Power distribution for the Mu3e experiment

The Mu3e experiment aims to measure the charged flavour violating decay ${\mu }^{+}$$\to$$e^{-}{e}^{+}{e}^{+}$ with a single events sensitivity of 2$\cdot$10${}^{-15}$ in the first data taking phase. For this purpose, a DC muon beam of 10${}^8$${\mu }^{+}$/s will be stopped inside a Si pixel tracker constructed from High-Voltage Monolithic Active Pixel Sensors (HV-MAPS), complemented with timing detectors. The entire experiments resides within a superconducting solenoid proving a homogeneous magnetic field of 1 T. All 3136 detector ASICs combined need about 5 kW of power at 1.8 V. In addition, the serial data from the individual sensors is processed by front-end FPGAs before being send off via optical links to the outside, adding another 2.7 kW of power needed at voltages of 1.1 to 3.3 V. This requires a power distribution system which works inside the magnetic field and takes into account to the tight space constrains of the experiment. DC-DC buck converters with custom aircoils will drop down the incoming 20 VDC to the lower voltages. LDO regulators will provide the low noise power lines needed by the electronic. Special care has to be taken distributing the low voltage power to the electronics and sensors.