Date: Saturday, May 10, 2014 - 10:30
Venue: Theoretical Physics, 1 Keble Road, Oxford OX1 3NP
The fourth installment of the Mornings of Theoretical Physics was devoted to the physics of plasma – the fourth state of matter, the fabric of much of the visible universe (from stars to galaxies to intergalactic space), the fuel of fusion reactors – and a relatively recent addition to the core activities of the Rudolf Peierls Centre for Theoretical Physics.
The focus was on the fundamental properties of plasma – what is it? how to make it? how to hold it in a laboratory device? why does it rattle its magnetic cage, seethes and boils and ever rushes to escape? – and on the practicalities of the world’s combined effort to design a fusion power plant.
Speakers
Prof Felix Parra Diaz
Plasma: what it is, how to make it and how to hold it
Video podcast Presentation (PDF)
Plasmas are ionized gases that generate and interact strongly with electromagnetic fields. Most of the visible universe is in the plasma state. This talk describes the properties of plasmas, explaining how they are created and how they can be held using strong electromagnetic fields. One of the most promising uses of plasmas confined by strong magnetic fields is fusion energy. The talk also explores the unintuitive responses of a plasma imbedded in strong magnetic fields to forces with the objective of explaining the different configurations developed for fusion energy.
Prof Alex Schekochihin
Turbulence: plasma unleashed
Video Podcast Presentation (PDF)
Plasma is a strongly nonlinear system, possessing many degrees of freedom. It tends to take advantage of them, and so is often found in a state of chaotic, multiscale motion --- turbulence. It is turbulence that quickly mixes hot and cold plasma in a fusion device, thus limiting our ability to keep it hot inside and cold on the outside ("confine" energy). This talk starts with an explanation of how this "turbulent transport" arises, proceeds to conclude that a good theoretical understanding of turbulence is required to keep it under control, and then broadens out to introduce the basic concepts of Kolmogorov's theory of turbulence --- a phenomenon that is universal across many different nonlinear systems, from intergalactic plasmas to tokamaks, from planetary atmospheres to water streams. This "last great problem of classical physics" makes for a worthwhile focus of attention both by blue-sky theorists and by pragmatic engineers.
Prof Steve Cowley
Plasma tamed, fusion power and the theoretical challenge
Video podcast Presentation (PDF)
After many years of trying we are now able to create significant fusion reactions in plasmas at the Culham Centre for Fusion Energy. The next step is to create a “burning plasma” where the plasma is kept hot by the fusion reactions themselves. A new experiment, ITER, is being constructed in France to reach this critical scientific goal. In this talk I discuss the theoretical work at Culham and Oxford that is projecting the performance of this device. Further work is needed to bring down the scale of future fusion reactors — this too is being pursued at Oxford.
Date: Saturday, May 10, 2014 - 10:30
