Revision with unchanged content. Highly accurate probing techniques aid in understanding complex atomic electron systems. Some examples of complex atomic electron systems include multi-electron atoms, molecules, and atomic electrons in external electric fields. The techniques of scaled-energy recurrence spectroscopy, a Fourier transform method, are used in this dissertation to study the dynamics of highly-excited two-electron atoms created in a static electric field. In other experiments discussed here, ultra-short pulses of terahertz radiation, so called half-cycle pulses, are used to ionize highly-excited Stark eigenstates, probing their electronic probability distributions in momentum space. Through these studies the characteristics of Stark states, ultra-short pulsed terahertz radiation, and the limitations and accuracy of these probing techniques are explored.