Advancing stellarator physics and fusion energy research
Biography Ali’s research on HSX concentrated on examining superthermal electron dynamics in HSX especially through hard X-ray measurements of the electron superthermal tail produced through second harmonic X-mode ECRH. Ali received his PhD (link to Ali’s dissertation) in the 2005, and began work as an Associate Professor at Zewail City of Science and Technology, Egypt.
Biography Adrian studied the edges of the plasmas in HSX, with a strong emphasis on divertor flows, particle edge fluxes and edge plasma parameters. In particular, comparisons and verification of models of the plasma divertors (EMC3-EIRENE) which at present do not include the effects of local electric fields on the flows and particle fluxes.
Dr. David Anderson was the PI of HSX for its formative years until his retirement as Emeritus Professor in 2023. He was involved with the experiment since its initial design activities in 1990, and is internationally recognized for his expertise in plasma physics and fusion energy. He is a co-founder of Type One Energy, a company focused on developing next-generation stellarators for fusion power.
John studied the effects of quasisymmetry on particle and heat transport in HSX. He did this by measuring the plasma density and temperature profiles using a Thomson scattering system. He also performed extensive three-dimensional modeling of the neutral gas in HSX plasma, which has yielded the particle source rate and neutral density. John received his PhD in Spring of 2007 and went to work at Oak Ridge National Laboratory under a prestigious Wigner Fellowship. John then headed the ORNL plasma physics theory group.
Fernando earned his PhD in electrical engineering in 2022, and is now a fusion scientist at Helion Energy.
Enrico worked to extend the design of magnetic diagnostics on the HSX stellarator. Optimization of the coil placements and field components measured was carried out to guide the implementation of a new array of in-vessel coil diagnostics used for equilibrium reconstruction of the plasma density, pressure and current profiles. Enrico received his PhD in 2014 and began work with Roland Berger Strategy Consultants in Germany.
Biography Chris investigated impurity transport in the HSX Stellarator. He led the development and construction of a laser blow-off impurity injection system, which is currently being used to introduce controlled quantities of impurities into HSX for analysis. Data from this was analyzed using the STRAHL code modified for the non-axisymmetric stellarator geometry. Chris did not …
Biography Carson worked on the SIESTA (Spectral Iterative Equilibrium Solver for Toroidal Applications) code development project with Steve Hirshman and Raul Sanchez of ORNL. SIESTA is a magnetohydrodynamic equilibrium code used for modeling toroidal plasmas in 3D systems. Unlike VMEC, SIESTA does not assume nested magnetic flux surfaces, so equilibria involving magnetic islands and stochastic …
Dionysi started joined the HSX Lab and started his Electrical Engineering PhD in Fall 2021. His passion to pursue fusion power pulled him away from the deployment of autonomous vehicles and he is now starting research on neutral density measurements with H alpha detectors. He completed his undergraduate degrees in electrical and mechanical engineering with a minor in physics from Colorado School of Mines. Outside of school and research, he’s often looking for nice hikes or twisty roads to ride his motorcycle through.
Tom implemented a polarimetry system to evaluate the Stark shift from the diagnostic Hydrogen neutral beam to allow better electric field determination. His thesis was on the addition of neutral damping to the model used to calculate plasma flows and explains the differences seen between the model and the experimental measurements. Tom began work at GE in Minneapolis, MN.
Michael received his Bachelor degree in Physics and Applied Mathematics from the University of Colorado in Boulder, where he did research in lunar geology and plasma wakefield acceleration. He started graduate school at the University of Wisconsin-Madison in the fall of 2019. He completed his PhD in the Nuclear Engineering and Engineering Physics department under his advisor Benedikt Geiger. He does computational research in plasma turbulence optimization for HSX.
Stefan's research on HSX concentrated on examining flows and flow damping in HSX which because of the quasi-symmetry was predicted to allow flows similar to tokamaks. Stefan received his PhD in 2004, and began work at the Princeton Plasma Physics Lab in Princeton, NJ as the Principal Research Physicist.
Wayne completed his PhD and joined HSX as a postdoctoral researcher in 2024. His research is focused on the development of RF and optical diagnostics.
