That's not the same thing though. Those experiments weren't a simple alpha-emitter source; they were a neutron source that finely combined an alpha source with

That's not the same thing though. Those experiments weren't a simple alpha-emitter source; they were a neutron source that finely combined an alpha source with a low-Z element (aluminum? [0]), which was deliberately combined with fissionable nuclear material, thorium, to test nuclear fission reactions (on a very small scale). It's technically accurate to describe that one as a nuclear experiment. [0] https://cen.acs.org/articles/82/i32/PITFALLS-SELF-GUIDED-SCIENCE.html https://cen.acs.org/articles/82/i32/PITFALLS-SELF-GUIDED-SCI...