Data acquisition and management system for the CMB polarization experiment: Simons Array

Abstract

The Simons Array upgrades the POLARBEAR experiment, which measures the cosmic microwave background from the Atacama Desert in Chile, with three newly developed receivers. Each receiver has 7,588 transition-edge sensor bolometers with a raw data rate of approximately 20 MB/s. This significantly increased data rate required us to develop a new data-acquisition (DAQ) and data-management system. As the network bandwidth from our observatory to our data-storage sites outside Chile is not high enough to send all the raw data, we compress the raw data on-site. The expected yearly compressed data rate is approximately 60 TB from each receiver. We have also developed a new housekeeping DAQ system. The new housekeeping DAQ system is a distributed system to handle the various newly added monitoring systems and to better understand our instruments and environments. Those data can also be fetched by another module for real-time monitoring of our instrument from all over the world with latencies on the order of minutes. We deployed the first receiver in late 2018 and started the commissioning of the DAQ system. The DAQ system has been working without significant problems and already accumulates a considerable amount of the new receiver data from the commissioning observations. In this presentation, we summarize and report the status of the new systems.