Completed-Theses.md

@@ -2,6 +2,11 @@
 
 ### PhD
 
+* 
+*Exploring Silicon Photomultipliers for the Upgrade of the Pierre Auger Observatory*
+(Johannes Schumacher, September 2018, 3a)
+[[pdf](https://git.rwth-aachen.de/tbretz/research/raw/master/Theses/PhD/Johannes Schumacher.pdf)]
+
 * 
 *Data acquisiton for a SiPM based muon detector* 
 (Lukas Middendorf, March 2018, 3a)