Lowering of Ionization Potentials in Plasmas

The average electrostatic potential near a nucleus immersed in a plasma is evaluated using a finitetemperature Thomas-Fermi model. The part of this potential directly attributable to the presence of the plasma is isolated and is used to evaluate the reduction in ionization potential for a wide range of parameters. A simple analytic solution, exhibiting Debye-Hiickel and ion-sphere limits, is also obtained and is used as an interpolatory device.