Lithiated Graphite in Fusion Reactors

Nuclear fusion powers the stars and could be used to supply clean energy on Earth. A nuclear fusion plant would produce ten times more energy than a conventional nuclear fission reactor.

Scientists have been investigating the "plasma-material interface", the region in a fusion reactor where the inner lining cones into contact with the extreme heat of the plasma. A major challenge in finding the right coatings to line fusion reactors is that the material changes due to extreme conditions inside the reactors where temperatures can reach millions of degrees.

One such lining material uses lithium which is applied to the inner graphite wall of the reactor and diffuses into the graphite creating an entirely new material called lithiated graphite.
During a fusion reaction, some of the deuterium fuel atoms strike the inner walls of the reactor and either "pumped", causing them to bind with the lithiated graphite, or returned to the core and recycled back to the plasma.
The intense thermal energy inside the reactor causes tiny micro- and nano- scale features to "self-organise" on the surface of the lithiated graphite under normal plasma-surface interaction conditions. The surface only continues pumping for a few seconds before being compromised by damage induced by the extreme internal conditions.

Reference:
Purdue University (2010, July 27). Promise for nuclear fusion test reactors, findings show. ScienceDaily. Retrieved July 28, 2010, from http://www.sciencedaily.com­ /releases/2010/07/100727142415.htm

Study Questions

1. Define nuclear fusion.
2. Write an equation to represent a nuclear fusion reaction that might take place in a sun.
   
3. Define nuclear fission.
4. Write an equation to represent the nuclear fission of uranium-235.
   
5. How are deuterium atoms similar to hydrogen atoms?
6. How are deuterium atoms different to hydrogen atoms?
7. Name another isotope of hydrogen and give its symbol.
8. Name two allotropes of carbon.
9. Discuss the ways in which the two allotropes are the same.
10. Discuss the ways in which the two allotropes are different.
    
11. Draw a structure for graphite.
12. Use the drawing above to describe how lithiated graphite might be formed.
13. Discuss how deuterium atoms in the fuel plasma could bind to lithiated graphite.