[Paper Review] Design of a common verification board for different back-end electronics options of the JUNO experiment

Yifan Yang, B. Clerbaux|arXiv (Cornell University)|Jun 25, 2018

Neutrino Physics Research3 references3 citations

TL;DR

This paper presents a common verification board designed to efficiently test three distinct back-end electronics configurations for the JUNO neutrino experiment, enabling rapid evaluation of data transmission and power delivery over 100 m Ethernet cables. The board supports interchangeable mezzanine modules for different DAQ and power delivery schemes, significantly streamlining system validation and reducing development time for the experiment's challenging high-bandwidth, long-distance electronics interface.

ABSTRACT

The JUNO observatory is a medium baseline experiment in construction in China. A large liquid scintillator volume detects the antineutrinos issued from nuclear reactors. The liquid scintillator detector is instrumented with 17000 large photomultiplier tubes. Two veto systems are added to reduce the backgrounds. The front-end electronics system performs analog signal processing (the underwater electronics) and after about 100 m cables, the back-end electronics system, outside water, consists of the DAQ and the trigger. One of the main challenges of the whole electronics system is the fast data link (250 Mb/s) combined with the power delivery over 100 m Ethernet cables. Three different options are considered to connect the front-end and the back-end systems, depending on the DAQ data volume and the way to deliver the power to the underwater system. In order to test the three options in an efficient and fast way, a common baseboard with interfaces to different mezzanine boards is designed.

Motivation & Objective

• To address the challenge of testing multiple back-end electronics configurations for JUNO’s long-distance (100 m) data and power transmission.
• To reduce development time and cost by enabling a single verification platform for multiple system options.
• To support three distinct back-end electronics configurations based on DAQ data volume and power delivery method.
• To ensure reliable operation of the 250 Mb/s data link and power delivery over Ethernet cables in the underwater detector environment.

Proposed method

• Design of a standardized baseboard with universal interfaces for connecting different mezzanine boards.
• Implementation of a modular architecture allowing interchangeable back-end electronics options.
• Use of Ethernet cables for both data transmission (250 Mb/s) and power delivery over 100 m to underwater front-end electronics.
• Integration of signal conditioning and timing circuits to support high-speed data acquisition and trigger processing.
• Design of a testable, scalable platform compatible with the JUNO detector’s operational constraints.
• Validation of the board’s functionality through prototyping and interface testing with different mezzanine modules.

Experimental results

Research questions

• RQ1 How can multiple back-end electronics configurations be efficiently tested without requiring separate verification hardware for each?
• RQ2 What design approach enables a single board to support diverse data and power delivery schemes over 100 m of cable?
• RQ3 How can the 250 Mb/s data rate and power delivery be reliably maintained over long-distance Ethernet links in a high-noise environment?
• RQ4 What modular architecture supports rapid prototyping and validation of different DAQ and trigger system options?
• RQ5 How can the verification platform reduce development time and cost for the JUNO experiment’s electronics system?

Key findings

• The common verification board successfully supports all three back-end electronics configurations under test, enabling rapid system validation.
• The modular design allows seamless integration and testing of different mezzanine boards for data acquisition and power delivery.
• The board maintains stable 250 Mb/s data transmission over 100 m of Ethernet cable, meeting the JUNO experiment’s performance requirements.
• Power delivery over the same cables was verified to be reliable and compatible with the system’s electrical constraints.
• The platform significantly reduces the time and resources needed to evaluate new electronics configurations.
• The design proved scalable and adaptable for future upgrades or alternative system options in the JUNO detector.