Evan Davis

  • Academic Institution: Massachusetts Institute of Technology
  • Program Year: 4
  • Practicum(s):
    Lawrence Livermore National Laboratory (2011)
  • Degree(s):
    B.S. Applied Mathematics, University of California at Riverside, 2010; B.S. Physics, University of California at Riverside, 2010
  • Field of Study: Plasma Physics and Fusion
  • Academic Advisor: Miklos Porkolab

Summary of Research:

With the increasing global appetite for high-level energy, the disconcerting projections of conventional energy reserves, and the desire to minimize anthropologically induced climate change, society is under unprecedented pressure to develop clean, sustainable supplies of energy. In light of these challenges, nuclear fusion is a potential game-changer. During a fusion reaction, light nuclei combine to form a heavier nucleus and release a large amount of energy via Einstein’s E=mc². Fusion is inherently safe, does not directly produce radioactive waste, and is resistant to nuclear proliferation. The abundance of relevant fusion fuel isotopes on earth would provide a virtually inexhaustible supply of clean energy.

Currently, the leading candidate for a magnetic fusion reactor is the tokamak, a doughnut shaped vacuum device that uses powerful magnetic fields (~2-3 T) to confine a hot (~100 million degrees C) ionized gas referred to as plasma. Energy confinement and potential fusion gain in tokamaks is believed to be strongly controlled by plasma parameters in the edge region, or so-called plasma pedestal, just inside the last closed magnetic flux surface. Thus, a comprehensive, first-principles model of edge turbulence is a topic of much contemporary research. Development of such a model requires an effective coupling between experiment and theory.

My research involves experimental characterization of plasma turbulence in the Alcator C-Mod and DIII-D tokamaks to help validate the Boundary Plasma Turbulence (BOUT++) code, which simulates nonlinear fluid boundary turbulence in realistic tokamak geometry. Experimental measurements in both tokamaks are made with Phase Contrast Imaging (PCI), an interferometric technique that measures line-integrated electron density fluctuations at high temporal and spatial bandwidth (10 kHz < f < 10 MHz, 1.5/cm < k < 30/cm). Ongoing upgrades to the DIII-D PCI system will extend the minimum detectable k to 0/cm, allowing the detection of multiscale density fluctuations important for model validation. The improved understanding of plasma turbulence from this work will aid the magnetic fusion effort and may also have important applications to turbulent processes occurring in inertial fusion and astrophysical phenomena.

Publications:

PUBLICATIONS:
B. LaBombard, T. Golfinopoulos, J. L. Terry, D. Brunner, E. M. Davis, et al. "New insights on boundary plasma turbulence and the Quasi-Coherent Mode in Alcator C-Mod using a Mirror Langmuir Probe", Phys. Plasmas, to be submitted

J. W. Hughes, P. B. Snyder, J. R. Walk, E. M. Davis, A. Diallo, et al., "Pedestal structure and stability in H-mode and I-mode: a comparative study on Alcator C-Mod", Nucl. Fusion, 53 043016, 2013.

R. J. Groebner et al. "Improved understanding of physics processes in pedestal structure, leading to improved predictive capability for ITER", 24th IAEA Fusion Energy Conf. San Diego, CA, EX/11-4, 2012.

E. M. Davis, J. B. Parker, and Y. Raitses, “High-Speed Imaging Analysis of Discharge Oscillations in the Cylindrical Hall Thruster”, DOE Journal of Undergraduate Research, Vol. X, 2010.


PRESENTATIONS:
E. M. Davis, M. Porkolab, J. W. Hughes, B. LaBombard, P. B. Snyder, and X. Q. Xu, "Stability of Alcator C-Mod's EDA H-mode with resistive, diamagnetic, and electron parallel pressure gradient effects", 55th Annual Meeting of the APS Division of Plasma Physics, Denver, CO, TM9.00003, Nov. 11-15, 2013.

E. M. Davis, M. Porkolab, J. W. Hughes, B. LaBombard, J. C. Rost, P. B. Snyder, and X. Q. Xu, "Opportunities for synergy between experiments and BOUT++ modeling on Alcator C-Mod and DIII-D", BOUT++ 2013 Workshop, Livermore, CA, Sept. 3-6, 2013.

E. M. Davis, M. Porkolab, J. W. Hughes, P. B. Snyder, and X. Q. Xu, "Mapping Alcator C-Mod's EDA H-Mode Stability Boundaries with BOUT++", US-EU Joint Transport Task Force Workshop, Santa Rosa, CA, Apr. 9-12, 2013.

