In the baseline design of the International Linear Collider (ILC) an
undulator-based source is foreseen for the positron source in order to match
the physics requirements. The baseline parameters are optimized for the ILC at
sqrt(s)=500 GeV, that means an electron drive beam of 250 GeV. Precision
measurements in the Higgs sector, however, require measurements at sqrt(s)=250
GeV, i.e. running with the electron drive beam only at 125 GeV, which imposes a
challenge for achieving a high yield. Therefore the baseline undulator
parameters have to be optimized as much as possible within their technical
performances. In this bachelor thesis we therefore present a theoretical study
on the radiation spectra of a helical undulator, based on the equation for the
radiated synchrotron energy spectral density per solid angle per electron in
the relativistic, far-field and point-like charge approximation. From this
starting point the following undulator properties are examined: the deposited
power in the undulator vessel, which can disrupt the functionality of the
undulator magnets, the protective property of a mask on this disturbances and
the number of positrons produced by the synchrotron radiation in a Ti6Al4V
target. Those quantities were evaluated for various values for parameters as
undulator period, undulator length and magnetic flux in order to find optimal
baseline parameter sets for sqrt(s)=250 GeV.Comment: 15 pages, Talk presented at the International Workshop on Future
Linear Colliders (LCWS2018), Arlington, Texas, 22-26 October 201