Koepke Group

Space consists predominantly of ionized gas, known as plasma. One of the outstanding issues in space plasma physics is the role of plasma waves and instabilities in the transport of mass, momentum, and energy in space plasmas. The large-scale plasma flow in space creates conditions that generate plasma waves at relatively small spatial and temporal scales as well as large scales. The small spatial scales of the waves are typically from a few centimeters to a few hundreds of meters and the corresponding temporal scales are from a few microseconds to slightly less than a second. The large-scale plasma flows have scale lengths from a few thousands of kilometers to several Earth radii, and the temporal scales range from about an hour to days and the associated waves have corresponding scales, for example millihertz. The small-scale turbulence (microscopic processes) significantly modifies the large-scale flow and laboratory experiments performed on the WVU Q Machine document some of the processes in play.

Our laboratory results verified important aspects of predicted plasma instabilities used in theoretical models of space plasma processes. The characteristics of these instabilities differ in significant ways from all previous experimentally identified instabilities. By validating certain aspects of the existing theory, discovering new properties of the instability mechanism, and motivating and guiding the extension and revision of other aspects of the existing theory, our laboratory results contribute to a better understanding of space dynamics and equilibria. Several space plasma researchers have cited our work on velocity-shear-driven plasma instabilities in explaining the central role played by this novel instability mechanism in the most common and intense ion heating in the auroral ionosphere.

New elements in our space-related lab experiment-based research program are (1) non-traveling, non-oscillating electromagnetic wavelike structuring, known as the stationary inertial Alfven wave, in auroral plasma, (2) atomic spectroscopic investigation of high-energy-density plasma sharing density and temperature parameters with astrophysical conditions, and (3) exceptionally broadband waves (whistler waves and auroral kilometric radiation) in the Earth’s magnetosphere.

A second thrust of my research is nonlinear dynamics, particularly in the area of driven oscillators. We have experimentally confirmed the theoretical model of a periodic nonlinear process known as periodic pulling, the measurable signatures of which have sometimes been mis-attributed to turbulent processes. We have demonstrated the spatio-temporal nature of this phenomenon in plasmas. Present investigations on driven nonlinear oscillators focus on spatio-temporal and nonstationary aspects of the periodic pulling process. These studies are being used to interpret mode transitions in plasma waves and may be applicable to mode transitions in hydrodynamics.

New elements in our nonlinear-dynamics-related experiments are (1) coupling of toroidal Alfven eigenmodes in tokamak plasma used in magnetic-confinement fusion research and (2) signatures of fractal diffusion, intermittency, and non-modal effects in turbulence-induced transport observed at the plasma-torus boundary in helimak, heliac, stellarator, and tokamak plasma devices.

A third thrust of my research is charging mechanisms associated with dust grains in dusty plasma and with granules in gas-solid multiphase media. We are investigating high-magnetic-field confinement in a 4-Tesla dusty plasma experiment at Auburn University wherein the grains are expected to execute gyromotion within the experimental chamber. In work being carried out at the National Energy Technology Laboratory in Morgantown, we are investigating hydrodynamics and electrostatics in gas-solid multiphase fluid systems in an attempt to quantify and model the influence of materials and operating conditions on granular charging in circulating-loop fluidized beds. Triboelectric charging can have adverse effects on performance in industrial settings and may also create safety hazards such as arcs and explosions. A separate focus is evaluating methods to reduce or utilize the charges generated by the system.

A fourth thrust of my research is fundamental processes of chemically reactive plasmas interacting with multiphase and multifunctional surfaces including liquids, solids, and particles, with emphasis on atmospheric-pressure systems.

Awards and Honors

Visiting Professor, University of Strathclyde, Glasgow, UK
Affiliated Member, DOE-NNSA Center for Astrophysical Plasma Properties 2017-19
Affiliated Member, DOE-SC Center for Predictive Control of Plasma Kinetics since 2009
Chair of FESAC, June 2013 – June 2016
Chair of APS Division of Plasma Physics, 2013-14; Chair-Elect 2012-13; Vice Chair 2011-12
Chair of APS Division of Plasma Physics Annual Meeting Program Committee 2013
Chair of APS-Fellow Selection Committee, Division of Plasma Physics, 2012
Reviewer, DOE Office of Science, Office of Workforce Development of Teachers and Scientists inaugural review, 2012
Member of OMEGA Laser User Group executive board, 2012-2020; Chair 2018-2020
ExCom Sec-Elect/Secretary/Past-Sec of APS-Gaseous Electronics Conference 2016-2018
Member of DIII-D program advisory committee, 2012-2015; Chair 2013-2015
Member of FESAC MFE Priorities subcommittee, 2012-2013
Acting Director and Senior Scientific Coordinator, Fusion Energy Sciences Research Division, Office of Science, U.S. Department of Energy, Washington, DC, 2010-2011
Affiliated Professor, Royal Institute of Technology (KTH), Stockholm, Sweden, 2007-10
U.S. Member, International Union for Pure and Applied Physics, 2005-2011
Deputy Editor, Plasma Physics and Controlled Fusion, 2005-present
Associate Editor, Journal of Plasma Physics, 2006-2009
Robert C. Byrd Professorship for outstanding achievements and leadership in research (WVU Research Corporation), title awarded in 2005
Fellow of the Institute of Physics (United Kingdom), title awarded in 2006
Fellow of the Japanese Society for the Promotion of Science, title awarded in 2005
Fellow of the American Physical Society, title awarded in 2004
Distinguished Lecturer in Plasma Physics (American Physical Society’s Division of Plasma Physics), title awarded in 2001
WVU Benedum Distinguished Scholar, title awarded in 2000
Office of Naval Research Young Investigator, title awarded in 1987
Selected Publications