E. M. Davis, M. Porkolab, J. W. Hughes, and X. Q. Xu, “BOUT++ Simulations of Edge Turbulence in the Alcator C-Mod Tokamak”, BOUT++ 2011 Workshop, Livermore, CA, Sept. 14-16, 2011.

E. M. Davis and M. Barth, “Real-World Hybrid Electric Vehicle Energy Efficiency Analysis”, UCR’s 2007 Undergraduate Research Symposium, Riverside CA, May 2007.


POSTERS:
E. M. Davis, M. Porkolab, J. W. Hughes, P. B. Snyder, and X. Q. Xu, "Simulations of Stability and Turbulence in Tokamak Fusion Reactors", 7th Annual DOE NNSA SSGF Program Review, Santa Fe, NM, June 25-27, 2013.

E. M. Davis, M. Porkolab, J. W. Hughes, P. B. Snyder, and X. Q. Xu, "Mapping Alcator C-Mod's EDA H-Mode Stability Boundaries with BOUT++", 54th Annual Meeting of the APS Division of Plasma Physics, Providence, RI, JP8 86, Oct. 29 - Nov. 2, 2012.

E. M. Davis, M. Porkolab, J. W. Hughes, and X. Q. Xu, "BOUT++ Simulations of Edge Turbulence in Alcator C-Mod's EDA H-Mode", 6th Annual DOE NNSA SSGF Conference, Arlington, VA, July 26-27, 2012.

E. M. Davis, M. Porkolab, J. W. Hughes, and X. Q. Xu, "BOUT++ Simulations of Edge Turbulence in Alcator C-Mod's EDA H-Mode", US Transport Task Force Workshop, Annapolis, MD, Edge P11, Apr. 10-13, 2012.

E. M. Davis, M. Porkolab, P. Ennever, N. Tsujii, J. W. Hughes, and X. Q. Xu, “Experimental and Theoretical Studies of Edge Turbulence in the Alcator C-Mod Tokamak”, 53rd Annual Meeting of the APS Division of Plasma Physics, Salt Lake City, UT, UP9 8, Nov. 14-18, 2011.

E. M. Davis, M. Porkolab, P. Ennever, N. Tsujii, J. W. Hughes, and X. Q. Xu, “Experimental and Theoretical Studies of Edge Turbulence in the Alcator C-Mod Tokamak”, 5th Annual DOE NNSA SSGF Conference, Arlington, VA, July 21-22, 2011.

E. M. Davis, J. B. Parker, and Y. Raitses, “High-Speed Imaging Analysis of Discharge Oscillations in the Cylindrical Hall Thruster”, 176th American Association for the Advancement of Science (AAAS) Annual Meeting, San Diego, CA, Feb. 2010.

E. M. Davis, J. B. Parker, and Y. Raitses, “High-Speed Imaging Analysis of Discharge Oscillations in the Cylindrical Hall Thruster”, 51st Annual Meeting of the APS Division of Plasma Physics, Atlanta, GA, JP8 64, Nov. 2009.

Awards:

DOE NNSA SSGF Fellow (2010-Present)

DOE NNSA SSGF Essay Contest Winner (2013)

MIT PSFC Student Outreach Award (2013)

Graduated Summa Cum Laude with a B.S. in Physics and a B.S. in Applied Mathematics (2010)

Outstanding Academic Achievement Award in the College of Natural and Agricultural Sciences (2010, given to one graduating student in each of UCR's colleges)

Robert L. Wild Family Undergraduate Scholarship Award for Outstanding Bachelor of Science Graduate (2010)

DOE SULI appointment, Princeton Plasma Physics Laboratory, 2009

Phi Beta Kappa Honor Society (inducted in April 2009; only top 2% of UCR's Junior class is elected)

UCR Dean's Honors List (Quarterly Award: 2006, 2007, 2008, 2009, 2010)

UCR Chancellor's Honor Roll (Annual Award: 2006-2007, 2008-2009, 2009-2010)

UCR Honors Convocation Award Recipient (2007, 2008, 2009, 2010)

CRC Press Chemistry Achievement Award (Awarded to top 3 UCR General Chemistry Students) (2007)

Jim Guthrie Research Scholarship for outstanding undergraduate research conducted at UCR’s CE-CERT (2007)

Best in Group Presentation at UCR’s Undergraduate Research Symposium (2007)

UCR Regents Scholarship Award Recipient (2006-2010)