The upcoming Mu3e experiment will search for the charged lepton flavour violating decay of a muon at rest into three electrons. The maximal energy of the electrons is 53 MeV, hence a low material budget is a key performance requirement for the tracking detector. In this paper we summarize our approach to meet the requirement of about 0.1 % of a radiation length per pixel detector layer. This includes the choice of thinned active monolithic pixel sensors in HV-CMOS technology, ultra-thin flexible printed circuits, and helium gas cooling.
@article{arxiv.1610.02021,
title = {Ultra-low material pixel layers for the Mu3e experiment},
author = {N. Berger and S. Dittmeier and L. Henkelmann and A. Herkert and F. Meier Aeschbacher and Y. W. Ng and L. O. S. Noehte and A. Schöning and D. Wiedner},
journal= {arXiv preprint arXiv:1610.02021},
year = {2016}
}