"Maser radiation from collisionless shocks: Application to astrophysical jets," D. Speirs, K. Ronald, A. Phelps, M. Koepke, R. Cairns, A. Rigby, F. Cruz, R. Trines, R. Bamford, B. Kellett, B. Albertazzi, J. Cross, F. Fraschetti, P. Graham, P. Kozlowski, K. Kuramitsu, F. Miniati, T. Morita, M. Oliver, B. Reville, Y. Sakawa, S. Sarkar, C. Spindloe, M. Koenig, L. Silva, D. Lamb, P. Tzeferacos, S. Lebedev, G. Gregori, R. Bingham, High Power Laser Sci. Engng, 7, e17 (2019).

"Interrelationship between lab, space, astrophysical, magnetic-fusion, and inertial-fusion plasma experiments," M. Koepke, Atoms 2019, 7(1), 35; https://doi.org/10.3390/atoms7010035

"Experimental benchmark of kinetic simulations of capacitively coupled plasmas in molecular gases," Z. Donko, A. Derzsi, I. Korolov, P. Hartmann, S. Brandt (graduate student), J. Schulze, B. Berger, M. Koepke, B. Bruneau, E. Johnson, T. Lafleur, J. P. Booth, A. Gibson, D. O’Connell, T. Gans, Plasma Phys. Contr. Fusion 60, 014010 (2018).

"Probe measurements of electron energy spectrum and plasma-wall interaction in Helium/air micro-plasma at atmospheric pressure," S F Adams, V I Demidov, A L Hensley, M E Koepke, I P Kurlyandskaya, J A Miles and B A Tolson, 7th International Workshop and Summer School on Plasma Physics, J Phys.: Conf. Ser. 982, 012013 (2018).

"Feasibility study for implementing an optical Thomson scattering system for studying photoionized plasmas on Z," P. M. Kozlowski, R. C. Mancini, and M. E. Koepke, IEEE Trans. on Plasma Science 46, 3912 – 3921 (2018).

"Experimental benchmarks of kinetic simulations of capacitively coupled plasmas in molecular gases," Donkó, Derzsi, Korolov, Hartmann, Brandt, Schulze, Berger, Koepke, Bruneau, Johnson, Lafleur, Booth, Gibson, O’Connell, Gans, Plasma Phys. Contr. Fusion 60, 014010 (2017).

"Radiation from an electron beam in magnetized plasma: Excitation of a whistler mode wave packet by interacting, higher-frequency, electrostatic-wave eigenmodes," N. Brenning, I. Axnas, M. Koepke, M. Raadu, E. Tennfors, Plasma Phys. Contr. Fusion 59, 124006 (2017).

"Enhanced power coupling efficiency in inductive discharges with RF substrate bias driven at consecutive harmonics with adjustable phase," B. Berger, T. Steinberger, E. Schüngel, M. Koepke, T. Mussenbrock, P. Awakowicz, and Julian Schulze, Appl. Phys. Lett. 111, 201601 (2017).

"Predictions for gyro-phase drift in MDPX," J. J. Walker, M. E. Koepke, and M. I. Zimmerman, Phys. Plasmas 23, 103707 (2016), http://doi.org/10.1063/1.4966202

"Laboratory evidence for stationary inertial Alfvén waves," M E Koepke, S M Finnegan, S Vincena, D J Knudsen, S H Nogami, and D Vassiliadis, Plasma Physics and Controlled Fusion 58, 084006 (2016), Published 15 July 2016, http://dx.doi.org/10.1088/0741-3335/58/8/084006

"Electron power absorption dynamics in capacitive radio frequency discharges driven by tailored voltage waveforms in CF4," S Brandt, B Berger, E Schüngel, I Korolov, A Derzsi, B Bruneau, E Johnson, T Lafleur, D O'Connell, M Koepke, T Gans, J-P Booth, Z Donkó, and J Schulze, Plasma Sources Science and Technology 25, 045015 (2016), http://dx.doi.org/10.1088/0963-0252/25/4/045015

"A computationally assisted spectroscopic technique to measure secondary electron emission coefficients in radio frequency plasmas," M Daksha, B Berger, E Schuengel, I Korolov, A Derzsi, M Koepke, Z Donkó and J Schulze, Journal of Physics D: Applied Physics 49, 234001 (2016), http://dx.doi.org/10.1088/0022-3727/49/23/234001

"Control of plasma properties in a short direct-current glow discharge with active boundaries," S. F. Adams, V. I. Demidov, E. A. Bogdanov, M. E. Koepke, A. A. Kudryavtsev, and I. P. Kurlyandskaya, Physics of Plasmas 23, 024501 (2016) 10.1063/1.4941259

'Erratum: "Control of plasma properties in a short direct-current glow discharge with active boundaries", S. F. Adams, V. I. Demidov, E. A. Bogdanov, M. E. Koepke, A. A. Kudryavtsev, and I. P. Kurlyandskaya, Phys. Plasmas 23, 024501 (2016)], Physics of Plasmas 23, 109901 (2016); https://doi.org/10.1063/1.4964670.

