Plasma detachment from a divertor target is defined as the state in wh
ich large gradients in total plasma pressure (static plus dynamic) are
observed parallel to the magnetic field with consequent reductions in
the plasma power and ion fluxes to the limiting surfaces. The origins
of this concept and the first experiments in a linear divertor simula
tor are described. Experimental evidence for this phenomenon from the
JET, JT60-U, DIII-D, Alcator C-Mod. and ASDEX-U tokamaks is reviewed a
long with recent advances in the theory and modelling of detached plas
mas applicable to current experiments. Plasma detachment from limiters
was first reported by TFTR in 1985, shortly followed by DITE and TEXT
OR. This phenomenon occurs in low power discharges near the density li
mit and is characterised by a shrinking of the layer where most of the
ionisation occurs away from the limiter. The physics, phenomenology a
nd relevance to fusion of detachment from limiters and diverters are c
ontrasted.