The science behind fusion power

This is the second post of our series on nuclear fusion power.

The science behind fusion is not simple. The treatment I give it during these posts is necessarily brief, and more descriptive than quantitative in nature. It generally takes years of studying to gain a firm grasp of the concepts employed in the study of nuclear fusion.

However, an interested person can gain a good working knowledge of many of these concepts much more quickly. It is certainly possible to gain an intuitive grasp of most physics concepts without having gone through years of formal education in the field. There are many science resources for the general public which are aimed at creating this sort of understanding. I also hope that this series of posts is a significant aid to curious people without a formal background in physics.

If you want to dig deeper into the science that underlies these concepts, I recommend the following resources as starting points. I am assuming of course that the reader is able and willing to track down a lot of their own information for the mathematical and physical foundations of these concepts if they are necessary for understanding. What I have listed here are just the general things that stick out at me as being fundamentally necessary to understand nuclear fusion reasonably well.

Electromagnetism

This is the most important of the four fundamental forces for considerations of plasma containment. The coulomb interaction is the basic fact that presents a barrier to fusion processes, where the positively charged nuclei will repel one another.

The best general book on the subject of electromagnetism is certainly Griffiths Introduction to Electrodynamics. This book is regarded by many as the best textbook in all of physics.

If you want web resources that cover the topics of Griffiths: you can learn Vector Analysis in several places around the Internet, similarly with electrostatics, Laplace’s equation, method of images, polarization, magnetostatics, and so on.

However, I haven’t found any online resource that comes even close to challenging the quality of Griffiths. If you want to save yourself a lot of online detective work and confusion on these topics, buy Griffiths Introduction to Electrodynamics.

To understand the basics of fusion techniques, you need to understand coulomb interaction and magnetostatics. Knowledge of electrodynamics and Faraday’s law would be very helpful for understanding the tokamak.

Nuclear Physics

Hyperphysics has a good introduction to nuclear physics. I find their work to be generally of high quality. Wikipedia also has many nice articles on the subject. One that I liked at a glance was the one on the atomic nucleus.

Another easy introduction can be found at Think Quest, where they have a page on nuclear physics. Note that the titles of each section are clickable, and take you to a page detailing that topic.

In school I used the textbook Introductory Nuclear Physics by Kenneth Krane. Don’t let the word ‘introduction’ fool you. This is an 864 page book that goes into exquisite detail about not only what we know about the atomic nucleus, but how we know it. Krane approached this from an experimentalist point of view, which I appreciate.  Some other books will present simply what we know, not how we know it.  He shows how every major nuclear discovery since the time of Ernest Rutherford took place, and what we learned from it. In short, I was very impressed with this book.

Thermodynamics

Earlier in this piece I mentioned the Carnot Engine and the second law of thermodynamics. These two concepts are very important, but they are only a tiny portion of the areas of thermodynamics that are directly relevant to Nuclear Fusion.

I have yet to read a good textbook on the subject of thermodynamics, but I imagine there are some. The most read book I could find on the subject at Amazon was actually Thermodynamics by Enrico Fermi. Apparently this is an incredible textbook. It assumes that the reader understand calculus (up to at least partial differentiation). For those that don’t know, Enrico Fermi was a Nobel Prize winner in physics. He was incredibly influential in the development of physics as we know it today, as well as the nuclear fission program. The term fermion bears his name. It is a term that is used more often in the subject areas of particle physics and high-energy physics.

For a lower-level introduction, I liked the look of this piece on thermodynamics at Think Quest (note that there is a menu on the right with the laws of thermodynamics). A more technical approach can be found on NASA’s Thermodynamics page.

Plasma Physics

Plasma physics depends on exceedingly good knowledge of electromagnetism and thermodynamics. Also, it is good to know some statistical mechanics as well.

Plasma physics is complicated and difficult. Gaining an intuitive feel for these concepts may be much harder than with the fields listed above. I certainly found this to be so. I recommend getting at least a good solid primer in the above subjects before even attempting to dig into plasma physics in depth.

As far as online resources go, I found a very nice looking site by I. H. Hutchinson. It actually looks like there is an entire textbook worth of knowledge there available for free. On the first page it says:

A solid undergraduate background in classical physics, electromagnetic theory including Maxwell’s equations, and mathematical familiarity with partial differential equations and complex analysis are prerequisites.

If you are looking for a physical textbook on plasma physics, I am afraid that there are none that I can recommend from my own experience. However, there is a textbook that I found recently that seems to be very well regarded. It is Introduction to plasma physics and controlled fusion by Francis F. Chen.

Good luck!

This concludes my brief overview of the areas of physics knowledge that are necessary for understanding fusion power at a relatively deep level. I encourage people to pursue their interests in these areas. The web is an incredible information resource, even on subjects that seem as inscrutable as complex physics.

I will also make a general plug for the Google Scholar search engine. It has helped me immensely over the years. I like that it now displays pdf (or other document type) links to the right of the results. This means I can quickly scan to see which results have free versions available online. I find that this is an excellent way to quickly access quality scholarship on almost any subject.

I bid you all good luck and happy learning!

For further reading, you may be interested in our introduction to fusion power, or our follow-up post on tools for understanding nuclear fusion.