Suprathermal electron energy spectrum and nonlocally affected plasma-wall interaction in helium/air micro-plasma at atmospheric pressure, V. I. Demidov, S. F. Adams, J. A. Miles, M. E. Koepke, and I. P. Kurlyandskaya, Phys. Plasmas 23, 103508 (2016), http://doi.org/10.1063/1.4964721

"Dynamics of atomic kinetics in a pulsed positive-column discharge at 100 Pa," J B Franek, S H Nogami, M E Koepke, V I Demidov, and E V Barnat, Plasma Physics and Controlled Fusion 59, 014005 (2016). http://dx.doi.org/10.1088/0741-3335/59/1/014005

Predictions for gyro-phase drift in MDPX, J. J. Walker, M. E. Koepke, and M. I. Zimmerman, Physics of Plasmas 23, 103707 (2016), Published Online: October 2016, Accepted: October 2016, http://doi.org/10.1063/1.4966202

"Reply to comment on 'Correlating metastable-atom density, reduced electric field, and electron energy distribution in the post-transient stage of a 1 Torr argon discharge' 2015 Plasma Sources Sci. Technol. 24 034009," J B Franek, S H Nogami, V I Demidov, M E Koepke, and E V Barnat, Plasma Sources Science and Technology 25, 038002 (2016), http://dx.doi.org/10.1088/0963-0252/25/3/038002

"Electron heating dynamics in capacitive radio-frequency discharges driven by tailored voltage waveforms in CF4," S. Brandt, B. Berger, E. Schuengel, I. Korolov, A. Derzsi, B. Bruneau, E. Johnson, T. Lafleur, D. O'Connell, M. Koepke, T. Gans, J.-P. Booth, Z. Donko, J. Schulze, Plasma Sources Sci. Technol. 25, 045015 (2016).

"Control of plasma properties in a short direct-current glow discharge with active boundaries," S. F. Adams, E. A. Bogdanov, V. I. Demidov, M. E. Koepke, A. A. Kudryavtsev, and I. P. Kurlyandskaya, Phys. Plasmas 23, 024501 (2016); https://doi.org/10.1063/1.4941259.

“Correlating metastable-atom density, reduced electric field, and electron energy distribution in the post-transient stage of a 1-torr argon discharge", J. Franek, S. Nogami, E. Barnat, V. Demidov, M. Koepke, Plasma Sources Sci. and Techn. 24, 034009 (2015).

“Power supply and impedance matching to drive technological radio-frequency plasmas with customized voltage waveforms”, J. Franek, S. Brandt, B. Berger, M. Liese, M. Barthel, E. Schuengel, and J. Schulze, Rev. Sci.Instrum. 86, 053504 (2015).

“Experimental investigations of electron heating dynamics and ion energy distributions in capacitive discharges driven by customized voltage waveforms”, B. Berger, S. Brandt, J. Franek, E. Schuengel, M. Koepke, T. Mussenbrock, and J. Schulze, J. Applied Physics 118, 223302 (2015)

"Measurements of low-energy electron reflection at a plasma boundary," V. Demidov, S. Adams, I. Kaganovich, M. Koepke, I. Kurlyandskaya, Phys. Plasmas 22, 104501 (2015).

"Sharp transition between two regimes of operation of dc discharge with two anodes and thermionic emission from cathode," A Mustafaev, V Demidov, I Kaganovich, M Koepke, A. Grabovskiy, Phys. Plasmas 21, 053508 (2014). http://dx.doi.org/10.1063/1.4876928

"Analytical model for gyro-phase drift arising from abrupt inhomogeneity," J. J. Walker, M. E. Koepke, M. I. Zimmerman, W. M. Farrell and V. I. Demidov, Journal of Plasma Physics 80, 395 – 404 (2014). DOI: http://dx.doi.org/10.1017/S0022377813001359

"Ion-temperature-gradient sensitivity of the hydrodynamic instability caused by shear in the magnetic-field-aligned plasma flow," V. V. Mikhailenko, V. S. Mikhailenko, Hae June Lee, and M. E. Koepke, Phys. Plasmas 21, 072117 (2014). doi: 10.1063/1.4890297

"The temporal evolution of the kinetic drift-Alfven instability of plasma shear flow," V.V. Mikhailenko, V.S. Mikhailenko, Hae June Lee, and M.E. Koepke, Phys. Plasmas 21, 032118 (2014); https://doi.org/10.1063/1.4869094

"Non-modal analysis of the diocotron instability for cylindrical geometry with conducting boundary," V.V. Mikhailenko, Jin Seok Kim, Younghyun Jo, V.S. Mikhailenko, and Hae June Lee, Phys. Plasmas 21, 052105, (2014)

Ion-temperature-gradient sensitivity of the hydrodynamic instability caused by shear in the magnetic-field-aligned plasma flow, V.V. Mikhailenko, V.S. Mikhailenko, Hae June Lee and M.E. Koepke, Physics of Plasmas, vol.21, Issue 7, 072117, (2014);

"Quasiperiodic mode hopping in competing ionization waves," P. M. Miller, M. E. Koepke, H. Gunell, Plasma Physics and Controlled Fusion 56, 015003 (2014), doi:10.1088/0741-3335/56/1/015003.

"Determination of Ar metastable atom densities in Ar and Ar/H2 inductively coupled low temperature plasmas," N. Fox-Lyon, A. Knoll, J. Franek, V. Demidov, V. Godyak, M. Koepke, G. Oehrlein, J. Phys. D: Appl. Phys. 46, 485202 (2013).

