EFFECTS OF DYNAMIC ION SHIELDING ON STARK BROADENING OF SPECTRAL LINES

Correlations among the charged particles in a plasma cause a modification of the Holtzmark distribution for the Stark broadening of spectral lines. Due to incomplete ion-ion shielding, the contribution to the electric microfield at a radiating atom, produced by a given ion, depends upon the state of motion of that ion. With the inclusion of this effect, a line shape is obtained which is similar to the shape obtained without this effect, except that it corresponds to a different plasma temperature. Thus if the electron and ion temperatures are the same, and if the Stark line shape is used to determine the plasma temperature, it is demonstrated that the inclusion of dynamic shielding effects will improve the temperature measurement by about 50 per cent. Corrections are obtained as a function of the electron-ion temperature ratio. © 1969.