I am presently an Associate Professor in the Department of Physics and Astronomy at the University of Iowa, after a four-year postdoc as an Assistant Professional Research Astronomer in the Department of Astronomy at the University of California, Berkeley, from 2004 to 2008.
Kinetic plasma turbulence is my primary research interest, with an emphasis on high-performance computational studies of turbulence in space and astrophysical plasmas. I am the lead scientist on development of AstroGK, a new gyrokinetic simulation code for astrophysical plasmas.
Although my primary research direction is performing massively parallel, nonlinear gyrokinetic simulations to understand better astrophysical turbulence, I also work on the development of simplified analytical models to study the turbulent cascade of energy in the kinetic and to examine the thermodynamics of the plasma in the solar wind. In addition to this, I also work with scientists dedicated to designing, building, and operating instruments for satellite measurements of the turbulent plasmas in space, focusing in particular on analysis of satellite data. Finally, I am involved in the use of AstroGK for the design and interpretation of basic laboratory experiments on plasma turbulence conducted at the Large Plasma Device (LAPD) at UCLA.
Plasma Theory and Computation Group
I lead the Plasma Theory and Computation Group at the University of Iowa. In addition to scientific collaborations with other University of Iowa faculty members, including Professors Fred Skiff, Craig Kletzing, and Don Gurnett, I oversee my own postdoctoral researchers and graduate students. The current members of the group are
Jason TenBarge, Postodoctoral Researcher:
Jason completed his Ph.D. at the University of Texas under the guidance of Professor Richard Hazeltine. His Ph.D. thesis explored the effect of pressure anisotropy on relativistic slow-mode shocks, with an emphasis on the application to astrophysical systems. At the University of Iowa he has commenced a research program to use high-performance gyrokinetic numerical simulations to examine the heating of ions in low beta plasmas, with relevance to the heating of the solar corona and the turbulent heating of bulk ions in burning fusion plasmas.
Kevin Nielson, Fifth Year Graduate Student:
Kevin is currently using AstroGK in the attempt to model basic laboratory experiments on plasma turbulence conducted at the Large Plasma Device (LAPD) at UCLA. These experiments aim to explore the nonlinear interactions that occur between counter-propogating Alfven waves, the fundamental building block of low-frequency plasma turbulence. He has completed an initial study to demonstrate the validity of AstroGK simulations in the modeling of the linear physics of kinetic and inertial Alfven waves in the semi-collisional conditions of the LAPD. Next he will be exploring the nonlinear evolution of colliding Alfven waves in a simplified geometry to help establish the design parameters for proposed experiments at the LAPD.
Kris Klein, Second Year Graduate Student:
Kris is a new graduate student working on a starter project to construct single-point time series using data from analytical models and simulation data occuring when a moving probe samples a plasma. Such reduced data sets are directly comparable to the single-point measurements made by satellites in the super-Alfvenic solar wind, and will ultimately be used to analyze data from AstroGK numerical simulations.