Speaker
Dirk Wiedner
(Physikalisches Institut der Universitaet Heidelberg)
Description
The Mu3e experiment searches for charged lepton flavor violation in the rare decay μ→eee. In order to reach a sensitivity of better than 10⁻¹⁶, more than 10⁹ muon decays per second have to be observed over a running time of one year. Precise determination of particle momentum, vertex position and time are necessary for background suppression. These requirements can be met by combining an ultra-lightweight tracker based on High-Voltage Monolithic Active Pixel Sensors (HVMAPS) with a timing system which consists of a scintillating fiber detector and a tile hodoscope. As the momentum of particles from muon decay is below 53 MeV/c, the silicon pixel tracker resolution is dominated by multiple Coulomb scattering. This leads to extreme requirements for the material budget of the tracking detector of below 0.1% of a radiation length per layer. Even though the target power consumption of the HVMAPS detector is as low as 150 mW/cm², the detector cooling must be very efficient and at the same time avoid adding material inside the active tracking volume. In this presentation the ultra-lightweight support structure and the gaseous helium cooling system for the thin silicon pixel tracker will be discussed.
Primary author
Dirk Wiedner
(Physikalisches Institut der Universitaet Heidelberg)
