Speaker
Description
To improve scintillator-based muon detectors relying on wavelength-shifting (WLS) fibers, high photon detection efficiency and precise time-resolved readout are key requirements. This work presents ANDESPix, an 18x110 pixel single-photon avalanche diode (SPAD) array in a 110 nm CMOS process featuring a dedicated time-to-digital converter (TDC) per pixel. It combines fully parallel per-pixel time-stamping with a hierarchical event-driven, zero-suppressed readout architecture optimized for sparse, high-resolution, continuous time-resolved photon detection.
Key performance measures are evaluated, focusing on the Impulse Response Function (IRF) and TDC uniformity across the sensor array. Complementary simulations analyze the physical limitations in photon yield within WLS fiber setups and demonstrate that the observed TDC differential non-linearity (DNL) is not the key intrinsic detector limitation. Comprehensive experimental detector characterization including photon pulse shape analysis is currently ongoing.
Finally, upcoming developments to expand functionality and efficiency in future detector iterations are presented. These include integrated coincidence logic to suppress dark noise and reduce data bandwidth, an advanced Gated Ring Oscillator (GRO)-based TDC architecture for improved timing resolution, and the transition to a digital-on-top design flow for improved timing control, logic implementation and streamlined chip implementation.