eli5 – How did scientists bombard uranium with neutrons?

Question

In 1938, how did the scientists bombard uranium with neutrons ( what device did they set up ), and how did they know they split the uranium atom?

I know I am just one of a million asking nuclear physics questions after the release of Oppenheimer, but I am just curious

In: 107

Answer 1

In the specific 1938 experiment they used a mixture of radium and beryllium. Radium emits alpha particles and beryllium emits neutrons when bombarded with alpha particles.
Nowadays they use what is called neutron spallation sources (there are many great explanations of this process on the internet)

They understood Uranium was split as it was the only way to explain that they found a bunch of lighter atoms in the sample that weren’t there before.