Welcome! I am a Postdoctoral Associate at MIT’s Plasma Science and Fusion Center.
I received my PhD in Physics from MIT in June 2019.

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I am stationed full-time at the Joint European Torus (JET) tokamak located at the Culham Centre for Fusion Energy outside of Oxford, England. There, I maintain and operate the Alfvén Eigenmode Active Diagnostic, a collaborative effort among the MIT PSFC, CCFE, EPFL Swiss Plasma Center, and EUROfusion organization.

My primary research interests include
(i) the interaction of energetic particles (like DT fusion products) with magnetohydrodynamic waves called Alfvén Eigenmodes, and
(ii) 
the generation and evolution of relativistic “runaway” electrons in plasmas.

More broadly, I am interested in the physics – and prediction – of plasma disruptions, as well as the high magnetic field path toward future compact fusion devices.

 

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Research

My research interests include the physics of…
  • Alfvén eigenmode stability and energetic particle drive
  • Relativistic particles in plasmas – “runaway” electrons in tokamaks
  • Tokamak plasma disruptions – prediction, avoidance, mitigation, and impact
  • High magnetic field, compact fusion devices – concepts and diagnostics
  • Transformation optics and optical black holes

Alfvén Eigenmodes

The aim of my postdoc work is to measure stable Alfvén waves in tokamak plasmas before they are driven unstable by energetic plasma particles. To understand the motivation for this, let’s take a step back. In a magnetized plasma, magnetic field lines can support waves much like strings on a guitar. The pitch (frequency) of a guitar string decreases as its mass and length increase; the Alfvén frequency also decreases with the local plasma mass density. Because a guitar string is tied down at both ends, it can only support certain wavelengths (modes); the periodicity of a tokamak also only allows certain Alfvén eigenmodes (AEs). When you continuously strum a guitar, you provide energy to produce sound waves; analogously, energetic plasma particles (such as DT fusion products) can drive AEs.

But a guitar can’t play itself. In order to know which note a guitar string sounds, you must pluck it. In a similar way, we sweep our antenna frequency up and down (see the triangular waveform below) and try to resonantly excite AEs before they are destabilized (see the squiggles below). By “plucking” AEs in a variety of plasmas, we investigate their different driving and damping mechanisms. This is important because future fusion devices will produce many energetic alpha particles, which could drive AEs and potentially lead to degraded fusion performance. We are excited to see how our diagnostic performs in the upcoming DT experimental campaign of the JET tokamak.

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Runaway Electrons

My PhD thesis work focused on the physics of “runaway” electrons (REs) in tokamak plasmas. Interestingly, in a plasma, the probability of one particle colliding with another decreases as the particle’s speed increases. This means that, given a strong enough electric field in a plasma, a fast electron can overcome friction and “run away” to relativistic energies! While REs are neat plasma phenomena, they can also impact the wall of the plasma chamber and cause serious damage. The ultimate goal of this field of research is to understand enough about RE evolution to avoid (or mitigate) them in future fusion devices.

We generated REs in the Alcator C-Mod tokamak, which has a strong enough magnetic field for REs to emit visible synchrotron radiation. In close collaboration with the Plasma Theory group at the Chalmers University of Technology, I have studied how synchrotron spectra can indicate RE energieshow synchrotron images – like those shown below – can give insight into RE spatial and temporal dynamics, and how polarized synchrotron emission can probe the RE pitch angle distribution and current profile. I am currently leading the study of polarized synchrotron radiation on the JET tokamak.

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Tokamak Plasma Disruptions

Fusion-grade tokamak plasmas can have temperatures over 100 million Kelvin and carry currents over 1 million Amps! Therefore, they carry a lot of thermal and magnetic energy. Confining a donut-shaped plasma in a “magnetic bottle” can sometimes lead the plasma wriggling out of control and expelling its energy over milliseconds; this is called a plasma disruption. For future power-generating tokamaks, disruptions need to be predicted in advance and avoided – or their effects mitigated if avoidance is impossible.

To better understand the physics of disruptions, I have studied radiation asymmetries from mitigation of “healthy” and “sick” C-Mod plasmas, measured profiles of “halo” current as disrupting plasmas touch the vacuum vessel wall, and built databases for new machine learning applications to disruption prediction algorithms. Most recently, I used the statistical methods of survival analysis to make time-to-disruption predictions from output signals of a Random Forest disruption predictor.

(Runaway electrons – mentioned above – can also be generated during disruptions. See the impact of runaways with the vacuum vessel wall in the figure below.)

