A technique to generate self-consistent one-dimensional current sheets is described. Groups of monoenergetic protons were followed in a modified Harris magnetic field. The field parameters were adjusted to model a magnetotail region in which ion orbits cannot be described by the guiding center equations. This sample current sheet is characterized by resonant quasi-adiabatic orbits. The magnetic moment of a quasi-adiabatic ion which is injected from outside a current sheet changes substantially during the orbit but returns to almost its initial value by the time the ion leaves. The resonant nature of the interaction is associated with a strong energy dependence. Several ion and electron groups were combined to produce a plasma sheet in which the charged particles carry the currents needed to generate the magnetic field in which the orbits were traced. An electric field also is required to maintain charge neutrality. Three distinct orbit types, one involving untrapped ions and two composed of trapped ions, were identified. Each class of ions carried a qualitatively different current distribution. Contributions from all three groups are needed in order to generate a typical quiet-time self-consistent current sheet. Distribution functions were evaluated so that the expected count rates and several fluid parameters could be plotted. Limitations associated with the use of a one-dimensional model also were investigated. It was found that the model can provide a good physical picture of an important component of the cross-tail current. However, we concluded that one-dimensional models cannot adequately describe any region of the magnetotail in which the principal current sheet is separated from the plasma sheet boundary layer by a nearly isotropic outer portion of the central plasma sheet. ¿ American Geophysical Union 1993