  The IceCube Neutrino Observatory at the South Pole is a multi-component
particle detector consisting of the IceTop surface array and the deep in-ice
IceCube array. The foreseen enhancement of the surface instrumentation will
consist of plastic scintillator panels read out by silicon photomultipliers.
This additional detector component will calibrate the effect of snow
accumulation on the IceTop tanks, improve the measurement of cosmic rays, and
enhance the atmospheric background rejection for the high-energy astrophysical
neutrino detection. Two scintillator prototype stations were deployed at IceTop
in the austral summer of 2017/18 to test the detector design and have started
taking data. In order to understand the properties of the scintillator panel
response a detailed Geant4 simulation of a single detector, including the
photon propagation and simulated SiPM response, is being developed and
parameterized. We investigate the capabilities of the IceTop upgrade with an
optimized layout of the new detectors and the accuracy of the reconstruction.
We will present the details of the simulation and reconstruction studies for
the proposed IceTop enhancement and report the capabilities of the combined
installation.
