Description
Liquid Argon Time Projection Chambers (LArTPCs) are a premier technology used for the study of neutrino interactions. However, projective wire or strip readouts used for the measurement of ionization charge in these detectors suffer from ambiguities which are dependent on track orientation, and inhibit high-fidelity reconstruction of high-multiplicity topologies. We present LArPix, a novel, pixelated charge readout technology capable of delivering unambiguous 3D imaging of ionization charge in LArTPCs. Each LArPix chip is an Application Specific Integrated Circuit (ASIC) manufactured in 180-nm Bulk CMOS that provides 64 individual channels with charge amplification, self-triggering, and digital readout. LArPix has very low power dissipation and uses highly multiplexed digital communication allowing for large area coverage and high channel density in cryogenic environments. I/O is done through ASIC-to-ASIC communication, and is made fully redundant with Hydra Networking, a readout technique we present allowing data to traverse an arbitrarily defined path through an ASIC network, and preventing readout issues from individual ASIC failures. LArPix relies on standard PCB manufacturing techniques and is highly scalable for large scale experiments.
