  A minority relativistic electron component can arise in both laboratory and
naturally-occurring plasmas. In the presence of high-atomic-number ion species,
the ion charge state distribution at low bulk electron temperature can be
dominated by relativistic electrons, even though their density is orders of
magnitude lower. This is due to the relativistic enhancement of the collisional
excitation and ionization cross sections. The resulting charge state effect can
dramatically impact the radiative power loss rate and the related Bethe
stopping power of relativistic electrons in a dilute plasma.
