Research

The MFE-IM group specializes in delivering reliable, accurate, and validated predictions of core transport physics in magnetic confinement fusion devices. By harnessing the power of data science and machine learning, we develop cutting-edge simulation and optimization workflows, utilizing high-fidelity simulation frameworks established, verified and validated within the fusion energy community.

At MFE-IM, our primary focus lies in forecasting core kinetic profiles, fusion power, and reactor performance through the integration of multi-channel transport simulations and plasma heating, equilibrium, stability and radiation models. We actively contribute to the design of groundbreaking burning plasma experiments and fusion pilot plants. Collaborating with experimental groups worldwide, both from public and private sectors, we strive to deepen our understanding of magnetically confined plasmas and validate simulation workflows through participation in world-class fusion experiments.

Current Areas of Interest

The MFE-IM group is interested in developing and utilizing workflows for tokamak scenario modeling, with an emphasis on core turbulence and transport physics. We are building expertise in the following workflows to predict core plasmas:

We have contributed to the physics basis of the SPARC tokamak and we continue fruitful collaborations with Commonwealth Fusion Systems as they develop a robust experimental plan to achieve net plasma gain and burning plasmas in the SPARC tokamak. Members of MFE-IM also lead the SPARC Performance & Transport (P&T) group whose mission is to provide physics-based simulations of SPARC and ARC scenarios.

As a group, we are interested in the use of medium and high fidelity transport modeling directly during the design of burning plasma experiments and fusion pilot plants. We believe that to achieve fusion device solutions that are both feasible and economically attractive, we must utilize core transport physics models from the beginning of engineering design.

P. Rodriguez-Fernandez et al. Nucl. Fusion 62, 076036 (2022)

The confidence in the predictions of future fusion devices relies upon our capability to reliably simulate current experiments. In MFE-IM, we are interested in using high-fidelity transport simulations to simulate core plasmas in existing and past tokamaks (DIII-D, ASDEX Upgrade, Alcator C-Mod and JET) and compare them to diagnostic measurements of kinetic profiles, turbulence and inferred transport coefficients. Over the years we have built tools, workflows and metrics to help understand where and when transport models fail in describing the physics of the tokamak core.

While we are involved with numerous core transport validation exercises, the areas of special interest for MFE-IM are:

  • Multi-scale turbulence and isotope effect
    Even though small scale fluctuations are usually expected to have a small impact on transport in realistic tokamak core plasmas, in some special situations they (and their coupling to larger scales) might be necessary to reproduce experiment results. This is known as multi-scale or cross-scale turbulence effects and the simulations were pioneered by MFE-IM scientist N.T. Howard in the 2010s. Understanding in which situations multi-scale simulations are required remains an important area of research and of interest to the MFE-IM group, including whether or not they can contribute significantly to the so-called isotope effect observed experimentally in current day devices.

    N.T. Howard et al 2016 Nucl. Fusion 56 014004
  • Impurity transport
    While most validation exercises of the core of tokamaks are performed with respect to energy fluxes, impurity transport is gaining attention in the fusion community, as future burning plasmas and pilot plants will suffer from some level of impurity accumulation. This is especially damaging in the burning-plasma regime and with high-Z wall materials (as most devices are scoped). Understanding how heavy, non-hydrogenic (impurity) ions are transported and distributed in the plasma core is an important focus of the MFE-IM group.

    N.T. Howard et al Nucl. Fusion 61 (2021) 106002
  • Perturbative transport
    Static, power-balance transport validation studies can only consider single-point, standalone experimental data. Understanding how transport responds to perturbations around stationary conditions is key in revealing whether a transport simulation properly simulates the underlying physics mechanisms or if it matches transport levels fortuitously. In MFE-IM, we are interested in finding out ways to utilize perturbative transport tools (particularly, cold and heat pulses) to validate transport models.

