Fusor.net’s fusioneers list has three levels. Scroungers are just starting out, gathering components and/or assembling parts. Plasma Club membership requires evidence of plasma production. Neutron Club applicants must provide rock-solid proof of fusion in the form of images and a full data disclosure regarding setup, conditions, and neutron-detection systems. “Many of the people who get the idea to build a fusion reactor have that long-shot sci-fi edge,” Willis says, but the technical challenges quickly weed out those who aren’t serious about mastering nuclear theory and engineering. “You can’t fake your way into the Neutron Club,” says Willis.