Woodruff School of Mechanical Engineering

NRE 8011/8012 and MP 6011/6012 Seminar

Nuclear & Radiological Engineering and Medical Physics Programs

Title:

Experimental Studies of Plasma-Material Interactions Relevant to Magnetically Confined Fusion Devices

Speaker:

Dr. David Donovan

Affiliation:

Univ of Tennessee-Knoxville

When:

Thursday, February 18, 2016 at 11:00:00 AM

Where:

Boggs Building, Room 3-47

Host:

Dr. Weston Stacey
weston.stacey@nre.gatech.edu
404-894-3714

Abstract

Magnetically confined fusion energy research has advanced dramatically in the last several decades with regard to the ability to sufficiently heat and confine a plasma to achieve operating conditions that can be extrapolated to a power producing fusion reactor. As fusion plasmas have become hotter and more sustained, the issue of plasma-material interactions (PMI) has been rising to the forefront as a critical concern that must be confronted before the eventual development of an efficient fusion power reactor. The challenge is to identify materials and operating configurations that maximize the lifetime of plasma-facing components (PFCs) and minimize the introduction of impurities into the plasma. This presentation will discuss several experimental PMI studies that have been conducted by researchers at Sandia National Laboratory (SNL) and the University of Tennessee-Knoxville (UTK) in the areas of boundary plasma physics, material characterization, and understanding of PFC damage mechanisms. This research includes experiments conducted on the DIII-D tokamak in San Diego, CA involving sheath power transmission studies and surface heat flux characterization, as well as at the Tritium Plasma Experiment (TPE) at Idaho National Laboratory (INL) studying high temperature plasma-driven permeation of deuterium and tritium in tungsten. Helium ion damage studies have been performed at SNL using a compact electron cyclotron resonance (ECR) source and an upgraded ion exposure stage is now available at UTK to continue this work. UTK researchers have also contributed to the operation and diagnosis of the high-flux linear plasma device, the Prototype Material Plasma Exposure eXperiment (Proto-MPEX), at Oak Ridge National Laboratory (ORNL). These projects encompass a broad range of research opportunities from small experiments to large tokamaks and demonstrate the value of forging strong collaborations between multiple institutions to more effectively advance fusion energy science towards the goal of building a fusion power reactor.


Biography

David Donovan is currently an assistant professor in the Nuclear Engineering Department at the University of Tennessee-Knoxville. He received his PhD in Nuclear Engineering from the University of Wisconsin-Madison in 2011 and his BS in Nuclear Engineering at the University of Illinois at Urbana-Champaign. His PhD work was in the area of Inertial Electrostatic Confinement (IEC) Fusion for the purpose of creating and utilizing small-scale neutron generating devices to detect explosives and other illicit materials. He was a post-doctoral research associate at Sandia National Laboratories/California in the Hydrogen and Metallurgy Sciences Department. His work at Sandia was in the area of plasma-surface interactions in magnetically confined fusion devices. He collaborated extensively with the DIII-D tokamak operated by General Atomics in San Diego, CA as well as with the Tritium Plasma Experiment located at Idaho National Laboratory. He developed expertise in grazing incidence x-ray diffraction and atomic force microscopy, and use of laboratory scale RF and microwave plasmas. His work since joining UTK includes plasma and heat flux diagnostic development and analysis with the Proto-MPEX experiment at ORNL, development of a low-flux He implantation stage for testing damage to fusion materials, and collaborations with research on medical isotope production. Dr. Donovan is also introducing a new series of undergraduate and graduate courses at UTK in the area of Nuclear Fusion Technology.