I am an undergraduate about to enter my third year of university. I am interested in all of the following fields: plasma physics/fusion research, accelerator physics, fission reactor R&D, and low-energy nuclear physics. I plan to obtain a PhD in one of these and am mainly considering options at US government labs and private companies, though I would also consider a career in an English-speaking European country. I am generally interested in helping produce experiments/machines capable of performing advanced physics and/or power generation. Here are a few specific questions: 1. If ITER does not go smoothly is it likely that plasma physics R&D will become obsolete/not supported by the government? 2. I have heard that specialists in all of these fields (barring low-energy nuclear physics) are in high demand... is that likely to still be the case in 10-20 years? 3. Not that pay is my primary concern, but it seems to me that fission reactor engineers are the highest-paid in this set of fields. Is that correct? 4. Does anyone have information/metrics about how competitive it is to succeed in these fields? My intuition is that far less people are going into these fields than, say, condensed matter... I Next I have a few questions about what work is specifically involved in these fields. All of them involve building such complex and expensive equipment that they must be tested by simulations. Excluding designing things in CAD, do simulations account for the majority of work in designing a nuclear reactor/tokamak/accelerator (etc.)? Are the people who do simulations the ones who end up making the final say on the design of such experiments?