    P. Rodriguez-Fernandez et al. Physics of Plasmas 26, 062503 (2019)
  • Multi-field, multi-channel validation
    Well-diagnosed tokamak plasmas, particularly those with turbulence measurements, provide an important opportunity to validate transport simulations. Cutting-edge measurements of core fluctuations such as those provided by the Correlation Electron Cyclotron Emission (CECE) diagnostic, can be compared directly to the behavior of nonlinear turbulence simulations. In our group, we collaborate with experimental teams that develop these diagnostics to carry out multi-field (e.g. kinetic profiles, fluctuations), multi-channel (e.g. electrons, ions, impurities) validation of core models.

    N.T. Howard et al. APS-DPP 2022

In MFE-IM we are interested in utilizing Bayesian Optimization (BO) techniques to solve complex problems in fusion energy and plasma physics. We developed the PORTALS tool to enable the interaction of standard BO workflows (particularly the BoTorch package) with fusion and plasma physics tools such as TGLF, TGYRO, CGYRO, FREEGS and others.

So far, we have applied BO to the following problems:

At MFE-IM we are especially interested in finding ways to incorporate physics understanding to aid in the optimization process and in the creation of reliable surrogate models that can accelerate the convergence of Bayesian and surrogate-based optimization workflows.

In MFE-IM we acknowledge that the direct use of full-physics models in scenario modeling tools is cumbersome and can be very computationally expensive. Consequently, an area of active research in MFE-IM is the development of machine-learning enhanced models (such as Neural Networks and Gaussian Processes) to reproduce the output of black-box type simulations of core transport and scenario modeling tools. We are currently working in developing models for impurity transport and energy fluxes specifically for the parameter space of the SPARC tokamak to be implemented in flight-simulators for scenario and control purposes.

