By coincidence I'm currently reading The Boy Who Played with Fusion https://www.amazon.com/Boy-Who-Played-Fusion/dp/0544705025, which tells the amazing story of Taylor Wilson (https://en.wikipedia.org/wiki/Taylor_Wilson) who performed this feat when he was 14.

It's mind boggling what dedicated kids can achieve with parental backing and scientist mentors. In Wilson's case places like The Black Hole surplus store (https://www.roadsideamerica.com/story/18130) also greatly helped. Sadly such places are getting rarer.