  Due to their very fast signal rise time in the order of 1 ns,
Silicon-Photomultipliers have become of increasing interest for many
experiments that require very good timing resolution. With the prospect of an
application in medical imaging techniques like a Compton Camera or TOF-PET, a
coincident detection of Cherenkov photons from electrons in the MeV range in
PMMA has been performed. A 4x4 SiPM-array was used for this purpose and a
timing resolution of 242 ps has been achieved. A spatial sensitivity for an
electron source location could be shown using accumulated coincident light
signals. Obtained results are in good agreement with theoretical calculations
taking fundamental detector and set-up properties into account. These
measurements constitute an important step towards the feasibility of a
successful electron detection in a Compton Camera.

Instrumentation and Detectors