A new source of clean energy might one day emerge from research that shows how electrons behave under the extreme temperatures and densities found within planets and stars, according to work from the UK and the US.
Until now, there have only been approximate models of electron behavior when large numbers are interacting as is the case with "warm dense matter". Now, researchers from Imperial College London, Kiel University, and Los Alamos and the Lawrence Livermore National Laboratories in the USA have developed an accurate simulation in which they have much greater confidence. IC's Matthew Foulkes explains that with this new model it should be possible to model planetary interiors, solids under intense laser irradiation, laser-activated catalysts; and other warm dense systems. "This is the beginning of a new field of computational science," he suggests.
The rules of electron behavior on the large scale are relatively straightforward, we have tools that relate voltage, resistance, and current. However, at the quantum level, the rules are different. In some ways, electrons behave like particles in a gas and previous models have only been able to simulate an "electron gas" at very low temperatures. Unfortunately, many of the interesting places in the universe whether planetary interior or laser-blasted material, experience conditions. For instance, warm dense matter can be ten thousand times hotter than room temperature and a hundred times denser than everyday solids. Its existence and our insights into it could help in our efforts to create a nuclear fusion reactor.
The team has now achieved the first complete description of the thermodynamic properties of interacting electrons in an electron gas in a range of warm dense matter. [Groth et al., Phys Rev Lett (2017); DOI: 10.1103/PhysRevLett.119.135001] According to Kiel's Michael Bonitz: "These results are the first exact data in this area, and will take our understanding of matter at extreme temperatures to a new level." The accuracy of the new simulation is down to an unprecedented 0.3% error margin. Bonitz suggests that four decades worth of earlier models can now be reviewed to reveal whether our tentative confidence in any of those was warranted and whether they can be modified or improved to help build an even clear understanding of warm dense matter and the electron gas. The team reports that this first completely ab initio exchange-correlation free energy functional will allow them to quantify the accuracy and systematic errors of earlier approximate functionals.
David Bradley blogs at Sciencebase Science Blog and tweets @sciencebase, he is author of the popular science book "Deceived Wisdom".