Charge collection study with the ATLAS ITk prototype silicon strip sensors ATLAS17LS

Journal Article · Thu Sep 03 00:00:00 EDT 2020 · Nuclear Instruments and Methods in Physics Research. Section A, Accelerators, Spectrometers, Detectors and Associated Equipment

DOI:https://doi.org/10.1016/j.nima.2020.164422· OSTI ID:1851309

Hara, K. ^[1]; Abidi, S. H. ^[2]; Affolder, A. A. ^[3]; Allport, P. ^[3]; Basso, M. J. ^[2]; Casha, A. ^[2]; Cindro, V. ^[4]; Ciungu, B. M. ^[2]; Dette, K. ^[2]; Escobar, C. ^[5]; Fadeyev, V. ^[6]; Freeman, P. ^[3]; Garcia, C. ^[5]; Gonella, L. ^[3]; Gunnell, J. ^[6]; Harada, D. ^[1]; Helling, C. ^[6]; Hunter, A. ^[3]; Kisliuk, D. ^[2]; Kopsalis, I. ^[3] ; Kroll, J. ^[7]; Lacasta, C. ^[5]; Latonova, V. ^[8]; Mandić, I. ^[4]; Martinez-Mckinney, F. ^[6]; Mikestikova, M. ^[7]; Miñano, M. ^[5]; Nakamura, K. ^[9]; Nicolini, J. ^[2]; Onaru, K. ^[1]; Orr, R. S. ^[2]; Pyatt, S. ^[3]; Saito, K. ^[1]; Sato, K. ^[1]; Simpson-Allsop, C. ^[3]; Soldevila, U. ^[5]; Teuscher, R. ^[2]; Thomas, J. ^[6]; Unno, Y. ^[9]; Wada, S. ^[1]; Worm, S. ^[3]; Zatocilova, I. ^[7]

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1. Univ. of Tsukuba (Japan)
2. Univ. of Toronto, ON (Canada)
3. Univ. of Birmingham (United Kingdom)
4. Jozef Stefan Inst. (IJS), Ljubljana (Slovenia)
5. Consejo Superior de Investigaciones Cientificas (CSIC), Valencia (Spain)
6. Univ. of California, Santa Cruz, CA (United States)
7. Academy of Sciences of the Czech Republic, Prague (Czech Republic)
8. Academy of Sciences of the Czech Republic, Prague (Czech Republic); Charles Univ., Prague (Czech Republic)
9. National Lab. for High Energy Physics (KEK), Tsukuba (Japan)

The inner tracker of the ATLAS detector is scheduled to be replaced by a completely new silicon-based inner tracker (ITk) for the Phase-II of the CERN LHC (HL-LHC). The silicon strip detector covers the volume $40<R<100$ cm in the radial and $\left|z\right|<$300 cm in the longitudinal directions. The silicon sensors for the detector will be fabricated using the n ${}^{+}$-on-p 6-inch wafer technology, for a total of 22,000 wafers. Here, intensive studies were carried out on the final prototype sensors ATLAS17LS fabricated by Hamamatsu Photonics (HPK). The charge collection properties were examined using penetrating ⁹⁰Sr $\beta$-rays and the ALIBAVA fast readout system for the miniature sensors of 1 cm $\times$1 cm in area. The samples were irradiated by protons in the 27 MeV Birmingham Cyclotron, the 70 MeV CYRIC at Tohoku University, and the 24 GeV CERN-PS, and by neutrons at Ljubljana TRIGA reactor for fluence values up to 2 × 10¹⁵ n ${}_{\mathrm{eq}}$/cm ${}^2$. The change in the charge collection with fluence was found to be similar to the previous prototype ATLAS12, and acceptable for the ITk. Sensors with two active thicknesses, $300\mathrm{\mu }\mathrm{m}$ (standard) and $240\mathrm{\mu }\mathrm{m}$ (thin), were compared and the difference in the charge collection was observed to be small for bias voltages up to 500 V. Some samples were also irradiated with gamma radiation up to 2 MGy, and the full depletion voltage was found to decrease with the dose. This was caused by the Compton electrons due to the ⁶⁰Co gamma radiation. To summarize, the design of the ATLAS17LS and technology for its fabrication have been verified for implementation in the ITk. We are in the stage of sensor pre-production with the first sensors already delivered in January of 2020.

• Research Organization: Univ. of California, Santa Cruz, CA (United States)
• Sponsoring Organization: USDOE Office of Science (SC); Japan Society for the Promotion of Science (JSPS); Ministry of Education, Youth and Sports of the Czech Republic; Charles University Grant Agency (GA UK); Natural Sciences and Engineering Research Council of Canada (NSERC)
• Grant/Contract Number: SC0010107; 16H06491A; LM2015058; GAUK942119; SAPP-J-2018-00
• OSTI ID: 1851309
• Alternate ID(s): OSTI ID: 1809333
• Journal Information: Nuclear Instruments and Methods in Physics Research. Section A, Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 983, Issue C; ISSN 0168-9002
• Publisher: Elsevier
• Country of Publication: United States
• Language: English

Related Subjects

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
instruments &amp; instrumentation
nuclear science &amp; technology
physics
ATLAS ITk
microstrip sensor
charge collection
radiation damage