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High Field, Compact Fusion

A future fusion power plant will have to confine a plasma with a high enough pressure for a long enough time in order to produce net energy, i.e. more power output (from fusion reactions) than input (to run the device). In the past, the main focus of the fusion community was to make the device really big – more plasma means more power. However, big machines are costly. Recently, advancements in high temperature superconducting (HTS) magnets allow another path: compact (cheaper) devices with high magnetic field strengths, strong enough to balance high plasma pressure. This was the inspiration for the conceptual ARC pilot plant, as well as MIT’s newest venture, the net-energy SPARC tokamak, in collaboration with Commonwealth Fusion Systems.

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During my time at MIT, I got to work on – and inside! – the Alcator C-Mod tokamak. With the highest magnetic field strength of a tokamak, C-Mod broke the world record for stored plasma pressure on its last day of operation, 30 September 2016. Since then, I have helped update the ARC design – see the rendering – to include a novel divertor design and robust heat exhaust management system. In addition, I have explored the feasibility of neutron diagnostics for a high-field, compact, SPARC-like device.

 

Transformation Optics for Black Holes

The mathematical existence of black holes is one of the most amazing consequences of Einstein’s general theory of relativity. Astronomical evidence suggests that there are many super massive objects in our universe, sitting at the centers of galaxies and colliding to produce gravitational waves; these are very likely black holes. However, we will not likely have the chance to visit one in our lifetimes. A field of research called transformation optics aims to study black holes in the lab by tailoring optical media to have black-hole-like properties.

My good friend Andrew Turner and I submitted two short pieces to Harvard’s Black Hole Initiative essay competition. Andrew’s brainchild, “Black Holes, Entropy, and the Arrow of Time,” won fourth place! Check out this article in the magazine Nautilus and Elon Musk’s tweet about it. And my hope of “Building a better black hole demonstration” led to our newfound interest in and exploration of optical black holes.

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Recently, Andrew and I calculated the dielectric permittivity and permeability tensors which exactly reproduce the Kerr–Newman metric of a spinning, charged black hole. In addition, we determined the profile of scalar refractive index which can reproduce the trajectory of light all the way to the event horizon – see the simulation at right – of most KN black holes. Such an optical black hole could even be constructed with materials like glass, plastic, and water! 

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Publications + Presentations

Publications

first author publications

RA Tinguely and AP Turner. Optical analogues to the Kerr–Newman black hole. Submission in progress (2019) | arXiv:1909.05256

RA Tinguely, KJ Montes, C Rea, R Sweeney, and RS Granetz. An application of survival analysis to disruption prediction via Random Forests. Plasma Physics and Controlled Fusion 61 095009 (2019) | arXiv

RA Tinguely, M Hoppe, RS Granetz, RT Mumgaard, and S Scott. Experimental and synthetic measurements of polarized synchrotron emission from runaway electrons in Alcator C-Mod. Nuclear Fusion 59 096029 (2019) | arXiv

RA Tinguely, A Rosenthal, R Simpson, SB Ballinger, AJ Creely, S Frank, AQ Kuang, BL Linehan, W McCarthy, LM Milanese, KJ Montes, T Mouratidis, JF Picard, P Rodriguez-Fernandez, AJ Sandberg, F Sciortino, EA Tolman, M Zhou, BN Sorbom, ZS Hartwig, and AE White. Neutron diagnostics for the physics of a high-field, compact, Q ≥ 1 tokamak. Fusion Engineering and Design 143 212-225 (2019) | arXiv

RA Tinguely, RS Granetz, M Hoppe, and O Embréus. Spatiotemporal evolution of runaway electrons from synchrotron images in Alcator C-Mod. Plasma Physics and Controlled Fusion 60 124001 (2018) | arXiv

RA Tinguely, RS Granetz, M Hoppe, and O Embréus. Measurements of runaway electron synchrotron spectra at high magnetic fields in Alcator C-Mod. Nuclear Fusion 58 076019 (2018) | arXiv

RA Tinguely, RS Granetz, A Berg, AQ Kuang, D Brunner, and B LaBombard. High-resolution disruption halo current measurements using Langmuir probes in Alcator C-Mod. Nuclear Fusion 58 016005 (2018) | arXiv

co-authored publications

KJ Montes, C Rea, RS Granetz, RA Tinguely, N Eidietis, OM Meneghini, DL Chen, B Shen, BJ Xiao, K Erickson, and MD Boyer. Machine learning for disruption warning on Alcator C-Mod, DIII-D, and EAST. Nuclear Fusion 59 096015 (2019)

C Rea, KJ Montes, RS Granetz, RA Tinguely, and K Erickson. A real-time machine learning-based disruption predictor on DIII-D. Nuclear Fusion 59 096016 (2019)

