lithium6

Lithium‑6 is a stable isotope of lithium with a mass number of six, consisting of three protons and three neutrons. Its natural abundance in lithium metal is approximately 7.5 percent, whereas the more common lithium‑7 constitutes about 92.5 percent. The isotope is produced primarily through the nuclear fission of heavy elements such as uranium and plutonium, as well as by neutron capture on lithium‑7 followed by beta decay of the resulting beryllium‑7. Some non‑nuclear methods involve the reduction of lithium hexafluorophosphate in a hydrogen atmosphere, but these are less efficient.

Lithium‑6 distinguishes itself by its high neutron absorption cross‑section, making it a critical component in nuclear weapons and research reactors. In thermonuclear weapons, lithium‑6 is irradiated by a primary fission explosion, producing tritium via the reaction 6Li(n,α)3H. The resulting tritium then serves as fuel for the secondary stage of a fusion device, dramatically increasing explosive yield. Because of these applications, the production and distribution of lithium‑6 are tightly controlled international regulations.

Beyond weapons, lithium‑6 has a niche role in scientific research. In neutron-generating experiments, the reaction 6Li(d,n)7Be provides a source of neutrons with precise energy spectra, useful for studies in nuclear physics and materials science. The isotope is also employed in certain types of trapping experiments that require lithium atoms with specific magnetic sub-levels.

In terms of safety, lithium‑6 behaves chemically like other lithium isotopes. It is highly reactive with water, forming lithium hydroxide and hydrogen gas, and it must be stored under inert atmospheres to prevent oxidation. Environmental concerns surrounding lithium mining and isotope enrichment are addressed through stringent regulatory frameworks in most producing countries.