Looking for High Voltage Projects

I know a few things about high voltage electronics, and I've built and electric chair before with a microwave transformer, but I'm looking for something new to build. I've been exploring tesla coils and stuff, but I want to build something a little more obscure?

I want to fuse the atom at some point. 

Does anyone know any circuits to recommend?

Obviously anything would be built and opperated with the upmost of safety in mind.