The Continuous Readout Stream of the MicroBooNE Liquid Argon Time Projection Chamber for Detection of Supernova Burst Neutrinos

TL;DR

This paper discusses the implementation and optimization of a continuous data readout system for the MicroBooNE liquid argon TPC, enabling detection of supernova neutrinos despite high background noise and data volume challenges.

Contribution

It introduces a real-time data compression and processing system for continuous LArTPC readout, enhancing supernova neutrino detection capabilities.

Findings

Optimized FPGA-based data compression algorithms for continuous readout.

Demonstrated detection of low-energy electrons from cosmic-ray muons.

Achieved effective data reduction suitable for supernova neutrino detection.

Abstract

The MicroBooNE continuous readout stream is a parallel readout of the MicroBooNE liquid argon time projection chamber (LArTPC) which enables detection of non-beam events such as those from a supernova neutrino burst. The low energies of the supernova neutrinos and the intense cosmic-ray background flux due to the near-surface detector location makes triggering on these events very challenging. Instead, MicroBooNE relies on a delayed trigger generated by SNEWS (the Supernova Early Warning System) for detecting supernova neutrinos. The continuous readout of the LArTPC generates large data volumes, and requires the use of real-time compression algorithms (zero suppression and Huffman compression) implemented in an FPGA (field-programmable gate array) in the readout electronics. We present the results of the optimization of the data reduction algorithms, and their operational performance. To demonstrate the capability of the continuous stream to detect low-energy electrons, a sample of Michel electrons from stopping cosmic-ray muons is reconstructed and compared to a similar sample from the lossless triggered readout stream.