Recent Research Products

  • Journal Publication
  • Conference Proceedings
  • Conference Contribution
  • Seminar
2024
  • Sherwood 2024, contributed poster
    P. Rodriguez-Fernandez, N. T. Howard, C. Holland and J. Candy, “Surrogate modeling as a pathway to enable high fidelity predictions of tokamak performance“, Sherwood Fusion Theory Conference, Missoula (MT), May 6-8 2024.
  • US-TTF 2024, contributed poster
    A. Saltzman, et al, “On the effect of empirical modeling core transport assumptions in tokamak design“, 33rd US Transport Task Force Workshop, Asheville (NC), April 9-12 2024.
  • US-TTF 2024, contributed poster
    V. Galvan, et al, “Developing a Neural Network Surrogate Model for Fast Integrated Modeling of SPARC“, 33rd US Transport Task Force Workshop, Asheville (NC), April 9-12 2024.
  • US-TTF 2024, contributed poster
    I. Marshall, et al, “Preliminary Analysis Towards Developing a Core to Edge Integrated Model of Impurity Transport“, 33rd US Transport Task Force Workshop, Asheville (NC), April 9-12 2024.
  • US-TTF 2024, contributed talk
    P. Rodriguez-Fernandez, N.T. Howard, A. Saltzman, L. Shoji, T. Body, D. Battaglia, J.W. Hughes, J. Candy, G.M. Staebler and A.J. Creely, “Predictions of Core Transport and Performance in SPARC First-Campaign Plasmas with Nonlinear CGYRO“, 33rd US Transport Task Force Workshop, Asheville (NC), April 9-12 2024.
  • US-TTF 2024, contributed talk
    M. Muraca, et al, “Sensitivity Study of SPARC Full-Field H-Mode with a Quasi-Linear Transport Model“, 33rd US Transport Task Force Workshop, Asheville (NC), April 9-12 2024.
  • US-TTF 2024, contributed poster
    J. Hall, et al, “Predictions of Pedestal Height and Integrated Modeling of Performance and Transport in ARC“, 33rd US Transport Task Force Workshop, Asheville (NC), April 9-12 2024.
  • US-TTF 2024, contributed poster
    R. Bielajew, et al, “Gyrokinetic modeling of negative triangularity plasmas in ASDEX Upgrade“, 33rd US Transport Task Force Workshop, Asheville (NC), April 9-12 2024.
  • US-TTF 2024, contributed poster
    N. Howard, et al, “Insights Into the Origin of Electron Density Peaking Obtained from Nonlinear Gyrokinetic Profile Predictions“, 33rd US Transport Task Force Workshop, Asheville (NC), April 9-12 2024.
  • ITPA TC 2024, invited talk
    A. Ho, J. Citrin, C. D. Challis, C. Bourdelle, F. J. Casson, J. Garcia, J. Hobirk, A. Kappatou, D. L. Keeling, D. B. King, F. Koechl, E. Lerche, C. F. Maggi, J. Mailloux, and JET Contributors, “Predictive JET current ramp-up modelling using QuaLiKiz neural network”, 32nd Transport and Confinement ITPA Topical Group Meeting, ITER Organization (France), Apr 16 – Apr 18 2024.
  • SMARTS 2024, contributed talk
    P. Rodriguez-Fernandez, “PORTALS: introduction, status and plans”, 1st SMARTS-FRONTIERS SciDAC Workshop, San Diego (CA), Feb 27 – 29 2024.
  • Worcester Polytechnic Institute, Physics Department
    R. Bielajew, “Magnetic confinement fusion: the confinement challenge and turbulence measurements”, Guest Seminar, Worcester (MA), February 28, 2024.
  • DigiLab
    A. Ho, “Fusion Week Webinar: Fusion and AI”, Expert panel seminar for Fusion Energy Week – U.S. Fusion Energy, online, May 9th 2024.
  • Richi Foundation
    P. Rodriguez-Fernandez, “The Promise of Fusion Energy at MIT”, Fireside chat for Richi Innovation Camp, Cambridge (MA), March 14th 2024.
  • Real Colegio Complutense, Harvard University
    J. Aguilera Toste, “Magnetic Confinement Fusion: integrated modeling techniques“, Made in UPM speaker series, Cambridge (MA), February 22nd 2024.
2023
  • N.T. Howard, P. Rodriguez-Fernandez, C. Holland, T. Odstrcil, B. Grierson, F. Sciortino, G. McKee, Z. Yan, T.L. Rhodes, G. Wang, A.E. White, J. Candy and C. Chrystal, “Performance and transport in ITER: Multi-channel validation in DIII-D ITER-like conditions and predictions of ITER burning plasmas via nonlinear gyrokinetic profile prediction”, Proceedings for the 29th IAEA Fusion Energy Conference (2023).
