noun
neptunium series
A radioactive decay series starting with neptunium-237 and ending with thallium-205. Used in nuclear physics and radiochemistry.
ネプツニウム系列は、ネプツニウム237から始まる崩壊系列です。
The neptunium series is a decay series that begins with neptunium-237.
From English 'neptunium' (named after the planet Neptune) + 系列 (series).