U-235

I I have studied nuclear physics for 12 years. I know what im talking about. I just want to know how many other ways are possible from the traditional methods such as mercury.

Do you have any ideas?

We all know david hahn did it. Why cant we? ( safely of course!) To be honest all im bothered about is creating a neutron gun ( one that produces neutrons effectively and efficiently) im not looking to build the reactor its self i just want the neutron gun for studying affects of radiation and neutrons on plant cells etc. I do know about the basic lead block method but is there anything better? Any help?