On December 10th, 2021 we lost our respected colleague and leader of the DeNuSa project, Jaakko Härkönen.
Jaakko was a brilliant semiconductor physicist, always bursting with enthusiasm and ideas to develop novel and advanced radiation detectors for a multitude of applications. Since 2001, Jaakko was an active participant in the CERN CMS community, especially in the instrumentation of semiconductor Tracker. He was also one of the first members of CERN RD50 collaboration for the development of radiation hard semiconductor detectors.
In the 1990’s, Jaakko did pioneering work in Finland with semiconductor solar cells. He was a devoted teacher and mentor. Many generations of engineers and physicists achieved their M.Sc. and doctoral degrees under his skillful supervision. Jaakko was chosen by the European Commission’s ERA Chair Project to aid in the establishment of a Particle Detectors Laboratory for Croatia. Under his leadership, the PaRaDeSEC project was successfully completed and the Detector Laboratory is fully commissioned and operational at the Ruđer Bošković Institute in Zagreb. His legacy lives through his innovative work on detectors for nuclear safety in the DeNuSa-project.
We are thankful that we had the privilege to have worked with him. Jaakko was truly one of the kind.