"Modeling a short dc discharge with thermionic cathode and auxiliary anode for plasma stabilization," E. Bogdanov, V.I. Demidov, I.D. Kaganovich, M.E. Koepke, and A.A. Kudryavtsev, Phys. Plasmas 20, 101605 (2013); http://dx.doi.org/10.1063/1.4823464.

"Kinetic effects of ExB sheared flow on the hydrodynamic drift instabilities," V. V. Mikhailenko, V. S. Mikhailenko, Hae June Lee, M. E. Koepke, Plasma Phys. Control. Fusion 55, 085018 (2013), doi:10.1088/0741-3335/55/8/085018.

"Metastable atom and electron density diagnostic in the initial stage of a pulsed discharge in Ar and other rare gases by emission spectroscopy," S F Adams, E A Bogdanov, V I Demidov, M E Koepke, A A Kudryavtsev, and J M Williamson, Phys. Plasmas 19, 023510 (2012), doi 10.1063/1.3686132.

"Control of current and voltage oscillations in a short dc discharge making use of external auxiliary electrode," A S Mustafaev, V I Demidov, I Kaganovich, S F Adams, M E Koepke, A Grabovskiy, Rev. Sci. Instrum 83, 103502 (2012), doi 10.1063/1.4757111

"Excitation mechanisms and spectral properties of the ion-cyclotron parallel-velocity shear driven instability," V.S. Mikhailenko, D.V. Chibisov, M. E. Koepke, J. Geophys. Res. 117, A04322 (2012), doi 10.1029/2011JA017489

"Characterisation of a Penning discharge for investigation of auroral radio wave generation mechanisms," S L McConville, M E Koepke K M Gillespie, K Matheson, C G Whyte, C W Robertson and D C Speirs, Plasma Phys. Contr. Fusion, Plasma Phys. Control. Fusion 53, 124020 (2011), 9 pages, doi:10.1088/0741-3335/53/12/124020.

"Numerical experiments on plasmoids entering a transverse magnetic field," H. Gunell, J. Walker, M. Koepke, T. Hurtig, N. Brenning, and H. Nilsson, Physics of Plasmas 16, 112901 (Nov 2009).

“Quasiperiodic mode hopping in competing ionization waves,” P. M. Miller, M. E. Koepke, H. Gunell, Plasma Physics and Controlled Fusion 56, 015003 (2014), doi:10.1088/0741-3335/56/1/015003.

“Signature of gyro-phase drift,” M. E. Koepke, J. J. Walker, M. I. Zimmerman, W. M. Farrell, V. I. Demidov, J Plasma Phys., Volume 79, Special Issue 06, 1099 – 1105 (December 2013); doi.10.1017/S0022377813001128.

“Determination of Ar metastable atom densities in Ar and Ar/H2 inductively coupled low temperature plasmas,” N. Fox-Lyon, A. Knoll, J. Franek, V. Demidov, V. Godyak, M. Koepke, G. Oehrlein, J. Phys. D: Appl. Phys. 46, 485202 (2013).

“Modeling a short dc discharge with thermionic cathode and auxiliary anode for plasma stabilization,” E. Bogdanov, V.I. Demidov, I.D. Kaganovich, M.E. Koepke, and A.A. Kudryavtsev, Phys. Plasmas 20, 101605 (2013); http://dx.doi.org/10.1063/1.4823464.

“Kinetic effects of ExB sheared flow on the hydrodynamic drift instabilities,” V. V. Mikhailenko, V. S. Mikhailenko, Hae June Lee, M. E. Koepke, Plasma Phys. Control. Fusion 55, 085018 (2013), doi:10.1088/0741-3335/55/8/085018.

“Excitation mechanisms and spectral properties of the ion-cyclotron parallel-velocity shear driven instability,” V S Mikhailenko, D V Chibisov, M E Koepke, J. Geophys. Res. 117, A04322 (2012).

“Control of current and voltage oscillations in a short dc discharge making use of external auxiliary electrode,” A S Mustafaev, V I Demidov, I Kaganovich, S F Adams, M E Koepke, A Grabovskiy, Rev. Sci. Instrum. 83, 103502 (2012).

“Metastable atom and electron density diagnostic in the initial stage of a pulsed discharge in Ar and other rare gases by emission spectroscopy,” S F Adams, E A Bogdanov, V I Demidov, M E Koepke, A A Kudryavtsev, and J M Williamson, Phys. Plasmas 19, 023510 (2012).

“Characterisation of a Penning discharge for investigation of auroral radio wave generation mechanisms,” S L McConville, M E Koepke K M Gillespie, K Matheson, C G Whyte, C W Robertson and D C Speirs, Plasma Phys. Contr. Fusion 53, 124020 (2011).

“Multi-objective physiological indicators based on complementary complexity measures: Application to early diagnostics and prediction of acute events, ” V. V. Gavrishchaka, M. E. Koepke, O. Senyukova, and A. I. Kryuchkova, 33rd Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC ’11), Boston, MA, 2011.

“Short DC discharge with wall probe as a gas analytical detector”, V. I. Demidov, S. F. Adams, J. Blessington, M. E. Koepke, and J. M. Williamson, Contrib. Plasma Phys. 50, 808-813, 2010.

“Boosting-based discovery of multi-component physiological indicators: Applications to express diagnostics and personalized treatment optimization” V. V. Gavrishchaka, M. E. Koepke, and O. N. Ulyanova, 1st ACM International Conference on Health Informatics (IHI2010) 11-12 November 2010, Arlington, VA, ACM978-1-4503-0030-8/10/11.

