Fusion glossary
L
In 1955, British physicist John Lawson (1923-2008) demonstrated that the conditions for fusion rely on three vital parameters: temperature (T), density (n) and confinement time (τ). (Lawson's Criteria)
Present in minerals and salt in the Earth's crust, lithium is the lightest metal, with atomic number 3. ITER will test specific lithium-containing wall modules to "breed" tritium (see Tritium breeding). In effect, tritium can be produced within the tokamak when neutrons escaping the plasma interact with lithium contained in the blanket.
Low-level entryways into the ITER vacuum vessel. The 9 lower ports will provide access into the vessel for remote handling, diagnostics, heating, and vacuum systems.