Broader course for all
Novel strategies for high-granularity and radiation hardness LGAD sensors and front-end electronics
Michele Casalle (KIT)
Abstract
Low-Gain Avalanche Diodes (LGADs) are emerging as a highly effective solution for 4D-tracking, thanks to their exceptional time resolution and strong resistance to high radiation fluence. These sensors are crucial in applications demanding high temporal precision, such as high-energy physics experiments at CERN’s Large Hadron Collider, medical imaging, and advanced scientific instrumentation. A key advantage of LGADs is their ability to produce strong signals while maintaining rapid response times, typically within tens of picoseconds. The primary goal of this lecture is to provide a comprehensive overview of the principles, design, and applications of ultrafast LGAD sensors. The course is structured into three sections:
1. Design of Ultrafast LGAD Sensors
This section delves into the key parameters and strategies for designing ultrafast silicon sensors. Emphasis will be placed on the specialized gain layer that enables high signal amplification and the importance of minimizing material budget, which is critical in applications where space and weight are constraints.
2. Front-End Electronics and Readout Strategies
This section covers the strategies for managing high-speed, low-noise signals while maintaining minimal power consumption, ensuring that the temporal resolution provided by LGAD sensors is preserved. Key components include Charge-Sensitive Amplifiers (CSA), transimpedance amplifiers, and shaper circuits that optimize the signal-to-noise ratio (SNR) and prepare signals for digitization. Additionally, Time-to-Digital Converters (TDCs), which measure the precise time of signal arrival and the time-over-threshold with picosecond accuracy, will be discussed. TDCs are integral to the readout chain, leveraging LGADs' temporal precision, making them essential for applications like particle tracking in collider experiments.
3. Applications and Future Directions
This final section provides an overview of the current applications of LGAD sensors and their associated front-end electronics in high-energy physics and medical imaging. It will also explore future challenges and potential advancements, such as the use of novel semiconductor materials like silicon carbide (SiC) to enhance radiation hardness and overall performance.
Conclusion
Ultrafast LGAD sensors, paired with advanced front-end electronics, represent a significant leap forward in high-speed detection systems, offering unprecedented temporal resolution. These qualities make LGADs indispensable in a wide range of cutting-edge applications. Ongoing research and innovation are expected to further enhance the performance, scalability and cost-effectiveness of LGAD technology and its electronics, broadening their applicability across various fields.
