A5033742954- Fluid Dynamics and Turbulent Flows
- Magnetic confinement fusion research
- Lattice Boltzmann Simulation Studies
- Ionosphere and magnetosphere dynamics
- Fluid Dynamics and Vibration Analysis
- Laser-Plasma Interactions and Diagnostics
- Plasma Diagnostics and Applications
- Particle accelerators and beam dynamics
- Fluid Dynamics and Heat Transfer
- Solar and Space Plasma Dynamics
- Particle Dynamics in Fluid Flows
- Particle Accelerators and Free-Electron Lasers
- Analytical Chemistry and Sensors
- Mass Spectrometry Techniques and Applications
- Atomic and Subatomic Physics Research
- Characterization and Applications of Magnetic Nanoparticles
- Superconducting Materials and Applications
- Fluid Dynamics Simulations and Interactions
- Magneto-Optical Properties and Applications
- Space Exploration and Technology
- Planetary Science and Exploration
- Ion-surface interactions and analysis
- Pickering emulsions and particle stabilization
- Micro and Nano Robotics
- Fluid Dynamics and Mixing
Seattle University
2007-2022
Lawrence University
2002
University of Wisconsin–Madison
1998-2001
Abstract The control of matter motion at liquid–gas interfaces opens an opportunity to create two-dimensional materials with remotely tunable properties. In analogy optical lattices used in ultra-cold atom physics, such can be created by a wave field capable dynamically guiding into periodic spatial structures. Here we show experimentally that structures realized the macroscopic scale on liquid surface using rotating waves. angular momentum is transferred floating micro-particles, them along...
Improved confinement has been achieved in the MST through control of poloidal electric field, but it is now known that improvement limited by bursts an edge-resonant instability. Through refined field control, plus toroidal we have suppressed these bursts. This led to a total beta 15% and reversed-field-pinch-record estimated energy time 10 ms, tenfold increase over standard value which for first substantially exceeds scaling characterized most reversed-field-pinch plasmas.
Plasma flow velocity fluctuations have been directly measured in the high-temperature magnetically confined plasma Madison Symmetric Torus (MST) Reversed-Field Pinch (RFP) [R. N. Dexter et al., Fusion Technol. 19, 131 (1991)]. These measurements show that are correlated with magnetic field such electromotive force 〈ṽ×B̃〉 approximately balances parallel Ohm’s law, E∥+〈ṽ×B̃〉∥=ηJ∥. This initial measurement is subject to limitations of spatial localization and other uncertainties, but evidence...
The fluctuation-induced dynamo <v x b> has been investigated by direct measurement of v and b in the edge a reversed-field pinch is found to be significant balancing Ohm's law. velocity fluctuations producing emf have poloidal mode number m = 0, consistent with MHD calculations contrast core 1 dynamo. exhibit parity relative their resonant surface predicted linear theory.
A novel insertable probe for local measurements of equilibrium and fluctuating plasma ion flow velocity temperature via Doppler spectroscopy is described. Optical radiation collected by two fused silica fiber optic bundles with perpendicular viewlines. Spatial resolution about 5 cm achieved terminating each view an optical dump. The light transported the to a high-resolution spectrometer. Two components are measured simultaneously—the radial along insertion component (which can be varied...
Electron plasmas are trapped in a novel “partially” toroidal (or “C”-shaped) trap designed to study issues of equilibrium, stability, and confinement nonneutral plasmas. Plasmas with densities as high 3.3×106 cm−3 decay on 100 μs timescale 196 G magnetic field. Successful trapping dense electron requires the application strong horizontal electric field (5–10 V/cm). The time scales 32 power Oscillations image charge current grounded probe have frequency that is proportional 1/B roughly vacuum...
Auxiliary edge current drive is routinely applied in the Madison Symmetric Torus [R. N. Dexter, D. W. Kerst, T. Lovell et al., Fusion Technol. 19, 131 (1991)] with goal of modifying parallel profile to reduce current-driven magnetic fluctuations and associated particle energy transport. Provided by an inductive electric field, successfully reduces First-time measurements modified reveal that, relative discharges without auxiliary drive, density decreases. This decrease explicable terms newly...
A novel experiment to investigate fluid dynamics in quasi-two-dimensional flows has been built. soap film is suspended horizontally an annular channel with a rotating outer boundary, providing mean flow shear, and vortex array forced electromagnetically. The will sheared stability the effect of shear on local vorticity coherent structures. Particle image velocimetry measurements demonstrate production induced vortices.
Maxwell's demon is an entity in a 150-year-old thought experiment that paradoxically appears to violate the second law of thermodynamics by reducing entropy without doing work. It has increasingly practical implications as advances nanomachinery produce devices push thermodynamic limits imposed law. A well-known explanation claiming information erasure restores compliance fails resolve paradox because it assumes