High-density plasma was produced by exploding lithium wires. At the average electron concentration obtained, 2.5 × ${10}^{17}$ ${\mathrm{cm}}^{-3\mathrm{}}$, the measured Stark profile of the $2p-5d$ line is shown to be almost identical to that calculated for the ${\mathrm{H}}_{\gamma }$ line of hydrogen at the same electron concentration. The transition from quadratic to linear Stark broadening is discussed.

• Received 29 May 1968

DOI:https://doi.org/10.1103/PhysRev.176.227