  • P. Rodriguez-Fernandez, N.T. Howard, A. Saltzman, S. Kantamneni, A.E. White, E. Delabie, B. Lomanowski, T.M. Biewer, J. Candy, C. Holland, M.F.F. Nave, J. Garcia, L. Lennholm and JET Contributors, “Core performance predictions with nonlinear gyrokinetics and implications to scope burning-plasma tokamaks”, Proceedings for the 29th IAEA Fusion Energy Conference (2023).
  • APS-DPP 2023, contributed talk
    A. Saltzman, P. Rodriguez-Fernandez, M. Muraca, R. Bielajew, N.T. Howard, A.E. White, G. Tardini, and the ASDEX Upgrade Team, “Validity of using heat pulse diffusivity as a proxy for incremental diffusivity in validation studies”, 65th Annual Meeting of the APS Division of Plasma Physics, Denver (CO), Oct 30 – Nov 3 2023.
  • APS-DPP 2023, contributed poster
    A. Saltzman, J. Ball, M. Calvo-Carrera, T. Evans, S. Mackie, S. Moroch, G. Rutherford, J. van de Lindt, T. Varnish and A. Velberg, “Altator: A new toroidal outreach device for the PSFC”, 65th Annual Meeting of the APS Division of Plasma Physics, Denver (CO), Oct 30 – Nov 3 2023.
  • APS-DPP 2023, contributed poster
    A.S. Tema Biwole, N.T. Howard, P. Rodriguez-Fernandez, T. Odstrcil, K.E. Thome, and F. Sciortino, “Impurity transport studies in DIII-D H-mode plasmas: Experiment and Turbulence Modeling”, 65th Annual Meeting of the APS Division of Plasma Physics, Denver (CO), Oct 30 – Nov 3 2023.
  • APS-DPP 2023, contributed poster
    M. Muraca, P. Rodriguez-Fernandez, N.T. Howard, A. Saltzman, and G. Tardini, “Flexible test of reduced transport models for SPARC scenarios in ASTRA”, 65th Annual Meeting of the APS Division of Plasma Physics, Denver (CO), Oct 30 – Nov 3 2023.
  • APS-DPP 2023, contributed talk
    N.T. Howard, P. Rodriguez-Fernandez, C.G. Holland, A.J. Creely, and J. Candy, “Predictions of Reactor Performance Utilizing Nonlinear Gyrokinetic Simulations: SPARC, ITER, and ARC-class reactors”, 65th Annual Meeting of the APS Division of Plasma Physics, Denver (CO), Oct 30 – Nov 3 2023.
  • APS-DPP 2023, invited talk
    P. Rodriguez-Fernandez, N.T. Howard, A. Saltzman, L. Shoji, J.W. Hughes, D.J. Battaglia, T.A. Body, A.J. Creely and J. Candy, “On the direct use of core non-linear gyrokinetic profile predictions for the planning of burning plasmas experiments”, 65th Annual Meeting of the APS Division of Plasma Physics, Denver (CO), Oct 30 – Nov 3 2023.
  • IAEA-FEC 2023, plenary talk
    N.T. Howard, P. Rodriguez-Fernandez, C. Holland, T. Odstrcil, B. Grierson, F. Sciortino, G. McKee, Z. Yan, G. Wang, T.L. Rhodes, J. Candy, S. Haskey, C. Chrystal, A. Bortolon and the DIII-D Team, “Performance and Transport in ITER: Multi-Channel Validation in DIII-D ITER-Like Conditions and Predictions of ITER Burning Plasmas Via Nonlinear Gyrokinetic Profile Prediction”, 29th IAEA Fusion Energy Conference, London (UK), Oct 16-21 2023
  • IAEA-FEC 2023, poster
    P. Rodriguez-Fernandez, N.T. Howard, E. Delabie, B. Lomanowski, S. Kantamneni, J. Candy, C. Holland and JET Contributors, “Core performance predictions with nonlinear gyrokinetics and implications to scope burning-plasma tokamaks”, 29th IAEA Fusion Energy Conference, London (UK), Oct 16-21 2023.
  • EPS 2023, invited talk
    P. Rodriguez-Fernandez, N.T. Howard, E. Delabie, B. Lomanowski, A. Saltzman, S. Kantamneni, J. Candy, C. Holland, M.F.F. Nave, T.M. Biewer, J. Garcia, M. Lennholm, A.E. White and JET Contributors, “Prediction of core kinetic profiles and burning plasma performance with high-fidelity gyrokinetic simulations in tokamaks“, 49th EPS Conference on Plasma Physics, Bordeaux (France), Jul 3-7 2023.
  • IAEA-FDPVA 2023, contributed talk
    P. Rodriguez-Fernandez, N.T. Howard, J. Candy and C. Holland, “Bayesian optimization techniques to accelerate burning-plasma and reactor simulations“, IAEA Technical Meeting on Fusion Data Processing, Validation and Analysis, Ghent (Belgium), June 12 – 15 2023.
