Plasma shifts of the He iiHαandPαlines

Shift measurements for the $H_{\alpha }$ (1640 Å) and $P_{\alpha }$ (4686 Å) hydrogenic ion lines of He i i have been done over an electron density range 2×${10}^{22}$ to 2×${10}^{23}$ ${\mathrm{m}}^{\mathrm{-}3}$ and for an electron temperature of 4 eV. The plasma was produced in a linear Z discharge. Systematic red shifts linear in density are observed. The experimental data are compared with combined theoretical estimates for electron-impact and ion quadrupole effects. The experimental results are in agreement with our earlier results for $P_{\alpha }$. .AE