遅発 ちはつ中性 ちゅうせい じゃなかったです
chihatsu chūseikojanakattadesu

Noun
Desu Copula

The polite, past negative form of 遅発中性子

1. Wasn't a delayed neutron.; Wasn't a late neutron.

Past/Perfective
Negative
Polite
Casual Register
Physics