Thursday, May 10, 2007, 11am - 12pm, MDEA

Compact magnetic confinement for fusion energy

Setthivoine You

Tokyo University

Abstract

Because of a considerable amount of energy released per unit mass, fusion reactions have the potential to supply plentiful electricity on Earth and enable rapid human spaceflight throughout the Solar System. The current focus of fusion research is in terrestrial electrical production, where large gains are paramount. The large tokamak device spearheads the fusion research program and is now on the threshold of achieving reactor conditions.  In parallel, an "innovative confinement concepts" research program investigates fusion confinement schemes which may present cheaper and less massive alternatives to the tokamak.

In this talk I will present an introduction to the spheromak which presents some of the benefits of the tokamak while promising significant mass and cost savings. The important question of sustaining the configuration is directly related to the actual formation dynamics. The traditional formation model, called magnetic relaxation, is composed of a sequence of static states. Experimental results show the actual dynamics of magnetic relaxation. Beginning with a vacuum magnetic field and finishing with a toroid configuration, the results reveal a strong interaction between magnetic topology and plasma fluid flows.

These fluid flows play a significant role in generalizing the conventional model of magnetic relaxation. Understanding and controlling the fluid flows in addition to the magnetic topology is key to achieving new stable compact-toroid fusion confinement schemes. While such schemes may not necessarily compete today with the tokamak for terrestrial electrical power, they do present attractive solutions to fusion-based space propulsion.