probes to map electric fields in a magnetically perturbed plasma. The results from both experiments are presented and analogies are drawn from both approaches. The experiments have shown that the interactions of the magnetic field with the plasma can create strong electric fields which strongly influence the ions even though the field is too weak to magnetize the ions.
2016-01-01T00:00:00ZDust particle pair correlation functions and the non-linear effect of interaction potentialsKong, JieQiao, KeMatthews, Lorin Swint.Hyde, Truell Wayne.https://hdl.handle.net/2104/106442022-08-09T15:16:01Z2019-07-01T00:00:00Zdc.title: Dust particle pair correlation functions and the non-linear effect of interaction potentials
dc.contributor.author: Kong, Jie; Qiao, Ke; Matthews, Lorin Swint.; Hyde, Truell Wayne.
dc.description.abstract: Dust kinetic temperature is a measure of the energy of the stochastic motion of a dust particle and is a result of the combination of the Brownian motion and the fluctuations in the dust charge and confining electric field. A method using the equilibrium value of the mean square displacement was recently introduced to obtain the dust kinetic temperature experimentally. As a follow up, this paper investigates the relationship between the dust kinetic energy derived from the mean square displacement technique and a technique using the probability distribution of the displacements obtained from random fluctuations of the dust particle. The experimental results indicate that the harmonic confinement potential acting on the dust particle can be obtained by combining the two methods, allowing the nonlinear effect of the confining force to be investigated. The thermal expansion in a 1-D vertical chain is discussed as a representative application as it is related to the nonlinear confinement force, or the asymmetric confinement potential.
2019-07-01T00:00:00ZNonlinear response of vertical paired structure in complex plasmaDing, ZhiyueQiao, KeKong, JieMatthews, Lorin Swint.Hyde, Truell Wayne.https://hdl.handle.net/2104/106432022-08-16T17:02:00Z2019-03-21T00:00:00Zdc.title: Nonlinear response of vertical paired structure in complex plasma
dc.contributor.author: Ding, Zhiyue; Qiao, Ke; Kong, Jie; Matthews, Lorin Swint.; Hyde, Truell Wayne.
dc.description.abstract: The effect of the ion wake downstream of grains immersed in a flowing plasma is observed experimentally through the apparent non-reciprocal grain–grain interactions. Here we extend amplitude-frequency response analysis to examine the nonlinear components of the interaction of a dust particle pair aligned with the ion flow. The particle pair is modeled as two forced coupled oscillators, and a new coordinate system is introduced in which the breathing and sloshing modes are linearly decoupled. Multiple-scale analysis is used to derive analytical expressions for the response in the vertical direction for each mode in this coordinate system. By fitting the analytical expressions to experimentally measured response curves, the nonlinear part of the wake-modified particle–particle interaction is determined and identified as the source for the coupling between the sloshing and breathing modes. It is found that the restoring force acting on the downstream particle is more linear, thus stabilizing the oscillations of the downstream grain.
2019-03-21T00:00:00ZMapping the Plasma Potential in a Glass BoxScott, LoriEllis, NaokiChen, MudiMatthews, Lorin Swint.Hyde, Truell Wayne.https://hdl.handle.net/2104/106422022-08-16T17:01:51Z2019-07-01T00:00:00Zdc.title: Mapping the Plasma Potential in a Glass Box
dc.contributor.author: Scott, Lori; Ellis, Naoki; Chen, Mudi; Matthews, Lorin Swint.; Hyde, Truell Wayne.
dc.description.abstract: Modeling the dynamics of charged dust particles, confined in a glass box placed on the lower electrode of a Gaseous Electronics Conference cell, requires that the interactions between the charged dust, plasma, and boundaries need to be accounted for in a self-consistent manner. The charged lower electrode affects the plasma conditions throughout the glass box, altering the electron and ion densities and temperatures within the plasma sheath. These plasma characteristics determine the charge collected on the walls of the surrounding glass box, the electric potential within the glass box, the dust charge, and ultimately the dynamics of the dust. This paper describes the steps taken to build a simple model of the relationship between the plasma conditions and the potential within the box as well as the expected dust charge near the center of the box. The calculated potential and dust charge are used to construct acceleration maps for the dust, which are compared to experimentally measured acceleration of the dust within the box.
2019-07-01T00:00:00ZSelf-diffusion in two-dimensional quasi-magnetized rotating dusty plasmasHartmann, PeterReyes, J. C.Kostadinova, Eva Georgieva, 1992-Matthews, Lorin Swint.Hyde, Truell Wayne.Dzhumagulova, K. N.Masheyeva, R. U.Ramazanov, T. S.Ott, T.kahlert, H.Bonitz, M.Korolov, I.Donko, Zoltanhttps://hdl.handle.net/2104/106402022-08-16T17:01:52Z2019-01-10T00:00:00Zdc.title: Self-diffusion in two-dimensional quasi-magnetized rotating dusty plasmas
dc.contributor.author: Hartmann, Peter; Reyes, J. C.; Kostadinova, Eva Georgieva, 1992-; Matthews, Lorin Swint.; Hyde, Truell Wayne.; Dzhumagulova, K. N.; Masheyeva, R. U.; Ramazanov, T. S.; Ott, T.; kahlert, H.; Bonitz, M.; Korolov, I.; Donko, Zoltan
dc.description.abstract: The self-diffusion phenomenon in a two-dimensional dusty plasma at extremely strong (effective) magnetic fields is studied experimentally and by means of molecular dynamics simulations. In the experiment the high magnetic field is introduced by rotating the particle cloud and observing the particle trajectories in a corotating frame, which allows reaching effective magnetic fields up to 3000 T. The experimental results confirm the predictions of the simulations: (i) superdiffusive behavior is found at intermediate timescales and (ii) the dependence of the self-diffusion coefficient on the magnetic field is well reproduced.
2019-01-10T00:00:00Z