  • US-TTF 2023, contributed poster
    A. Saltzman, P. Rodriguez-Fernandez, R. Bielajew, M. Muraca, N.T. Howard, A.E. White, and G. Tardini, “Exploring equivalence of heat pulse diffusivity and incremental diffusivity in multi-channel transport modeling simulations”, 32nd US Transport Task Force Workshop, Madison (WI), May 2-5 2023. (poster)
  • US-TTF 2023, plenary talk
    N.T. Howard et al., “Multi-Channel Validation in DIII-D ITER-Similar Shape Conditions and Prediction and Optimization of ITER Burning Plasmas via Nonlinear Gyrokinetic Profile Prediction“, 32nd US Transport Task Force Workshop, Madison (WI), May 2-5 2023.
  • US-TTF 2023, plenary talk
    P. Rodriguez-Fernandez, N.T. Howard, J. Candy and C. Holland, “Modeling of burning plasma performance in SPARC via first-principles core turbulence simulations“, 32nd US Transport Task Force Workshop, Madison (WI), May 2-5 2023.
  • ITPA TC 2023, invited talk
    N.T. Howard et al., “Prediction and Optimization of ITER Burning Plasmas via Surrogate Accelerated Nonlinear Gyrokinetic Profile Prediction“, ITPA Transport and Confinement, Madison (WI), April 25-58 2023.
  • ICDDPS 2023, contributed talk
    P. Rodriguez-Fernandez, N.T. Howard, S. Kantamneni, J. Candy and C. Holland, “Leveraging surrogate-based optimization to enable profile predictions with nonlinear turbulence codes“, 4th International Conference on Data Driven Plasma Science, Okinawa (Japan), Apr 16-21 2023.
  • Meta-AE 2023, invited talk
    P. Rodriguez-Fernandez, N.T. Howard and J. Candy, “Optimization techniques to accelerate the realization of fusion energy”, 2nd Meta Adaptive Experimentation Workshop, New York (NY), Apr 10-11 2023.
  • Massachusetts Institute of Technology, Nuclear Science and Engineering Department
    P. Rodriguez-Fernandez, “Predicting core performance in burning plasmas: from empirical models to nonlinear simulations”, Guest Speaker for course 22.016 on Seminar in Fusion and Plasma Physics, Cambridge (MA), December 13th 2023.
  • Princeton Plasma Physics Laboratory, Computational Sciences Department
    P. Rodriguez-Fernandez, “Enabling multi-channel profile predictions with nonlinear gyrokinetics via surrogate-based optimization techniques”, Computational Sciences Seminar at Princeton Plasma Physics Laboratory (PPPL), Princeton (NJ), September 28th 2023.
  • Institute for Theoretical Physics UAM-CSIC
    P. Rodriguez-Fernandez, “Fusion energy at MIT: from empirical to first-principles understanding of burning plasmas“, Plasma Physics Colloquium Speaker at Institute for Theoretical Physics (IFT UAM-CSIC), Madrid (Spain), June 26th 2023.
  • Polytechnic University of Madrid, School of Industrial Engineering
    P. Rodriguez-Fernandez, “Fusion Energy at MIT: Smaller, cheaper, faster”, Lecture for Nuclear Science and Technology graduate program and Erasmus-Mundus SARENA at ETSII-UPM, Madrid (Spain), June 6th 2023.
  • MIT Plasma Science and Fusion Center
    P. Rodriguez-Fernandez, “Enabling first-principles predictions of core performance in tokamaks with surrogate optimization techniques“, MIT Plasma Science and Fusion Center Seminar, Cambridge (MA), March 3rd 2023.
  • Columbia University, Applied Physics and Applied Mathematics
    P. Rodriguez-Fernandez, “Core transport and performance of burning plasmas in the SPARC tokamak“, Plasma Physics Colloquium, Applied Physics and Applied Mathematics department at Columbia University, New York (NY), February 17th 2023.
  • University of Seville, School of Physics
    P. Rodriguez-Fernandez, “Energía de fusión en el MIT: El camino de los campos magnéticos de alta intensidad y el tokamak SPARC“, Seminar for School of Physics at University of Sevilla, Sevilla (Spain), January 20th 2023.
  • Institute of Photonic Sciences
