CV

Education

Massachusetts Institute of Technology, Cambridge, MA (2020 - Present)
- Ph.D. in Applied Plasma Physics, Department of Nuclear Science and Engineering
- Provisional thesis title: Prediction and avoidance of the tokamak density limit via interpretable machine learning
- Advisors: Drs. Cristina Rea, Robert Granetz, and Earl Marmar
Carleton College, Northfield, MN (2015 - 2019)
- B.A. in Physics (Distinction), minor in Public Policy

Research experience

MIT Plasma Science and Fusion Center, Cambridge, MA (September 2020 - August 2025)

Advisors: Cristina Rea, Robert Granetz, and Earl Marmar

My thesis research combines a multimachine database study and real-time control experiments at DIII-D to both elucidate and control the tokamak density limit.

At the heart of the analysis is a multi-machine database I constructed including 150+ L-mode density limits (LDLs), 70+ H-mode density limits (HDLs), and 3,000+ non-disruptive shots from Alcator C-Mod, ASDEX-Upgrade, DIII-D, and TCV. I then created a machine learning pipeline that identified a novel scaling for the precursor to the LDL, ν_*,edgeβ^-0.4_T,edge. This scaling outperforms others (ex. Greenwald fraction, Giacomin-Ricci scaling) as an LDL warning metric (Maris et al., NF 2024)
I earned PhD runtime at DIII-D to test real-time feedback control on this metric as an LDL avoidance solution. This control scheme successfully avoided LDL disruptions in 16 of 17 shots across 4 run days
Additionally, I analyzed the impact of disruptions on the economics of tokamak power plants, finding that the long warming/cooling cycles of the magnets and cryostat make unscheduled maintenance extremely costly (Maris et al., FS&T 2024)
A future publication is planned on the topic of the HDL and LDL, including an expanded database with experiments from JET and the DIII-D negative triangularity campaign

Publications and preprints

Correlation of the L-mode density limit with edge collisionality

Maris, Andrew D., Cristina Rea, Alessandro Pau, Wenhui Hu, Bingjia Xiao, Robert Granetz, Earl Marmar, the EUROfusion Tokamak Exploitation team, the Alcator C-Mod team, the ASDEX Upgrade team, the DIII-D Team, the EAST Team, and the TCV team. "Correlation of the L-mode density limit with edge collisionality." Nuclear Fusion (2024).

The impact of disruptions on the economics of a tokamak power plant

Maris, Andrew D., Allen Wang, Cristina Rea, Robert Granetz, and Earl Marmar. "The impact of disruptions on the economics of a tokamak power plant." Fusion Science and Technology (2023).

Investigating Boosted Decision Trees as a Guide for Inertial Confinement Fusion Design

Maris, Andrew D., Shahab F. Khan, Michael M. Pokornik, J. Luc Peterson, Kelli D. Humbird, and Steven W. Haan. "Investigating boosted decision trees as a guide for inertial confinement fusion design." Physics of Plasmas 30, no. 4 (2023): 042713.

Chaos in the quantum Duffing oscillator in the semiclassical regime under parametrized dissipation

Maris, Andrew D., Bibek Pokharel, Sharan Ganjam Seshachallam, Moses ZR Misplon, and Arjendu K. Pattanayak. "Chaos in the quantum Duffing oscillator in the semiclassical regime under parametrized dissipation." Physical Review E 104, no. 2 (2021).