Walter's research on HSX concentrated on examining fluctuations and anomalous transport in HSX especially through comparisons of edge fluctuations measurements with 3-D gyrokinetic modeling. Walter received his PhD in the Winter of 2007, and began work at the Princeton Plasma Physics Lab in Princeton, NJ.
Henrique joined HSX as a graduate student in 2020. He received Bachelor’s degrees in math and electrical engineering at the University of Alaska Anchorage, where he used the PIC code Tech-X VSIM to model a multipole plasma trap. Now he studies turbulence and transport over a range of HSX magnetic topologies. He works on synthetic diagnostic development, diagnostic analysis tools, experimental fluctuation and confinement measurements, and gyrokinetic simulations in GENE. His PhD topic is to experimentally investigate the impact flux-surface-elongated HSX configurations have on trapped-electron-mode turbulence and overall confinement. This project is motivated by computational GENE results that predict reduced growth rates, less coherent mode activity, and improved confinement in elongated configurations.
Sam joined the HSX lab in 2025 as a NEEP PhD student. He earned his bachelor's degree in Physics and Applied Math from Brandeis university with a thesis studying simulations of future particle accelerators. Outside of research and school, Sam enjoys rock climbing, listening and playing along with 90's music on his guitar, and doing trivia with friends.
Thomas started as a graduate student with the HSX group in 2018, and graduated in 2023. He studies stellarator coil and ferromagnetic insert optimization. He is also part of a research group designing the world's first high temperature superconducting stellarator coil, funded by ARPA-E.
Jeremy's focus area was the measurement and modeling of transport at HSX. Jeremy developed the PENTA code with Don Spong from ORNL, which calculates neoclassical transport quantities in stellarators or tokamaks while conserving parallel momentum. Neoclassical calculations predict a large "electron root" radial electric field (Er) in the core of HSX plasmas, with strong radial shear. The neoclassical simulations, coupled with turbulent transport calculations performed by Walter Guttenfelder have been successful in simulating the strongly peaked electron temperature profiles measured during ECR heating. The predicted electric fields and in-surface flows will be compared to ChERS measurements. In 2006 Jeremy implemented a displacement sensor system on HSX and performed structural modeling and testing to ensure safe operation at B=1T. Jeremy also performed analysis of data from the Thomson scattering diagnostic. Jeremy received his PhD in the Spring of 2010, and began work at the Oak Ridge National Lab.
Celine joined HSX as an undergraduate in 2020. She built a test stand for the diagnostic neutral beam and is now continuing research on it as a graduate student. She hopes to improve the neutralization fraction of the beam and see if changing it from a hydrogen beam to a helium beam will help with other diagnostic measurements.
Dimitri joined HSX in the fall of 2017, and is now currently working to find the resonant electric field needed to see a transition into a non-linear viscosity regime in plasma. Once he finds the field using a biasing electrode, he plans to measure the flows in the regime.
Biography Patrick earned a bachelor’s degree in mechanical engineering from the University of Alaska Anchorage in 2020. He began working at HSX in 2021 before beginning his master’s degree in electrical and computer engineering, which he completed in 2024. He worked on the analysis of mechanical loading of the support structure of HSX as well …
Biography Jerahmie’s primary research area was in RF heating and the design and fabrication of a quasi-optical launching system for the high-power electron cyclotron resonance heating microwaves – 2 gyrotrons, 100-200 kilowatts each, for 50 to 75 milliseconds. His research concentrated on measurement and modeling of power deposition and coupling to the electrons under ECH, …
Michael joined the HSX team in the summer of 2023 as a graduate student. He received his bachelor's degree in applied engineering physics at Cornell University, where he learned about and studied every branch of physics and math he could find, gravitating towards energy research and plasma physics. He now pursues that interest by working on diagnostic development on HSX, specifically surrounding the existing reflectometry diagnostic. In the near future, he hopes to introduce Doppler Backscattering Reflectometry to the device, giving an additional avenue of fluctuation and flow analysis to HSX.
Biography Carlos studied the the diagnostic neutral beam used in HSX for CHERS flow measurements which is intended for use in Motional Stark Effect determination of the plasma electric field.
