A new study has modeled the gain suppression dynamics in Low Gain Avalanche Detectors (LGADs), a type of silicon sensor crucial for particle physics experiments and other applications requiring high temporal resolution. The research for the first time couples avalanche multiplication with multi-body Coulomb interaction, offering a deeper understanding of how the charge density generated by the avalanche affects detector efficiency. This advance is fundamental for optimizing the design and performance of LGADs, which are essential for event reconstruction in high-luminosity environments, such as those at the Large Hadron Collider (LHC).

LGADs operate by amplifying the signal produced by an incident particle through an electron-hole avalanche process within a gain layer. However, at high particle densities, the large amount of charge generated can create a local electric field that reduces avalanche efficiency, a phenomenon known as gain suppression. The developed model addresses this complexity by considering how electrostatic interactions between charge carriers (electrons and holes) influence the effective electric field and, consequently, signal multiplication. This approach allows for more accurate prediction of LGAD behavior under extreme conditions, where gain suppression is most pronounced.

The ability to accurately simulate gain suppression is vital for the development of the next generation of detectors, especially those intended for future LHC upgrades, such as the High-Luminosity LHC (HL-LHC). In these environments, particle density will be significantly higher, making gain suppression a critical factor to consider. The model not only helps to understand the current limitations of LGADs but also provides a tool to explore new architectures and materials that can mitigate this effect, paving the way for more robust and efficient detectors for high-energy physics and other areas such as medical imaging or neutron detection.