Development of analog signal transmission in LAr for DUNE

Abstract

The Deep Underground Neutrino Experiment (DUNE) is currently investigating a new prototype design for its second far detector module. The new concept proposes a vertical drift liquid argon time projection chamber, with a cathode at mid-height in the detector and anodes made of printed circuit boards, located at the top and bottom of the detector. In this context, the design of the photo-detection system needs to be revisited, opening a window of opportunity for further optimization and new developments. It is envisaged to distribute the photo-sensors (x-ARAPUCA) on the cathode surface. Such a system is required to operate within high-voltage surfaces, with both power supply and signal delivered using non-conductive materials. This article describes the on-going work to collect and read-out the signal of the photo-sensors, which are re-shaped into large tiles containing 160 SiPMs each. A new ganging scheme for the SiPMs is introduced. In particular, this article will focus on the proposed option to read out the sensors using an analog optical transmitter, that should ensure the transmission of the signals — with a wide dynamic range — to the outside of the cryostat to be digitized.