John worked on the design, installation, and analysis of the magnetic diagnostics on the HSX stellarator in order to measure the the equilibrium plasma currents present during the plasma discharge. The pressure-driven Pfirsch-Schluter current is helical in nature because of lack of toroidal curvature in the QHS magnetic spectrum, and reduced by the high effective transform (3). The net toroidal current is predominantly bootstrap-driven. The bootstrap current is modeled by PENTA, and the time and spatial evolution is modeled by a diffusion equation that includes the 3-D nature of the plasma column. John received his PhD in 2011 and began work at the Princeton Plasma Physics Laboratory in Princeton, NJ.
Kassia joined the HSX lab as a graduate student in 2024. She earned her bachelor's degree in physics from Carthage College in Kenosha, WI. She now works on analyzing fluctuation data to identify magnetohydrodynamic activity on HSX. As a joint member with the Wright lab, she is also working to compare the experimental data with MHD simulation data from the M3D-C1 code.
Jacob joined the HSX lab as a graduate student in 2024. He earned a Bachelor's degree in Physics at Temple University in Philadelphia, PA. He previously interned at the W7-X in Greifswald, Germany for the summer of 2023, where he analyzed Gas Puff Imaging (GPI) data using computer vision machine learning techniques. Now he is working with Thea Energy for the summer of 2024 to run simulations for a Fusion Power Plant (FPP) reactor study.
Luquant Singh completed his PhD in the Electrical and Computer Engineering Department studying magnetic confinement fusion. His research focuses on turbulence measurements in HSX plasmas using a Correlation Electron Cyclotron Emission diagnostic. Luquant joined HSX as an undergraduate in 2017 and investigated improvements to modular coil designs for future stellarators. He received a bachelor's degree in Applied Math, Engineering and Physics from UW-Madison in 2020 before joining the lab as a graduate student.
Jason has studied edge flows and field structure with a Gundestrup probe, the monoenergetic approximation in neoclassical transport calculations, neoclassical viscosity with a bias probe, and calculations of neoclassical impurity transport at HSX. Jason's thesis compares turbulent transport in the quasi-helical symmetry and broken symmetry configurations of HSX in both experiment and simulation using the GENE code, power balance calculations, and reflectometry measurements. Jason received his PhD in 2021 and began work on an electron-positron tabletop optimized stellarator at the Max Planck Institute for Plasma Physics in Greifswald, Germany.
Laurie studied plasma fueling and the HSX neutral population. She used H-Alpha measurements and the DEGAS and DEGAS 2 neutral Monte-Carlo codes to study the 3D neutral particle density, radial particle flux, and impacts of various fueling scenarios in HSX. Her work also included looking at the particle and energy balance at limiters placed at the edge of the HSX plasmas. Laurie received her PhD in 2017.
Alex received his BSME from the University of Portland in 2009. He was a systems engineer in the thermal spray industry until 2014 when he joined the Putterman Research Group at UCLA, where he studied plasma physics and helped develop a system which demonstrated acoustically confined, microwave heated plasma. He joined HSX in 2017, where he received his MSEE. He is currently working on a major upgrade to the ECRH system on HSX. His research interests include stellarator transport, RF heating, and wall conditioning systems.
The primary area of Gavin's work centered on the design, construction and implementation of the second ECH quasi-optical power transmission system for delivering power from the second 28 GHz gyrotron to HSX. The mirror is manually steerable to permit off-axis power deposition control. His research included examination of the heat propagation from modulated ECH heating, as compared to the overall the overall thermal diffusivity - a measure of the profile stiffness or resiliency, especially as this relates to the axisymmetric tokamak devices. Gavin received his PhD in 2014 and has since begun work at the Heliotron-J stellarator in Kyoto, Japan.
Bob studied the interaction of turbulence and flows in HSX and the effects of quasi-symmetry on the determination of the radial electric field in a stellarator. This was mainly done by using multi-tipped Langmuir probes to measure the radial electric field, density and potential fluctuations in the plasma edge, and then comparing these measurements with neoclassical calculations. Bob received his PhD in 2014 and began work at the Oak Ridge National Laboratory Fusion Energy group, then joined the General Atomics Fusion Group/DIII-D Laboratory in San Diego, CA.