Thursday 10 April 2025
The quest for reliable data transmission has led scientists to develop a novel test system capable of evaluating the signal transmission quality in high-speed data links for the ATLAS experiment’s Inner Tracker upgrade. The new system, built using an FPGA-based data acquisition framework, can run simultaneous Bit Error Rate (BER) tests for up to 64 channels and generate virtual eye diagrams, allowing researchers to qualify the approximately 26,000 electrical links operating at a rate of 1.28 Gigabits per second.
The ATLAS experiment’s Inner Tracker upgrade requires high-bandwidth readout capabilities to ensure efficient data transmission. To achieve this, researchers have developed custom Twinax cables with polyethene dielectric and aluminium shielding, which meet the allocated signal loss budget of 13 decibels at 640 megahertz. However, testing such a large number of links using traditional methods would be time-consuming and impractical.
The new test system addresses this challenge by providing an automated Quality Control (QC) solution. The setup consists of two types of connectors: one for industry-standard miniDP cables and another for Type-1 Twinax bundle testing. Each connector is integrated into a Rear Transmission Module that supports four channels, allowing researchers to establish transmission loops and assess the signal transmission quality.
To calibrate the test system, researchers recorded transmission data using 1-meter and 5-meter miniDP cables connected via miniDP adapters between transmitter and receiver channels. The data revealed channel-to-channel variations in signal transmission, which were used to refine the calibration model for transmission variations. The results showed a linear correlation between Insertion Loss (IL) distributions and eye amplitude rates from BER scans.
The first prototype data link assembly was tested using the new system, featuring two ribbons with 10 Twinax links each. The results indicated that eight links failed to meet the performance threshold, with BER scan amplitudes below the established criterion of approximately 22%. This highlighted the need for further refinements in the manufacturing process.
The development of this test system has significant implications for the ATLAS experiment’s Inner Tracker upgrade. By providing an automated QC solution, researchers can ensure reliable data transmission and reduce the time-consuming manual testing process. The system’s scalability also allows it to be used for testing multiple assemblies simultaneously, making it a valuable tool for the experimental community.
In addition to its practical applications, this project demonstrates the importance of collaboration in scientific research.
Cite this article: “Revolutionizing Data Transmission: A Novel Test System for High-Speed Links in Particle Physics Detectors”, The Science Archive, 2025.
Fpga, Data Acquisition, Bit Error Rate, Virtual Eye Diagrams, Atlas Experiment, Inner Tracker Upgrade, Twinax Cables, Polyethene Dielectric, Aluminium Shielding, Quality Control.