“Magnetically insulated baffled probe for real-time monitoring of equilibrium and fluctuation values of space potentials, electron and ion temperatures, and densities,” V. I. Demidov, M. E. Koepke, and Y. Raitses, Rev. Sci. Instrum. 81, 10E129 (October 2010).

“Ensemble learning frameworks for the discovery of multi-component quantitative models in biomedical applications,” V.V. Gavrishchaka, M.E. Koepke, O.N. Ulyanova, Second International Conference on Computer Modeling and Simulation, Sanya, China, vol. 4, 329-336, 2010.

“Numerical experiments on plasmoids entering a transverse magnetic field,” H. Gunell, J. Walker, M. Koepke, T. Hurtig, N. Brenning, and H. Nilsson, Phys. Plasmas 16, 112901, 2009.

“A two-fluid model describing the finite conductivity, stationary Alfven wave in anisotropic plasma,” S. M. Finnegan, M. E. Koepke, D. J. Knudsen, Nonlin. Processes Geophys. 15, 957-964 (2008).

“Laboratory plasma physics,” M. E. Koepke, in Recent Research Developments in Plasma Physics, 2007, J. Weiland, ed. (Transworld Research Network, Kerala, India, 2008) chapter 7 (28 book pages, invited chapter).

“Interrelated laboratory and space plasma experiments,” M. E. Koepke, Reviews of Geophysics 46, RG3001, doi:10.1029/2005RG000168, 16 July (2008).

“The dispersive Alfven wave in the time-stationary limit with a focus on collisional and warm-plasma effects,” S. M. Finnegan, M. E. Koepke, and D. J. Knudsen, Phys. Plasmas 15, 052108 (2008).

“Integrated campaign to study stationary Alfven wave in the laboratory and space regimes,” M. E. Koepke, S. M. Finnegan, S. Vincena, D. J. Knudsen, C. Chaston, Plasma Physics and Controlled Fusion 50, 074004 (2008).

“Interrelationship between plasma phenomena in the laboratory and in space,” M. E. Koepke, Plasma Physics and Controlled Fusion 50, 070201 (2008).

“Spectral characteristics of the collisional stationary Alfven wave in the laboratory and space regimes,” S. M. Finnegan, M. E. Koepke, and D. J. Knudsen, Plasma Physics and Controlled Fusion 50, 074005 (2008).

“Simulations of a plasmoid penetrating a magnetic barrier,” H. Gunell, T. Hurtig, H. Nilsson, M. Koepke, and N. Brenning, Plasma Physics and Controlled Fusion 50, 074013 (2008).

“Shear driven waves in the induced magnetosphere of Mars,” H. Gunell, U. V. Amerstorfer, H. Nilsson, C, Grima, M. Koepke, M. Franz, J. D. Winningham, R. A. Frahm, J.-A. Sauvand, A. Fedorov, V. Erkaev, H. K. Biernat, M. Holmstram, R. Lundin, and S. Barabash, Plasma Physics and Controlled Fusion 50, 074018 (2008).

“Investigation of a radio-frequency inductive-coupled-plasma discharge afterglow in noble gases,” C. A. DeJoseph, V. I. Demidov, J. C. Blessington, and M. E. Koepke, J. Phys. B: Atomic, Molecular, and Optical Physics, 40, 3823-3833 (October 2007).

“Dynamics of small dust clouds trapped in a magnetized anodic plasma,” I. Pilch, A. Piel, T. Trottenberg, and M. E. Koepke, Phys. Plasmas, 12, 123704 (December 2007, 8 pages).

“Laboratory plasma physics,” M. E. Koepke, in Recent Research Developments in Plasma Physics, 2007, J. Weiland, ed. (Transworld Research Network, Kerala, India, 2008) chapter 7 (28 book pages, invited chapter).

“Simultaneous, co-located parallel-flow shear and perpendicular-flow shear in low-temperature, ionospheric-plasma relevant, laboratory plasma,” M. E. Koepke and E. W. Reynolds, Plasma Phys. Controlled Fusion 49, A145-A157 (May 2007).

“Investigation of a radio-frequency inductive-coupled-plasma discharge afterglow in noble gases,” C. A. DeJoseph, V. I. Demidov, J. C. Blessington, and M. E. Koepke, J. Phys. B: Atomic, Molecular, and Optical Physics (J. Phys. B: At. Mol. Opt. Phys.), 40, 3823-3833 (2007).

“Baffled-probe cluster for simultaneous, single-point monitoring of magnetized plasma fluctuations,” M. E. Koepke, V. I. Demidov, S. M. Finnegan, and E. W. Reynolds, Contrib. Plasma Phys. 46, 395-401 (2006).

“Inhomogeneity scale lengths in a magnetized, low temperature, collisionless, Q-machine plasma column containing perpendicular-velocity shear,” E. W. Reynolds, M. E. Koepke, J. J. Carroll, and S. Shinohara, Phys. Plasmas 13, 092106 (2006). 12 pages

“Electron parallel-flow shear driven low-frequency electromagnetic modes in collisionless magnetoplasma,” P. K. Shukla, B. Eliasson, and M. Koepke, Phys. Plasmas 13, 052115 (2006). 6 pages

“Radiation from an electron beam in a magnetized plasma: Whistler mode wave packets,” N. Brenning, I. Axnas, M. A. Raadu, E. Tennfors, and M. Koepke, J. Geophys. Res. 111, A11212, doi:10.1029/2006JA011739 (2006).

