The IceCube Data Acquisition System: Signal Capture, Digitization, and Timestamping

TL;DR

The paper details the design, implementation, and initial performance of the IceCube neutrino observatory's data acquisition system, focusing on signal capture, digitization, and precise timestamping of optical signals in a challenging polar environment.

Contribution

It introduces the DOM Main Board data acquisition subsystem and demonstrates its successful operation and synchronization across the IceCube array.

Findings

System design meets performance goals

Successful synchronization with GPS clock

Reliable data transmission over copper wire-pair

Abstract

IceCube is a km-scale neutrino observatory under construction at the South Pole with sensors both in the deep ice (InIce) and on the surface (IceTop). The sensors, called Digital Optical Modules (DOMs), detect, digitize and timestamp the signals from optical Cherenkov-radiation photons. The DOM Main Board (MB) data acquisition subsystem is connected to the central DAQ in the IceCube Laboratory (ICL) by a single twisted copper wire-pair and transmits packetized data on demand. Time calibration is maintained throughout the array by regular transmission to the DOMs of precisely timed analog signals, synchronized to a central GPS-disciplined clock. The design goals and consequent features, functional capabilities, and initial performance of the DOM MB, and the operation of a combined array of DOMs as a system, are described here. Experience with the first InIce strings and the IceTop stations indicates that the system design and performance goals have been achieved.