Speaker
Description
Low Gain Avalanche Detectors (LGADs) feature a fast rise time (~500 ps), exceptional time resolution (down to 17 ps), and the potential for very high repetition rates, with full charge collection in about 1 ns. These properties make them attractive for near-future experiments such as e⁺e⁻ Higgs factories (e.g., FCC-ee) and the ePIC detector at the Electron–Ion Collider. However, conventional LGADs face two main challenges in these contexts: intrinsically low granularity and the high power consumption of readout chips needed for precise timing. AC-coupled LGADs (AC-LGADs), in which the readout metal is AC-coupled through an insulating oxide layer, offer a promising solution to both issues. Their 100% fill factor and charge-sharing capabilities enable sub-pitch position resolution, surpassing the pitch / √12 limit of standard segmented detectors.
To fully evaluate AC-LGAD performance for these applications, detailed characterization in test beams is essential. Such facilities must provide timing and spatial resolutions significantly better than those of the devices under test, likely below 10 ps in timing and under 5 µm in position, to ensure accurate measurements.