“Velocity-shear-driven drift waves with simultaneous modes in a barium-ion Q-machine plasma,” T. Kaneko, E. Reynolds, R. Hatakeyama, and M. Koepke, Phys. Plasmas, 12, 102106 (2005).

“Laser-induced-fluorescence characterization of velocity shear in a magnetized plasma column produced by a segmented Q-machine source,” E. W. Reynolds, T. Kaneko, M. E. Koepke, and R. Hatakeyama, Phys. Plasmas, 12, 072103 (2005).
“On interrelating laboratory experiments and geoplasma observations,” M. E. Koepke, Plasma Phys. Contr. Fusion, 47, B727-B734 (2005).

“Effect of the bounce orbit’s turning-point location on bounce-resonance Landau damping,” M. E. Koepke, Physica Scripta, T116, 107 (2005). (online article number: t116p01a00107)

“Lower-hybrid cavity density depletions as a result of transverse ion acceleration localized on the gyroradius scale,” D. Knudsen, B. J. J. Block, S. R. Bounds, J. K. Burchill, J. H. Clemmons, J. D. Curtis, A. I. Eriksson, M. E. Koepke, R. F. Pfaff, D. D. Wallis, and N. Whaley, J. Geophys. Res., 109, A04212, doi:10.1029/2003JA010089 (20 April 2004).

“Sheared-flow-driven electrostatic waves in laboratory and space plasmas,” M. E. Koepke, Physica Scripta, T107, 182-187 (2004).

“Utility of a baffled probe for applications to edge plasma and turbulence characterization in stellarator plasma,” W. Guttenfelder, C. Lechte, M. E. Koepke, and V. I. Demidov, Rev. Sci. Instrum., 75, 3622 (2004).

“Utility of a baffled probe for measurements of oscillations in magnetized plasma,” V.I. Demidov, S. M. Finnegan, M. E. Koepke, and E. W. Reynolds, Contrib. Plasma Physics, 44, 689-694 (2004).

“On the role of ion-temperature anisotropy in the growth and propagation of ion-acoustic waves,” C. Teodorescu, M.E. Koepke, and E.W. Reynolds, J. Geophys. Res., 108, SMP 25.1 – 25.9 (2003).

“Baffled probe for real-time measurement of space potential in magnetized plasma,” V I Demidov, S M Finnegan, M E Koepke, and E W Reynolds, Rev. Sci. Instrum., 74, 4558 (2003).

“Space-relevant laboratory studies of ion-acoustic and ion-cyclotron waves driven by parallel-velocity shear,” M. E. Koepke, C. Teodorescu, and E. W. Reynolds, Plasma Phys. Contr. Fusion, 45, 869-889 (2003).

“Resonant-to-nonresonant transition in electrostatic ion-cyclotron phase velocity,” J. J. Carroll III, M. E. Koepke, M. W. Zintl, and V. Gavrishchaka, Nonlinear Processes in Geophysics, 10, 131-138 (2003).

“Inverse ion-cyclotron damping: Laboratory documentation and space ramifications,” M. E. Koepke, C. Teodorescu, E. R. Reynolds, C. C. Chaston, C. W. Carlson, J. P. McFadden, and R. E. Ergun, Phys. Plasmas, 10, 1605-1613 (2003).

“On the role of ion-temperature anisotropy in the growth and propagation of shear-modified ion-acoustic waves,” C. Teodorescu, M. E. Koepke, and E. W. Reynolds, J. Geophys. Res., 108, SMP-25 (2003).

“Evidence for thermal anisotropy effects on shear modified ion-acoustic instabilities,” E. E. Scime,
A. M. Keesee, R. S. Spangler, M. E. Koepke, C. Teodorescu, and E. W. Reynolds, Phys. Plasmas, 9, 4399 (2002).

“Observation of inverse ion-cyclotron damping induced by parallel-velocity shear,” C. Teodorescu, E. W. Reynolds, and M. E. Koepke, Phys. Rev. Lett., 89, 105001 (2002).

“Inhomogeneous magnetic-field-aligned ion flow measured in a Q machine,” M. E. Koepke, M. W. Zintl, C. Teodorescu, E. W. Reynolds, G. Wang, and T. N. Good, Phys. Plasmas, 9, 3225 (2002).

“Experimental verification of the shear-modified ion-acoustic instability,” C. Teodorescu, E. W. Reynolds, and M. E. Koepke, Phys. Rev. Lett., 88, 185003 (2002).

“Contributions of Q-machine experiments to understanding auroral particle acceleration processes,” M. E. Koepke, Phys. Plasmas, 9, 2420 (2002).

“Spatio-temporal signatures of periodic pulling during ionization-wave mode transitions,” M. E. Koepke, A. Dinklage, T. Klinger, and C. Wilke, Phys. Plasmas, 8, 1432 (2001).

“Inhomogeneous transverse electric fields and wave generation in the auroral region: A statistical study,” M. Hamrin, M. Andre, G. Ganguli, V. V. Gavrishchaka, M. E. Koepke, M. W. Zintl, N. Ivchenko, T. Karlsson, and J. H. Clemmons, J. Geophys. Res., 106, 10803 (2001).

“Spatio-temporal laser perturbation of competing ionization waves in a neon glow discharge,” K.-D. Weltmann, M. E. Koepke, and C. A. Selcher, Phys. Rev. E., 62, 2773 (2000).

