Precise tracking of cosmic muons using the Time-over-Threshold property of NINO ASICs

This work reports on a cost-effective, simple front-end readout and data-acquisition system for a muon scattering tomography system based on Resistive Plate Chambers. The Time-over-Threshold (TOT) property of NINO ASICs has been exploited to extract position information and achieve precise tracking capability. Initial test measurements with a prototype Resistive Plate Chamber were performed using a low-cost FPGA coupled to the NINO ASIC for the event selection and handling of the TOT data. The relation between input pulse width and TOT has been established by analyzing the waveforms of the RPC signals. The TOT profile at different working voltages has been obtained by the FPGA and it has been fitted with the Gaussian distribution whose standard deviation represents an estimate of the tracking precision.