When a neutron hits an atomic nucleus, the nucleus can absorb the neutron and become unstable.

当一个中子轰击一个原子核的时候，这个核可能会俘获这个中子，从而变的极不稳定。

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This is the point when neutrons released during the break-up of an atomic nucleus are more likely to hit and shatter other nuclei (thus releasing further neutrons), than to escape to the outside world where they merely generate Cherenkov radiation and tear up any living tissue that they pass through.

ECONOMIST: All over in a flash