“Laboratory simulation of broadband ELF waves in the auroral ionosphere,” M. E. Koepke, J. J. Carroll III, and M. W. Zintl, J. Geophys. Res., 104, 14397 (1999).

“Broadband electric-field spectral power density associated with electrostatic ion-cyclotron waves,” M. E. Koepke, M. W. Zintl, and J. J. Carroll III, in Physics of Space Plasmas (1998), T. Chang and J. R. Jasperse, eds. (MIT Center for Theoretical Geo/Cosmo Plasma Physics, Cambridge, MA, 1998) p. 221.

“Excitation and propagation of electrostatic ion-cyclotron waves in plasma with structured transverse flow,” M. E. Koepke, J. J. Carroll III, and M. W. Zintl, Phys. Plasmas, 5, 1671 (1998).

“An effect of neutral collisions on the excitation threshold of electrostatic ion-cyclotron waves,” M. E. Koepke, M. W. Zintl, and T. N. Good, Geophys. Res. Lett., 25, 3095 (1998).

“Velocity-shear origin of low-frequency electrostatic ion-gyroresonant waves,” J.J. Carroll III, M. E. Koepke, M. W. Zintl, and V. Gavrishchaka, Geophys. Res. Lett., 25, 3099 (1998).

“Control of ion temperature anisotropy in a helicon plasma, E. Scime, P. Keiter, M. Zintl, M. Balkey, J. Kline, and M. Koepke, Plasma Sources Sci. Technol., 7, 186 (1998).

“Velocity-shear-driven ion-cyclotron waves and associated transverse ion heating,” W. E. Amatucci, D. N. Walker, G. Ganguli, D. Duncan, J. A. Antoniades, J. H. Bowles, V. Gavrishchaka, and M. E. Koepke, J. Geophys. Res., 103, 11711 (1998).

“Simultaneous observation of multiple nonlocal eigenmodes of an inhomogeneity-driven plasma instability,” M. E. Koepke, J. J. Carroll III, M. W. Zintl, C. A. Selcher, and V. Gavrishchaka, Phys. Rev. Lett., 80, 1441 (1998).

“High-order nonlocal formalism for linear analysis of a magnetized multi-species plasma with inhomogeneous flows,” V. V. Gavrishchaka, G. I. Ganguli, P. M. Bakshi, and M. E. Koepke, Phys. Plasmas, 5, 10 (1998).

“A simple Langmuir probe for alkali plasmas,” D. Strele, M. Koepke, R. Schrittwieser, and P. Winkler, Rev. Sci. Instrum., 67, 3751 (1997).

“Perpendicular ion heating by velocity-shear-driven waves,” D. N. Walker, W. E. Amatucci, G. Ganguli, J. A. Antoniades, J. H. Bowles, D. Duncan, V. Gavrishchaka, and M. E. Koepke, Geophys. Res. Lett., 24, 1187 (1997).

“Observation of velocity-shear-driven instabilities in a sodium plasma (invited),” J. J. Carroll III, M. E. Koepke, M. W. Zintl, C. A. Selcher, V. Gavrishchaka, and E. Csomortani in Double Layers – Potential Formation and Related Nonlinear Phenomena in Plasmas (World Scientific, Singapore, 1997) p. 283

“Space-chamber investigations of transverse velocity shear-driven plasma waves,” W. E. Amatucci, D. N. Walker, G. Ganguli, J. A. Antoniades, D. Duncan, J. Bowles, V. Gavrishchaka, and M. E. Koepke in Double Layers – Potential Formation and Related Nonlinear Phenomena in Plasmas (World Scientific, Singapore, 1997) p. 277

“Ion-cyclotron modes in a two-ion-component plasma with transverse-velocity shear,” V. V. Gavrishchaka, M. E. Koepke, and G. Ganguli, J. Geophys. Res., 102, 11653 (1997).

“Periodic nonlinear wave-wave interaction in a plasma discharge with no external oscillatory force,” M. E. Koepke, T. Klinger, F. Seddighi, and A. Piel, Phys. Plasmas, 3, 4421 (1996).

“Plasma response to strongly sheared flow,” W. E. Amatucci, D. N. Walker, J. A. Antoniades, G. Ganguli, D. Duncan, J. H. Bowles, V. Gavrishchaka, and M. E. Koepke, Phys. Rev. Lett., 77, 1978 (1996).

“Dispersive properties of a magnetized plasma with a field-aligned drift and inhomogeneous transverse flow,” V. Gavrishchaka, M. E. Koepke, and G. Ganguli, Phys. Plasmas, 3, 3091 (1996).

“Inhomogeneity scale lengths in the WVU Q machine,” J. J. Carroll and M. E. Koepke, in Physics of Space Plasmas (1995), T. Chang and J. R. Jasperse, eds. (MIT Center for Theoretical Geo/Cosmo Plasma Physics, Cambridge, MA, 1996) p. 625-632.

“Frequency range and spectral width of waves associated with transverse-velocity shear,” V. Gavrishchaka, M. E. Koepke, J. J. Carroll III, W. E. Amatucci, and G. Ganguli, in Cross-Scale Coupling in Space Plasma, Geophysical Monograph Series, vol. 93, Horwitz, Singh, and Burch, eds. (AGU, Washington, D.C., 1995) p. 81-85.

