The ${\mathrm{H}}_{\mathrm{\beta }}$ line shifts were measured in dense ssT-shaped-tube plasmas for electron densities from 2.1×${10}^{17}$ to 7.8×${10}^{17}$ ${\mathrm{cm}}^{\mathrm{-}3}$ and temperatures between 19 000 and 35 000 K. Comparisons of these shifts with recent theories [H. R. Griem, Phys. Rev. A 28, 1596 (1983); 38, 2943 (1988)] that take the dynamical quadratic Stark effect for Δn=0 and n’=n+1 interactions and ion quadrupole effects into account are presented. Also, comparisons with some experimental results [H. L. Wiese, D. E. Kelleher, and D. R. Paquette, Phys. Rev. A 6, 1132 (1972)] were made. Our results are in agreement with an extrapolated experimental best fit to the experimental results of Wiese et al., but the measured shifts are larger than the theories predict.

• Received 19 November 1990

DOI:https://doi.org/10.1103/PhysRevA.43.6095