The operation of TPCs is steadily pushed to cope with higher rates.
This forces to consider the influence of space charge which is produced
in the ionisation of the drift gas as well as by ions possibly flowing back
from the amplification region.
The influence of the gas choice as well as a comparison between conventional
multi-wire proportional chambers and multi-pattern gas detectors will be
At the example of the ALICE TPC upgrade to a GEM based read-out system
the impact of space charge on the space-point reconstruction will be shown.
Additionally, the correction methods developed to minimize the impact on the
distortions will be discussed.