arXiv subjects

Baojun Yan

Publications and source records attributed to Baojun Yan.

3 recordsLinked to original sources

arXiv2024

Conceptual Design of the Muonium-to-Antimuonium Conversion Experiment (MACE)

The spontaneous conversion of muonium to antimuonium is one of the interesting charged lepton flavor violation phenomena offering a sensitive probe of potential new physics and serving as a tool to constrain the parameter space beyond the Standard Model. The Muonium-to-Antimuonium Conversion Experiment (MACE) is designed to utilize a high-intensity muon beam, a Michel electron magnetic spectrometer, a positron transport system, and a positron detection system, to either discover or constrain this rare process with a conversion probability of $\mathcal{O}(10^{-13})$. This article presents an overview of the theoretical framework as well as a detailed description of the experimental design for the search for muonium-to-antimuonium conversion.

hep-ex↗

arXiv2023

Simulating the secondary electron avalanche of MCP by Geant4

Nowadays, Microchannel Plate (MCP), as a kind of electron multipliers based on the secondary electron emission, is widely used in many high-sensitive experiments, such as neutrino detection, which require the noise to be as low as possible, while the conventional straight-channel MCP will inevitably have ion feedback, resulting in the sequential after-pulses being the major source of noise. Normally, the problem can be effectively avoided by coupling two straight-channel MCPs in cascade and combining the channels into a `V` shape known as chevron MCPs, but this method is limited by the manufacturing techniques due to the unavoidable gap between the two pieces that will worsen the resolution and peak-to-valley ratio. However, the ion feedback can be inhibited significantly for MCPs with curved channels. Based on Geant4, we investigate how the geometrical parameters of curved-channel MCP influence the gain and get the optimum pore diameter for an MCP to reach the maximum gain with fixed thickness and applied voltage. Additionally, the track-by-track simulation reveals that the average acceleration distance of a secondary electron inside the curved-channel is approximately 20 um when the applied voltage, length-to-diameter ratio and pore diameter are 950 V, 50:1 and 20 um, respectively.

physics.ins-det↗

arXiv2023

MCPSim: A Geant4-based generic simulation toolkit for electron multipliers represented by Microchannel Plate

The simulation of the instruments based on the cascade multiplication of electrons has always been an important and challenging subject in no matter high energy physics, astrophysics, radiography and other fields. In this work, a generic simulation toolkit is developed based on Geant4, ROOT and CADMesh toolkits for the electron multipliers based on the emission process of secondary electrons, especially for Microchannel Plate (MCP). Geometry of instruments can be directly imported by standard CAD files and multiple kinds of electromagnetic fields are supported. MCPSim is capable for simulating the general hadronic, weak and electromagnetic processes together with secondary electron emission, which provides a wider range of applications. Users are able to configure the simulation and define the output information by a simple textfile. By comparing with experimental measurements, good agreement is found. MCPSim is expected to guide the design and optimization of such electron multipliers and will be continuously developed and maintained to better satisfy the present and future requirements.

physics.ins-det↗