    P. Rodriguez-Fernandez, “The high-field path to fusion energy and the SPARC tokamak“, Colloquium Series at the Institute of Photonic Sciences (ICFO), Barcelona (Spain), January 13th 2023.
2022
  • HEPP 2022, contributed talk
    M. Muraca, et al., “Reduced transport models for a tokamak flight simulator“, International Helmholtz Graduate School for Plasma Physics (HEPP) Colloquium, Garching bei Muenchen, 18 Nov 2022.
  • APS-DPP 2022, contributed talk
    A. Saltzman, P. Rodriguez-Fernandez, R. Bielajew, N.T. Howard, A.E. White, G. Tardini, and the ASDEX Upgrade Team, “Study of the impact of ion temperature perturbations on the inferences of incremental electron thermal diffusivity”, 64th Annual Meeting of the APS Division of Plasma Physics, Spokane (WA), Oct 17-21 2022.
  • APS-DPP 2022, invited talk
    N. Howard, et al., “Multi-Z Impurity Transport in DIII-D ITER Similar Shape Plasmas: Experiment, Gyrokinetic Simulation, and Gyrokinetic Based, Flux-Matched Profile Predictions”, 64th Annual Meeting of the APS Division of Plasma Physics, Spokane (WA), Oct 17-21 2022.
  • APS-DPP 2022, contributed talk
    P. Rodriguez-Fernandez, N. Howard, J. Candy, A. Creely and the SPARC Performance & Transport Group, “First-principles performance prediction of burning plasmas with self-consistent kinetic profiles“, 64th Annual Meeting of the APS Division of Plasma Physics, Spokane (WA), Oct 17-21 2022.
  • Varenna/Lausanne 2022, contributed poster
    M. Muraca, et al., “Reduced transport models for a tokamak flight simulator“, Joint Varenna/Lausanne International Workshop, Varenna, 12-16 Sep 2022.
  • EPS 2022, contributed talk
    M. Muraca, et al., “Reduced transport models for a tokamak flight simulator“, 48th European Conference on Plasma Physics, Maastricht, Jun 27–Jul 01 2022.
  • US-TTF 2022, contributed poster
    A. Saltzman, P. Rodriguez-Fernandez, N.T. Howard, A.E. White, “Investigation of role of the ion channel in the experimental interpretation of incremental electron thermal diffusivity”, 31st US Transport Task Force Meeting (Joint EU/US), Santa Rosa (CA), Apr 5-8 2022.
  • US-TTF 2022, contributed talk
    P. Rodriguez-Fernandez, N. Howard and J. Candy, “Towards multi-channel profile predictions with full nonlinear gyrokinetic simulations in burning plasmas“, 31st US Transport Task Force Meeting (Joint EU/US), Santa Rosa (CA), Apr 5-8 2022.
  • SMuK 2022, contributed poster
    M. Muraca, et al., “Reduced transport models for a tokamak flight simulator“, DPG-Frühjahrstagung der Sektion Materie und Kosmos , Mainz, 21-25 Mar 03 2022.
  • Wesleyan University
    P. Rodriguez-Fernandez, “The high-field path to fusion energy and the SPARC tokamak“, Physics Colloquium at Wesleyan University, Middletown (CT), September 29th 2022.
  • Computational Physics School for Fusion Research
    P. Rodriguez-Fernandez, “Optimization projects for the advancement of fusion energy“, Computational Physics School for Fusion Research (CPS-FR), MIT, August 22nd 2022.
  • National Autonomous University of Mexico
    P. Rodriguez-Fernandez, “The high-field path to fusion energy and the SPARC tokamak“, Universidad Nacional Autónoma de México (ICF-UNAM), June 1st 2022.

Funding Sources

The MFE-IM group is funded via differences sources. We thank the US Department of Energy Fusion Energy Sciences program and Commonwealth Fusion Systems for sponsored research funds, the National Science Foundation and the Nuclear Science and Engineering department at MIT for providing doctoral fellowships to students in the group, and the Universidad Politécnica de Madrid for funding short-stay visiting students.

Active Collaborations

The work we do at MFE-IM could not be done without the support of our collaborators, particularly experimental teams at world-class facilities and theory teams that develop the high-performance simulations…

(Updates In Progress)