Precision measurement of muon decay using custom coincidence electronics

Duration

February-April 2026

Institution

Northeastern University Department of Physics

Tags

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Particle Physics

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Electronics

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Particle Detection

Research Question

The objective of this experiment was to measure the mean lifetime of cosmic-ray muons by capturing and timing individual particle arrivals and their subsequent decays. This required engineering a reliable detection system capable of isolating genuine, microsecond-scale decay events from ambient background noise and accidental coincidences.

Methods & Instrumentation

  • Configured a dual-scintillator detection apparatus coupled with photomultiplier tubes (PMTs)

  • Characterized PMT response curves to optimize supply voltages and maximize the signal-to-noise ratio

  • Built a hardware signal-processing chain using discriminators, AND logic gates, and dual-gate generators to create a precise coincidence triggering system

  • Interfaced the detection hardware with a National Instruments PCI-6221 DAQ card running on an 80 MHz clock

  • Developed custom C# software in Visual Studio using DAQmx libraries to control data acquisition and record high-resolution time intervals

  • Analyzed the resulting dataset using the Binned Maximum Likelihood method, optimizing an exponential decay model that mathematically accounted for constant background noise

Results & Significance

  • Successfully captured and processed 1045 valid decay events over a 79-hour continuous runtime

  • Calculated a mean muon lifetime of 2.184 ± 0.073 µs

  • Achieved a highly accurate final measurement that fell within 0.18 standard deviations of the accepted literature value (2.197 µs), proving the efficacy and precision of the custom hardware-software stack