Full-Chain Diagnostics of a 1408-Channel TPC Readout System

Created on April 26, 2026

2026   ·   TPC   detector   DAQ   debugging   electronics

Background

Large-scale liquid xenon Time Projection Chamber (TPC) detectors rely on the stability and uniformity of thousands of readout channels. I carried out a systematic diagnostic campaign on a 1408-channel TPC readout system at the Tsung-Dao Lee Institute, targeting signal abnormalities such as unstable baselines, excessive noise, and dead channels.

System Overview

The full signal chain includes:

  • Detector / PMT
  • Flange feedthrough
  • High-voltage (HV) system
  • Amplifiers
  • FADC modules
  • Signal cables

Each stage introduces distinct failure modes, requiring structured debugging.

Methodology

Layered Debugging

The system was decomposed into:

  • Hardware layer (flange, HV)
  • Electronics layer (amplifier, FADC)
  • Signal layer (waveform quality)

This allowed progressive fault isolation.

Channel-Level Analysis

Each channel was evaluated using:

  • Baseline
  • RMS noise
  • Waveform morphology
  • Rate stability

Abnormal channels were flagged and traced upstream.

Team Coordination

I led three students to execute channel-wise diagnostics, ensuring consistent criteria and coverage.

Data Integration

To handle distributed measurements, I built a database to unify all diagnostic results:

  • Aggregation of multi-user measurements
  • Standardized channel status records
  • Queryable fault tracking
  • Cross-run comparison

This eliminated inconsistencies and improved debugging efficiency.

Results

  • Full diagnostic coverage of all 1408 channels
  • Fault localization across HV, cabling, electronics, and FADC
  • Established a reusable debugging workflow
  • Improved efficiency via centralized data management

Summary

This work provides a scalable framework for debugging large-channel-count detector systems, combining structured diagnostics with data integration.