Advanced Readout Electronics System for Portable Cosmic Ray Muon Detection

Ground cosmic ray muon measurements have extensive applications in weather and climate change prediction and muon tomography. However, for comprehensive understanding of the relationship between cosmic ray muon and various weather phenomena, the cosmic ray muon flux needs to be determined accurately at various geographical locations. Toward this objective, this report presents an advanced readout electronics system with a multichannel application-specific integrated circuit (ASIC) chip for a portable cosmic ray muon detector. This ASIC chip consists of high-speed comparators and an excellent time-resolution digital circuit module. Furthermore, it can provide all-digital outputs associated with the flux and zenith angles of incident cosmic ray muons. A 32-channel prototype readout ASIC chip was designed and fabricated in a 180-nm mixed-signal CMOS process, and the chip size was 3.9 mm². A double-layer plastic scintillator muon detector was used to test the performance of this chip. The time resolution of the chip was approximately 5 ns, and its power consumption was only 1.6 mW/channel. Compared with the existing muon readout electronics system, the proposed system has advantages such as low cost, low power, high reliability, small size, and lightweight and is highly suitable for portable real-time cosmic ray muon detection. The final version of this chip will be used to construct a ground cosmic ray muon measurement network for long-term monitoring of cosmic ray muon flux variations around the world.