  LumiCal will be the luminosity calorimeter for the proposed International
Large Detector of the International Linear Collider (ILC). The ILC physics
program requires the integrated luminosity to be measured with a relative
precision on the order of 10e-3, or 10e-4 when running in GigaZ mode.
Luminosity will be determined by counting Bhabha scattering events coincident
in the two calorimeter modules placed symmetrically on opposite sides of the
interaction point. To meet these goals, the energy resolution of the
calorimeter must be better than 1.5% at high energies. LumiCal has been
designed as a 30-layer sampling calorimeter with tungsten as the passive
material and silicon as the active material. Monte Carlo simulation using the
Geant4 software framework has been used to identify design elements which
adversely impact energy resolution and correct for them without loss of
statistics. BeamCal, covering polar angles smaller than LumiCal, will serve for
beam tuning, luminosity optimisation and high energy electron detection.
Secondly, prototypes of the sensors and electronics for both detectors have
been evaluated during beam tests, the results of which are also presented here.
