Layout and performance of HPK prototype LGAD sensors for the High-Granularity Timing Detector

• Published in: Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment Accelerators, spectrometers, detectors and associated equipment, 2020-07, Vol.980 (C)
• Main Authors: Yang, X., Alderweireldt, S., Atanov, N., Ayoub, M. K., da Costa, J. Barreiro Guimaraes, García, L. Castillo, Chen, H., Christie, S., Cindro, V., Cui, H., D’Amen, G., Davydov, Y., Fan, Y. Y., Galloway, Z., Ge, J. J., Gee, C., Giacomini, G., Gkougkousis, E. L., Grieco, C., Grinstein, S., Grosse-Knetter, J., Guindon, S., Han, S., Howard, A., Huang, Y. P., Jin, Y., Jing, M. Q., Kiuchi, R., Kramberger, G., Kuwertz, E., Labitan, C., Lange, J., Leite, M., Li, C. H., Li, Q. Y., Liu, B., Liu, J. Y., Liu, Y. W., Liang, H., Liang, Z. J., Lockerby, M., Lyu, F., Mandić, I., Martinez-Mckinney, F., Mazza, S. M., Mikuž, M., Padilla, R., Qi, B. H., Quadt, A., Ran, K. L., Ren, H., Rizzi, C., Rossi, E., Sadrozinski, H. F. -W., Saito, G. T., Schumm, B., Schwickardi, M., Seiden, A., Shan, L. Y., Shi, L. S., Shi, X., Ferreira, A. Soares Canas, Sun, Y. J., Tan, Y. H., Tricoli, A., Wan, G. Y., Wilder, M., Wu, K. W., Wyatt, W., Xiao, S. Y., Yang, T., Yang, Y. Z., Yu, C. J., Zhao, L., Zhao, M., Zhao, Y., Zhao, Z. G., Zheng, X. X., Zhuang, X. A.
• Format: Article
• Language: English
• Subjects: HGTD; Instruments & Instrumentation; Low-Gain Avalanche Detector; NUCLEAR PHYSICS AND RADIATION PHYSICS; Nuclear Science & Technology; OTHER INSTRUMENTATION; Physics; Timing Detector
• ISSN: 0168-9002; 1872-9576

The High-Granularity Timing Detector is a detector proposed for the ATLAS Phase II upgrade. The detector, based on the Low-Gain Avalanche Detector (LGAD) technology, will cover the pseudo-rapidity region of 2.4 < |n| < 4.0 with two end caps on each side and a total area of 6.4 m2. The timing performance can be improved by implanting an internal gain layer that can produce signals with a fast rising edge. It significantly improves the signal-to-noise ratio. The required average timing resolution per track for a minimum ionizing particle is 30 ps at the start and 50 ps at the end of the HL-LHC operation. This is achieved with several layers of LGAD. The innermost region of the detector would accumulate a 1MeV neutron-equivalent fluence up to 2.5 1015 neq/cm2 including a safety factor of 1.5 before being replaced during the scheduled shutdowns. The addition of this new detector is expected to play an important role in the mitigation of high pile-ups at the HL-LHC. The layout and performance of the various versions of LGAD prototypes produced by Hamamatsu (HPK) have been studied by the ATLAS Collaboration. The breakdown voltages, depletion voltages, inter-pad gaps, collected charge as well as the time resolution have been measured and the production yield of large size sensors has been evaluated.