Computational Methods in Modeling Fusion Plasmas

Fusion provides an attractive potential alternative to using fossil fuels for energy. Fusion requires vastly less fuel resources than does current non-renewable energy processes (virtually a 100% reduction in the required mass of fuel needed). The fuel sources needed (mainly deuterium and lithium) are also highly abundant on the Earth and fusion generates minimal waste products. One of the biggest obstacles to practical fusion energy is how to contain the reactants long enough for energy output to significantly exceed energy input. The equations governing plasma dynamics and confinement are highly nonlinear and do not admit simple analytic solutions in realistic situations. To obtain predictions of various plasma confinement scenarios, it is often necessary to turn to other means, such as computational modeling, to simulate the relevant plasma dynamics. Evaluating the effectiveness and reliability of the computational methods used for simulation then becomes extremely important, especially when subsequently using your code to predict new physics to the scientific community. In this work, we present an effort to analyze the effectiveness of one of the computational techniques used in the NIMROD code, which code Eric Held (USU) and others in the scientific community have helped to develop. This method involves resolving something called the Grad-Shafranov equation, which governs the potential plasma equilibria that can exist in tokamak plasmas. Here we evaluate the effectiveness of the method and discuss the potential implications resulting from this analysis

Consideration for UNOLS treatment of ORVs as Public Vessels

This document reviews the legal standards providing differential treatment of “public vessel” under federal regulations, including regulatory definitions of that term. In addition, it reviews language in key international legal instruments that provide similar special treatment for selected vessels owned by governments. This document is a supplement to Status of the U.S. Academic Research Fleet as Public Vessels under U.S. and International Law, which discusses the application of these and other legal authorities relevant to a determination of whether U.S. academic research fleet vessels are public vessels. The authorities presented here are separated by issuing agency (for regulatory citations). International authorities are presented separately. This document is to be used for research purposes only and is not legal advice