Investigation of signal characteristics and charge sharing in AC-LGADs with laser and test beam measurements

Journal Article · Wed Oct 19 00:00:00 EDT 2022 · Nuclear Instruments and Methods in Physics Research. Section A, Accelerators, Spectrometers, Detectors and Associated Equipment

DOI:https://doi.org/10.1016/j.nima.2022.167541· OSTI ID:1913808

Ott, Jennifer ^[1]; Letts, Sean ^[1]; Molnar, Adam ^[1]; Ryan, Eric ^[1]; Wong, Marcus ^[1]; Mazza, Simone M. ^[1]; Nizam, Mohammad ^[1]; Sadrozinski, Hartmut F.-W. ^[1]; Schumm, Bruce ^[1]; Seiden, Abraham ^[1]; Shin, K.-W. Taylor ^[1]; Heller, Ryan ^[2]; Madrid, Christopher ^[2]; Apresyan, Artur ^[2]; Brooks, William K. ^[3]; Chen, Wei ^[4]; D’Amen, Gabriele ^[4]; Giacomini, Gabriele ^[4]; Goya, Ikumi ^[5]; Hara, Kazuhiko ^[5] ; Kita, Sayuka ^[5]; Los, Sergey ^[2]; Nakamura, Koji ^[6]; Peña, Cristián ^[2]; San Martin, Claudio ^[7]; Ueda, Tatsuki ^[5]; Tricoli, Alessandro ^[4]; Xie, Si ^[8]

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1. Univ. of California, Santa Cruz, CA (United States)
2. Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
3. Universidad Tecnica Federico Santa Maria, Valparaiso (Chile); Millenium Institute for Subatomic Physics at the High-Energy Frontier (SAPHIR) of ANID, Santiago (Chile)
4. Brookhaven National Lab. (BNL), Upton, NY (United States)
5. Univ. of Tsukuba (Japan)
6. High Energy Research Organization, Tsukuba (Japan)
7. Universidad Tecnica Federico Santa Maria, Valparaiso (Chile)
8. Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); California Institute of Technology (CalTech), Pasadena, CA (United States)

AC-LGADs, also referred to as resistive silicon detectors, are a recent development of low-gain avalanche detectors (LGADs), based on a sensor design where the multiplication layer and n⁺ contact are continuous, and only the metal layer is patterned. In AC-LGADs, the signal is capacitively coupled from the continuous, resistive n⁺ layer over a dielectric to the metal electrodes. Therefore, the spatial resolution is not only influenced by the electrode pitch, but also the relative size of the metal electrodes. Signal propagation between the metallized areas and charge sharing between electrodes plays a larger role in these detectors than in conventional silicon sensors read out in DC mode. AC-LGADs from two manufacturers were studied in beam tests and with infrared laser scans. The impact of n⁺ layer resistivity and metal electrode pitch on the charge sharing and achievable position resolution is shown. For strips with 100 μm pitch, a resolution of ¡ 5 μm can be reached. Additionally, the charge sharing between neighboring strips is investigated in more detail, indicating the induction of signal charge and subsequent re-sharing over the n⁺ layer. Furthermore, an approach to identify signal sharing over large distances is presented.

• Research Organization: Brookhaven National Laboratory (BNL), Upton, NY (United States); Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States)
• Sponsoring Organization: USDOE Office of Science (SC), High Energy Physics (HEP); US-Japan Science and Technology Cooperation Program in High Energy Physics; Chilean ANID PIA/APOYO; Ministry of Education, Culture, Sports, Science and Technology (MEXT); Finnish Cultural Foundation
• Grant/Contract Number: SC0012704; AC02-07CH11359
• OSTI ID: 1913808
• Alternate ID(s): OSTI ID: 23201267
• Report Number(s): BNL-223886-2023-JAAM
• Journal Information: Nuclear Instruments and Methods in Physics Research. Section A, Accelerators, Spectrometers, Detectors and Associated Equipment, Journal Name: Nuclear Instruments and Methods in Physics Research. Section A, Accelerators, Spectrometers, Detectors and Associated Equipment Vol. 1045; ISSN 0168-9002
• Publisher: Elsevier
• Country of Publication: United States
• Language: English

Related Subjects

47 OTHER INSTRUMENTATION
AC-LGAD
beam test
charge sharing
ultrafast timing