I got the question the other day whether or not there are other, BIGGER accelerators in the works. Thing is, right now talking about building another accelerator right after this multi-billion dollar one started taking data would probably be such bad PR that no one would attempt it. But, what is in the works (and has been for quite a bit) is a different kind of accelerator. Rather than just go bigger and bigger, the technology within the accelerator is likely to change. For example, the magnets might get even nuttier, or something like that. Another idea that I heard about a little while ago, and is still in the research stage is a tabletop accelerator (that article is a bit old, from 2004, but I think it gives a prrretty good intro). If this could work, there are many great advantages. For one thing, it would be smaller (obviously), but it would also, hopefully, be cheaper — cheap enough that most universities could acquire one. That would be great for research.
Here’s a slightly newer article (from 2009) that speaks about more current things going on with tabletop accelerators. Note: SLAC is the Stanford Linear Accelerator; a linear particle accelerator located at Stanford University . Also, they talk about the particle, a positron, a lot in the article. Briefly, it’s the antimatter counterpart to an electron (same exact properties of an electron except it is positively, rather than negatively, charged — and the positron and electron will annihilate each other if they meet). More information on positrons found here. More information on antimatter here. (Sometimes Wikipedia is my best friend.) And here’s a slightly higher level article on antimatter that gives some history as well.