ML Reinke, S Scott, RS Granetz, JW Hughes, SG Baek, S Shiraiwa, RA Tinguely, S Wukitch, and the Alcator C-Mod Team. Avoidance of impurity-induced Current Quench using Lower Hybrid Current Drive. Nuclear Fusion 59 066003 (2019)

AQ Kuang, NM Cao, AJ Creely, CA Dennett, J Hecla, B LaBombard, RA Tinguely, EA Tolman, H Hoffman, M Major, J Ruiz Ruiz, D Brunner, P Grover, C Laughman, BN Sorbom, and DG Whyte. Conceptual design study for heat exhaust management in the ARC fusion pilot plant. Fusion Engineering and Design 137 221–242 (2018) | arXiv

C Rea, RS Granetz, K Montes, RA Tinguely, N Eidietis, JM Hanson, and B Sammuli.  Disruption prediction investigations using Machine Learning tools on DIII-D and Alcator C-Mod. Plasma Physics and Controlled Fusion 60 084004 (2018)

M Hoppe, O Embréus, RA Tinguely, RS Granetz, A Stahl, and T Fülöp. SOFT: A synthetic synchrotron diagnostic for runaway electrons. Nuclear Fusion 58 026032 (2018) | arXiv

D Shiraki, RS Granetz, N Commaux, LR Baylor, D Brunner, CM Cooper, NW Eidietis, EM Hollmann, AQ Kuang, CJ Lasnier, RA Moyer, C Paz-Soldan, R Raman, ML Reinke, and RA Tinguely. Disruption Mitigation in the Presence of Pre-existing MHD Instabilities. Proceedings of the 26th IAEA Fusion Energy Conference EX/P3-20 (2016)

letters and essays

​AP Turner and RA Tinguely. How Black Holes Nearly Ruined TimeNautilus (January 2019)

AP Turner and RA Tinguely. Black Holes, Entropy, and the Arrow of Time. Awarded 4th place in the Harvard Black Hole Initiative essay competition (2018)

RA Tinguely and AP Turner. Building a better black hole demonstration. Submitted to the Harvard Black Hole Initiative essay competition (2018)

J Boguski, M Brown, R Buttery, R Churchill, W Guttenfelder, G Hammett, J Hanson, D Hatch, C Hegna, M Knolker, X Liu, L Lodestro, R Majeski, R Pinsker, M Shafer, D Sutherland, RA Tinguely, E Tolman, and D Weisberg. Discussion Group 5 Summary of USMFRSD Workshop in Austin, TX. Submitted to The National Academy of Sciences regarding A Strategic Plan for US Burning Plasma (2018)

Presentations

2019

Plasma survival analysis: Estimating survival probabilities and expected lifetimes from binary classification and Random Forests | Invited talk | 24th Workshop on MHD Stability Control | October 2019

Runaway Electrons in SPARC | Talk | 61st Annual Meeting of the APS Division of Plasma Physics | October 2019

An analysis of synchrotron radiation from relativistic electrons in the Alcator C-Mod tokamak | Doctoral Thesis Defense | MIT PSFC | May 2019

Experimental and synthetic measurements of polarized synchrotron emission from runaway electrons in Alcator C-Mod | Talk | Runaway Electron Meeting | January 2019

2018

Synchrotron spectra, images, and polarization measurements from runaway electrons in Alcator C-Mod | Talk | 60th Annual Meeting of the APS Division of Plasma Physics | November 2018

Synchrotron spectra, images, and polarization measurements from runaway electrons in the Alcator C-Mod tokamak | Poster | 45th EPS Conference on Plasma Physics | July 2018

Using SOFT and CODE to study spatiotemporal dynamics of runaway electrons in Alcator C-Mod | Talk | Runaway Electron Meeting | June 2018

Spatiotemporal dynamics of runaway electrons in Alcator C-Mod | Talk | US Transport Task Force Workshop | May 2018

2017

Synchrotron emission in Alcator C-Mod: Spectra at three magnetic fields, visible camera images, and polarization data | Poster | 59th Annual Meeting of the APS Division of Plasma Physics | October 2017

Halo current measurements using Langmuir ‘rail’ probes in Alcator C-Mod | Talk | ITPA MHD Workshop | October 2017

Fusion Energy | Presentation at MEETConf | Middle East Entrepreneurs of Tomorrow | July/August 2017

Synchrotron emission in Alcator C-Mod: Spectra at three B-fields and visible camera images | Talk | Runaway Electron Meeting | June 2017

A first look at the spatial distribution of runaway electrons in Alcator C-Mod | Poster | 9th ITER International School | March 2017

2016

Analysis of runaway electron synchrotron emission in Alcator C-Mod | Talk | 58th Annual Meeting of the APS Division of Plasma Physics | November 2016

