Generation and Parametrization of Mean Plasma Radiative Properties Databases for Astrophysics and Nuclear Fusion Applications

In plasmas found in nuclear fusion energy and astrophysics, radiative properties play a pivotal role and they are needed in radiation hydrodynamic simulations of these plasmas. However, their calculation is a very complex problem involving very long computational times. One of the solutions is to perform parametrizations of the plasma radiative properties as a function of the plasma conditions which leads to considerable reductions in computational costs. In this work, we present models to generate and parametrize radiative properties databases as a function of plasma conditions which are valid for any plasma thermodynamic regime.

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From natural to artificial photosynthesis

Journal of The Royal Society Interface ◽

10.1098/rsif.2012.0984 ◽

2013 ◽

Vol 10 (81) ◽

pp. 20120984 ◽

Cited By ~ 178

Author(s):

James Barber ◽

Phong D. Tran

Keyword(s):

Solar Energy ◽

Large Scale ◽

Nuclear Fusion ◽

Fusion Energy ◽

High Energy ◽

Primary Energy ◽

Energy Resources ◽

High Energy Density ◽

Chemical Bonds ◽

Natural Photosynthesis

Demand for energy is projected to increase at least twofold by mid-century relative to the present global consumption because of predicted population and economic growth. This demand could be met, in principle, from fossil energy resources, particularly coal. However, the cumulative nature of carbon dioxide (CO 2 ) emissions demands that stabilizing the atmospheric CO 2 levels to just twice their pre-anthropogenic values by mid-century will be extremely challenging, requiring invention, development and deployment of schemes for carbon-neutral energy production on a scale commensurate with, or larger than, the entire present-day energy supply from all sources combined. Among renewable and exploitable energy resources, nuclear fusion energy or solar energy are by far the largest. However, in both cases, technological breakthroughs are required with nuclear fusion being very difficult, if not impossible on the scale required. On the other hand, 1 h of sunlight falling on our planet is equivalent to all the energy consumed by humans in an entire year. If solar energy is to be a major primary energy source, then it must be stored and despatched on demand to the end user. An especially attractive approach is to store solar energy in the form of chemical bonds as occurs in natural photosynthesis. However, a technology is needed which has a year-round average conversion efficiency significantly higher than currently available by natural photosynthesis so as to reduce land-area requirements and to be independent of food production. Therefore, the scientific challenge is to construct an ‘artificial leaf’ able to efficiently capture and convert solar energy and then store it in the form of chemical bonds of a high-energy density fuel such as hydrogen while at the same time producing oxygen from water. Realistically, the efficiency target for such a technology must be 10 per cent or better. Here, we review the molecular details of the energy capturing reactions of natural photosynthesis, particularly the water-splitting reaction of photosystem II and the hydrogen-generating reaction of hydrogenases. We then follow on to describe how these two reactions are being mimicked in physico-chemical-based catalytic or electrocatalytic systems with the challenge of creating a large-scale robust and efficient artificial leaf technology.

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