“van der Pol behavior of relaxation oscillations in a periodically driven thermionic discharge,” T. Klinger, F. Greiner, A. Rohde, A. Piel, and M. Koepke, Phys Rev. E, 52, 4316 (1995).

“Velocity-shear-induced ion-cyclotron turbulence: Laboratory identification and space applications,” M. E. Koepke, W. E. Amatucci, J. J. Carroll III, V. Gavrishchaka, and G. Ganguli, Phys. Plasmas, 2, 2523 (1995).

“A segmented disk electrode to produce and control parallel and transverse particle drifts in a cylindrical plasma,” J. J. Carroll III, M. E. Koepke, W. E. Amatucci, T. E. Sheridan, and M. J. Alport, Rev. Sci. Instrum., 65, 2991 (1994).

“Observation of ion-cyclotron turbulence at small values of magnetic field-aligned current,” W. E. Amatucci, M. E. Koepke, J. J. Carroll III, and T. E. Sheridan, Geophys. Res. Lett., 21, 1595 (1994).

“Experimental verification of the inhomogeneous energy-density driven instability,” M. E. Koepke, W. E. Amatucci, J. Carroll, and T. E. Sheridan, Phys. Rev. Lett., 72, 3355 (1994).

“Asymmetric spectral broadening of modulated electrostatic ion-cyclotron waves,” M. E. Koepke, M. J. Alport, T. E. Sheridan, W. E. Amatucci, and J. J. Carroll III, Geophys. Res. Lett., 21, 1011 (1994).

“Observation of small-integer dimensionality in a system with complicated spectra,” M. E. Koepke, T. E. Sheridan, and M. R. Millecchia, in Physics of Space Plasmas (1993), T. Chang and J. R. Jasperse, eds. (MIT Center for Theoretical Geo/Cosmo Plasma Physics, Cambridge, MA, 1994) p. 178.

“Periodic pulling in a driven relaxation oscillator,” T. E. Sheridan, M. E. Koepke, C. A. Selcher, and T. N. Good, in Proc. of SPIE, 2039, 158 (1993).

“Effects of a transverse, localized, electric field on the electrostatic ion-cyclotron instability,” M. E. Koepke, W. E. Amatucci, J. J. Carroll III, M. J. Alport, and T. E. Sheridan, in Auroral Plasma Dynamics, AGU Monograph #80, R. Lysak, ed. (American Geophysical Union, Washington, D.C., 1993) p. 287.

“Self-cleaning Langmuir probe,” W. E. Amatucci, M. E. Koepke, T. E. Sheridan, M. J. Alport, and J. J. Carroll III, Rev. Sci. Instrum., 64, 1352-1356 (1993).

“Effects of periodic pulling on spontaneous oscillations,” M. E. Koepke, T. E. Sheridan, and M. J. Alport, in Physics of Space Plasmas (1992), T. Chang and J. R. Jasperse, eds. (Scientific Publishers, Cambridge, MA, 1992) p. 551.

“Electrostatic ion-cyclotron experiments in the WVU Q machine, M. E. Koepke and W. E. Amatucci, IEEE Trans. Plasma Sci., PS-20, 631 (1992).

“Effect of bounce resonance damping on the harmonics of a plasma microinstability,” M. E. Koepke, Phys. Fluids B, 4, 1193 (1992).

“Experimental verification of periodic pulling in a nonlinear electronic oscillator,” M. E. Koepke and D. M. Hartley, Phys. Rev. A, 44, 6877 (1991).

“Experimental studies of linear high-beta heliac plasma configurations, “C. M. Greenfield, M. E. Koepke and F. L. Ribe, Phys. Fluids B, 2, 133 (1990)

“Theoretical modeling of DCLC radial mode structure measurements,” G. R. Burkhart, P. N. Guzdar, and M. E. Koepke, Phys. Fluids B, 1, 570 (1989).

“Experimental studies of the equilibrium of a linear high beta L=1 stellarator,” E. R. Hedin, M. E. Koepke, and F. L. Ribe, Phys. Fluids, 30, 2885 (1987)

“Experimental studies of the dynamics of a linear high-beta stellarator,” E. R. Hedin, M. E. Koepke, and F. L. Ribe, Phys. Fluids, 30, 3821 (1987)

“Optimizing hot-ion production from a gas-injected washer gun,” M. J. McCarrick, R. F. Ellis, J. H. Booske, and M. Koepke, J. Appl. Phys., 61, 1747 (1987).

“Experimental observation of bounce-resonance Landau damping in an axisymmetric mirror plasma,” M. Koepke, R. F. Ellis, R. P. Majeski, and M. J. McCarick, Phys. Rev. Lett., 56, 1256 (1986)

“Three-dimensional mode structure of the drift cyclotron loss-cone instability in a mirror trap,” M. Koepke, M. J. McCarrick, R. P. Majeski, and R. F. Ellis, Phys. Fluids, 29, 3439 (1986)

“Perpendicular ion energy analyzer for hot ion plasmas,” M. J. McCarrick, R. F. Ellis, M. Koepke, and R. P. Majeski, Rev. Sci. Instrum., 56, 1463 (1985)

“Interaction of lower-hybrid waves with the current-driven ion acoustic instability,” R. P. Majeski, M. Koepke, and R. F. Ellis, Plasma Phys. Contr. Fusion, 26, 373 (1984).

“A preshaping transition coil for a small min-B mirror,” M. Koepke, R. P. Majeski, and R. F. Ellis, IEEETrans. Plasma Sci., PS-11, 299 (1983).