NSE - Nuclear Science & Engineering at MIT


Zachary Hartwig

Zachary Hartwig

Robert N. Noyce Career Development Professor


Plasma Science and Fusion Center
CSTAR: Center for Science and Technology with Accelerators and Radiation


Zachary (Zach) Hartwig is the Robert N. Noyce Career Development Professor at MIT and an Associate Professor in the Department of Nuclear Science and Engineering (NSE) with a co-appointment at the MIT Plasma Science and Fusion Center (PSFC). He has worked primarily in the areas of large-scale applied superconductivity, magnet fusion device design, and plasma-material interactions with additional activities in nuclear security, radiation detector development, Monte Carlo particle transport simulation, and accelerator science and engineering. His active research focuses primarily on the development of high-field superconducting magnet technologies for fusion energy and accelerated irradiation methods for fusion materials using ion beams. He was the Principal Investigator and Project Head of the SPARC Toroidal Field Model Coil Project, a successful 3-year effort from 2018 to 2021 to design, build, and test the first large-scale, high-field, fusion-relevant high temperature superconductor magnet. He is a co-founder of Commonwealth Fusion Systems (CFS), a private company commercializing fusion energy. He oversees the NSE PhD qualification exam process, is a member of the MIT Radiation Protection Committee and Gender Equity Committee, and serves as an MIT First-Year Advisor. He received his PhD from MIT NSE in 2013 for developing a new generation of particle accelerator-based diagnostics to study plasma-material interactions in fusion devices and received his B.A. in Physics from Boston University in 2005. Hartwig won the 2022 Excellence in Fusion Engineering Award given by the Fusion Power Associates for his leadership in development of high magnetic field superconducting magnet technology.In 2024 he received the Committed to Caring award that celebrates MIT faculty members who have served as exceptional mentors to graduate students.


Intermediate energy proton irradiation of materials

Proton beams between 10 and 30 MeV offer a rapid, high fidelity approach to quantifying the evolution of engineering material properties in response to fusion-relevant radiation conditions. The proton energy provides the capability to tune the material response to match the application of interest while the uniform irradiation depth of protons in this energy range is several hundred microns or more, enabling bulk irradiation of macroscopic samples suitable for direct engineering property characterization such as tensile testing. Other advantages include high dose rates for rapid testing, low residual activation to simplify post-irradiation experiments, transmutation to produce bulk helium or radiation-induced precipitates.

High-field superconducting magnet technology

Recent advances in the performance and industrial production of high-temperature superconductors — particularly Rare Earth Barium Copper Oxide, or ReBCO— are enabling a new generation of large-scale superconducting magnets producing magnetic fields well in excess of 20 tesla for applications such as fusion energy, particle accelerators, and other industrial applications. Active research in this area is focused on demonstrating 50 to 100 kA class HTS conductors for large-scale magnets, qualifying novel quench detection technologies, developing defect-tolerant HTS conductors and magnets, quantifying progress evolution under irradiation, and building and testing the 20 tesla, 10 ton SPARC Toroidal Field Model Coil.


Recent Publications

  1. S.J. Jepeal, L. Snead, Z.S. Hartwig. Accelerated, high fidelity testing of fusion and fission reactor materials: opportunities and limitations of intermediate-energy proton irradiation, Materials and Design 200 (2021) 109445.
  2. S.J. Jepeal, ..., Z.S. Hartwig. An accelerator facility for intermediate energy proton irradiation and testing of nuclear materials, Nucl. Instr. and Meth. B 489 (2021) 41.
  3. Z.S. Hartwig et al. VIPER: An industrially mature high-current high temperature superconductor cable, Sup. Sci. and Techn. 33 (2020) 11LT01
  4. E. Salazar, ..., Z.S. Hartwig, High fidelity demonstration of fiber optic quench detection techniques for high temperature superconductor magnets, Sup. Sci. and Techn, 34 (2021) 035027.
  5. A. Molodyk, ..., Z.S. Hartwig,..., Development and large volume production of extremely high current density Y Ba 2 Cu 3 O 7 superconducting wires for fusion. Scientific Reports (2021) 11:2084.
  6. N. Strickland, ..., Z.S. Hartwig, ..., Extended-performance “SuperCurrent” cryogen-free transport critical- current measurement system, Accepted Manuscript in IEEE Trans. App. Supercon, 2021. https://doi.org/10.1109/TASC.2021.3060355
  7. M. Pham, L.A. Kesler, K.B. Woller, Z.S. Hartwig. Gamma Ray Production Cross Sections of Proton Bombardment of Fluorine for Light Element Analysis and Depth Profiling, 499 (2021) 118


Active Teaching (2021–2022)

  • 22.033: Nuclear Systems Design Project
  • 22.061: Fusion Energy

Past Teaching

  • 22.011: Hands on Introduction to Nuclear Science And Engineering
  • 22.814: Nuclear Weapons and Nuclear Security