A heavy-ion collision facility called the cooler storage ring (CSR) external-target experiment (CEE) is scheduled in Lanzhou, China. The time measurement of the charged particles at the forward angle will be conducted by the external time-of-flight (eTOF) subsystem, which is built with multigap resistive plate chambers (MRPC). This work describes the tasks, performance criteria, detector layout, and prototype test results while outlining the technical design and development status of the CEE-eTOF wall. The effectiveness of the wall design has been validated using a FairRoot-based simulation, which is an essential part of the verification. With a $$3.2 \times 1.6~\textrm{m}^2$$3.2 × 1.6 m 2 coverage, a 60 ps overall time resolution, and a 2.6 m distance from the collision point, the eTOF wall enables the particle identification, system triggering, and event selection in cooperation with other related detectors. A novel structure called sealed MRPC will be applied to the subsystem. The design considerations of this type, prototype test, and results are also described in this paper.

This work reports the latest observations on the behavior of two Multigap Resistive Plate Chambers (MRPC) under wide high-luminosity exposures, which motivate the development and in-beam test of the sealed MRPC prototype assembled with low-resistive glass. The operation currently being monitored, together with previous simulation results, shows the impact of gas pollution caused by avalanches in gas gaps, and the necessity to shrink the gas-streaming volume. With the lateral edge of the detector sealed by a 3D-printed frame, a reduced gas-streaming volume of ~170 mL has been achieved for a direct gas flow to the active area. A high-rate test of the sealed MRPC prototype shows that, ensuring a 97% efficiency and 70 ps time resolution, the sealed design results in a stable operation current behavior at a counting rate of 3–5 kHz/cm². The sealed MRPC will become a potential solution for future high luminosity applications.

This work reports the development status of a software framework for the external Time-Of-Flight wall (eTOF) of the Cooler-storage-ring External-target Experiment (CEE). The framework is implemented on CeeRoot, a FairRoot-based simulation and analysis platform. The chains for eTOF simulation and analysis have been developed and described in this paper. The examination of such a structure is in parallel with the technical design and prototype developments. Simulation has given reasonable evaluations on the coverage, occupancy, rate condition, etc., which validated the system design. The analysis chain has been successfully applied to processing the cosmic test data and has contributed to the validation of the prototype performances. The CEE-eTOF software is a continuously refining framework for practice in real operations.

Since 2013, Muon Tomography technology has been developed at Tsinghua University. We have built up a prototype system named THUMTY (Tsinghua University cosmic ray Muon tomography facility) to do elementary research. Our research is focused on developing a muon NDT (Non Destructive Testing) system that will be used in homeland security operations such as custom inspections, airport security and so on. This muon NDT system is based on the MRPC (Multi-gap Resistive Plate Chamber) technology, thus the impact of the ambient temperature must be considered. In this paper, the performance of the MRPC with Freon/SF6/isobutene mixture and pure Freon gas at different temperatures (-15 degrees C, -10 degrees C, -5 degrees C, 5 degrees C, 15 degrees C and 25 degrees C) were studied. This study is important to develop a widely used stable cosmic ray detection system.