What exactly was the demon core and what did it do?

Question

I’ve read the Wikipedia article and watched a couple videos I’m still a bit confused

In: 3

Answer 1

It was a sphere of plutonium. Nearly large enough to go critical, it was used in a number of experiments to understand criticality in a nuclear device. Because of the technology of the age, some of those experiments were conducted by scientists. In some of the experiments unexpected events caused huge releases of nuclear radiation and a number of scientists were killed.