  The subject of space charge in ionization detectors is reviewed, showing how
the observations and the formalism used to describe the effects have evolved,
starting with applications to calorimeters and reaching recent, large-size time
projection chambers. General scaling laws, and different ways to present and
model the effects are presented. The relation between space-charge effects and
the boundary conditions imposed on the side faces of the detector are
discussed, together with a design solution that mitigates part of the effects.
The implications of the relative size of drift length and transverse detector
size are illustrated. Calibration methods are briefly discussed.
