  The International Linear Collider (ILC) is a proposed electron-positron
collider with a center-of-mass energy of 500~GeV, and a peak luminosity of $2
\cdot 10^{34}~\mathrm{cm}^{-2}\mathrm{s}^{-1}$. The ILC will complement the
Large Hadron Collider, a proton-proton accelerator, and provide precision
measurements, which may help in solving some of the fundamental questions at
the frontier of scientific research, such as the origin of mass and the
possible existence of new principles of nature.
  The linear collider community has set a goal to achieve a precision of
$10^{-4}$ on the luminosity measurement at the ILC. This may be accomplished by
constructing a finely granulated calorimeter, which will measure Bhabha
scattering at small angles. The Bhabha cross-section is theoretically known to
great precision, yet the rate of Bhabha scattering events, which would be
measured by the luminosity detector, will be influenced by beam-beam effects,
and by the inherent energy spread of the collider. The electroweak radiative
effects can be calculated to high precision and partially checked with events
with final state photon radiation by distinguishing between the observable
energy deposits of electrons and of photons in the luminosity calorimeter,
using a clustering algorithm.
  In order to achieve the design goal, the geometrical parameters of the
calorimeter need to be reevaluated. This must be done in a generalized manner,
so as to facilitate future modifications, the need for which is foreseen, due
to expected changes in the detector concept.
  This work demonstrates that the clustering approach is viable, and that a
luminosity calorimeter may be designed to match the precision requirements on
the luminosity measurement.
