同时还需要足够多的、可裂变的原子核用于中子进行撞击，换句话说，需要一个临界质量。

There also need to be enough fissionable atoms about for the neutrons to bumpinto—in other words, a critical mass.

youdao

同时还需要足够多的、可裂变的原子核用于中子进行撞击，换句话说，需要一个临界质量。

There also need to be enough fissionable atoms about for the neutrons to bumpinto—in other words, a critical mass.

youdao