The S-DALINAC is the in-house electron accelerator of the Institute of Nuclear Physics (IKP) at the TU Darmstadt. It is fed by two sources, a thermal source and one for polarized electrons, SPIn. SPIn produces polarized electrons with an energy of 100 keV. This is to be raised to 200 keV. In addition to the necessary modifications to the source, this is also important for the Mott polarimeter, which is used to measure the polarization of the electrons before they are fed into the actual accelerator. The polarimeter takes advantage of the asymmetric scattering that polarized electrons exhibit when scattered by charged particles. The fraction of electrons scattered at a given angle provides information about the direction of electron polarization. The angle at which this parity violation is greatest contains an energy dependence.

In this work, we check whether the counting rate of electrons is still sufficient after switching from SPIn to 200 keV at the detector of the polarimeter, which covers the scattering angle of 120°.

In addition, there are two other energies whose count rate will be investigated. The source of the test stand Photo-CATCH produces polarized electrons with 60 keV, for a cryogenic test source 30 keV electron energy is provided.