The fusion reaction triggered by the lasers within the tiny pellet of deuterium and tritium emits trillions of stray neutrons.

In a fusion reaction, we put deuterium and tritium together and get them very hot.

The objects, which are bigger than planets but smaller than stars, are unable to sustain the kind of nuclear fusion reaction that powers the sun.

This hydrogen-to-helium fusion reaction releases energy that balances the inward gravitational pressure and the star becomes stable for millions of years.

But first the target chamber needed to be equipped with shields to block neutrons that a fusion reaction would produce.