Analysis of runaway electron synchrotron emission in Alcator C-Mod | Talk | Runaway Electron Meeting | June 2016

2015

Analysis of runaway electron synchrotron radiation in Alcator C-Mod | Talk | 57th Annual Meeting of the APS Division of Plasma Physics | November 2015

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News

in the news

A new path to solving a longstanding fusion challenge | MIT News | 9 October 2018

Bridging the divide with technology | MIT News | 14 November 2017

Profile in From Graphene to Galaxies: Graduate Physics at MIT | pages 4-7 | March 2017

PSFC invites the public to “Ask Me Anything” | PSFC | 24 October 2016

High-intensity fusion | MIT News | 14 October 2016

Alex Tinguely: Working toward a fusion future | MIT News | 20 November 2015

outreach

Energy Night provides close-up look at MIT’s fusion future | PSFC | 31 October 2018

Connecting with students, teachers and research colleagues at APS-DPP | PSFC | 3 November 2017

Scientists work side-by-side with students at Bay View High School | WTMJ-TV Milwaukee | 24 October 2017

Connecting with kids at AAAS | PSFC | 22 February 2017

PSFC fusion outreach ignites in Spring | PSFC | 10 May 2016

PSFC Local Outreach Programs Follow Recent National Efforts | PSFC | 9 December 2015

blog posts

Addir: Where scientists talk religion | MIT Graduate Admissions | April 2018

My Life as a GRT/Two Time Scootah Hockey World Champion | MIT Graduate Admissions | March 2018

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About

I am originally from Fort Madison, Iowa, where I graduated from Holy Trinity Catholic High School in 2010. I received my BS in Physics and Mathematics from Iowa State University in 2014. During the summer of 2013, I participated in the Science Undergraduate Laboratory Internship at the Princeton Plasma Physics Laboratory. There, my interest grew in plasma physics and fusion energy research. That brought me to the MIT Plasma Science and Fusion Center, where I received my PhD in Plasma Physics from the MIT Department of Physics in 2019.

Now I am a postdoc at the MIT PSFC working on the JET tokamak, sited at the Culham Centre for Fusion Energy just outside of Oxford, UK.

Activities

I sing! Currently, I am singing with the OXFORD BACH CHOIR, one of the oldest choirs in Oxford. Watch my past concerts of Britten/Vaughan Williams with the MIT CHAMBER CHORUS (April 2018) and my favorite piece, Carmina Burana, with the MIT CONCERT CHOIR (May 2017). I have also had the distinct honors of singing with Jacob Collier in this Emmy-winning documentary (December 2016), as well as Beethoven’s 9th Symphony with the Handel+Haydn Society for its bicentennial celebration (July 2015).

As a GRADUATE RESIDENT TUTOR in Simmons Hall at MIT, I lived with and mentored over 300 MIT undergraduate students. I enjoyed every minute living in the Sponge – a porous building with its own song – and getting to know some amazingly-talented, smart, and quirky kids. Read more about my experience as a GRT and playing scootah hockey here.

During summer 2017, I taught introductory Python to 80+ Palestinian and Israeli high schoolers participating in the Middle East Entrepreneurs of Tomorrow (MEET) program.  Based in Jerusalem, we met with students 5.5 days a week with the aim of fostering a welcoming, collaborative learning environment. Read more about my MEET experience with PSFC lab-mates here.

Teaching

  • TA for 22.63 Engineering Principles for Fusion Reactors, taught by Prof Dennis Whyte | Fall 2018
  • Completed Kaufman Teaching Certificate Program | Spring 2018
  • TA/Grader for 8.624 Plasma Waves, taught by Prof Miklos Porkolab | Spring 2017
  • TA/Grader for 8.613J/22.611J Introduction to Plasma Physics, taught by Prof Anne White | Fall 2015

Education

MASSACHUSETTS INSTITUTE OF TECHNOLOGY, Cambridge, MA, USA – PhD in Physics, Department of Physics, Plasma Science and Fusion Center, June 2019

IOWA STATE UNIVERSITY, Ames, IA, USA – BS in Physics and Mathematics, summa cum laude and with Honors, May 2014

HOLY TRINITY CATHOLIC HIGH SCHOOL, Fort Madison, IA, USA – Valedictorian, May 2010

Honors and Awards

  • Massachusetts Institute of Technology Energy Initiative Fellow | 2014-present
  • Student Marshall/Convocation Speaker, College of Liberal Arts and Sciences, Iowa State University | 2014
  • Phi Beta Kappa, Zeta Chapter of Iowa, Ruth and Clayton Swenson Award in the Sciences | 2013
  • National Merit Scholarship | 2010