Noun
English Wikipedia has an article on:Isotopes of lithiumWikipedia
lithium-6 (uncountable)
(physics) A stable isotope 3Li, having three protons and three neutrons, that makes up about 7% of natural lithium; it is used in the nuclear industry.
I also was producing, working on other materials for the hydrogen bomb. They call it lithium-6 and tritium. I was working on these and the only use for lithium-6 is the hydrogen bomb. Mordechai Vanunu
After slowing, neutrons may then be absorbed with an isotope that has high affinity for slow neutrons without causing secondary capture radiation, such as lithium-6. Source: Internet
The neutrons released from the fission of the sparkplug split lithium-6 into tritium plus helium-4 and lithium-7 into helium-4 plus tritium plus one neutron. Source: Internet