Q-Pix: Pixel-scale Signal Capture for Kiloton Liquid Argon TPC Detectors: Time-to-Charge Waveform Capture, Local Clocks, Dynamic Networks

Abstract: We describe a novel ionization signal capture and waveform digitization scheme for kiloton-scale liquid argon Time Projection Chamber (TPC) detectors. The scheme is based on a pixel-scale self-triggering `charge integrate/reset' block, local clocks running at unconstrained frequencies and dynamically established data networks. The scheme facilitates detailed capture of waveforms of arbitrary complexity from a sequence of varying time intervals, each of which corresponds to a fixed charge integral. An absolute charge auto-calibration process based on intrinsic $^{39}$Ar decay current is a major benefit. A flat electronic architecture with self-guided network generation provides exceptionally high resilience against single-point failure. Integrated photon detection, although highly speculative, may also be possible. The goal is optimized discovery potential. Much might be at stake.