The Mu3e Data Acquisition

TL;DR

The Mu3e data acquisition system is designed to handle high data rates from a particle physics experiment searching for rare muon decays, utilizing advanced sensors, FPGA networks, and GPU-based processing for efficient data filtering and storage.

Contribution

This paper presents the system design and hardware implementation of Mu3e's data acquisition and filter farm, enabling real-time processing of high-rate particle physics data.

Findings

Achieves data reduction from 100 Gbit/s to 100 Mbyte/s

Utilizes FPGA network for high-speed data transport

Employs GPU-based algorithms for track and vertex reconstruction

Abstract

The Mu3e experiment aims to find or exclude the lepton flavour violating decay $\mu^+\to e^+e^-e^+$ with a sensitivity of one in 10$^{16}$ muon decays. The first phase of the experiment is currently under construction at the Paul Scherrer Institute (PSI, Switzerland), where beams with up to 10$^8$ muons per second are available. The detector will consist of an ultra-thin pixel tracker made from High-Voltage Monolithic Active Pixel Sensors (HV-MAPS), complemented by scintillating tiles and fibres for precise timing measurements. The experiment produces about 100 Gbit/s of zero-suppressed data which are transported to a filter farm using a network of FPGAs and fast optical links. On the filter farm, tracks and three-particle vertices are reconstructed using highly parallel algorithms running on graphics processing units, leading to a reduction of the data to 100 Mbyte/s for mass storage and offline analysis. The paper introduces the system design and hardware implementation of the Mu3e data acquisition and filter farm.