text: The metallothermic reduction of anhydrous rare-earth fluorides to rare-earth metals is also referred to as the Ames process.
  The study of rare earths was also advanced during World War II:  Synthetic plutonium was believed to be rare-earth-like, it was assumed that knowledge of rare earths would assist in planning for and the study of transuranic elements; ion-exchange methods developed for actinide processing were forerunners to processing methods for rare-earth oxides; methods used for uranium were modified for plutonium, which were subsequently the basis for rare-earth metal preparation.