Development of a radiation tolerant fine pitch planar pixel detector by HPK/KEK

• Published in: Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment Accelerators, spectrometers, detectors and associated equipment, 2019-04, Vol.924, p.64-68
• Main Authors: Nakamura, Koji, Suzuki, Junki, Tokutake, Hitomi, Sato, Kazuyuki, Abo, Yohei, Jinnouchi, Osamu, Hanagaki, Kazunori, Hara, Kazuhiko, Kamada, Shintaro, Nakamura, Yuto, Nanjyo, Hajime, Ikegami, Yoichi, Sawada, Yasunori, Togawa, Manabu, Uchiyama, Kazuki, Unno, Yoshinobu, Wada, Sayaka, Yamamoto, Daiki, Yamamoto, Hirokazu, Yamamura, Kazuhisa
• Format: Article
• Language: English
• Subjects: ATLAS upgrade; Fine pitch pixel; Hadron collider; HEP; ITK; LHC; Planar pixel
• ISSN: 0168-9002; 1872-9576
• DOI: 10.1016/j.nima.2018.09.015

In the recent development of pixel detectors for the inner part of the ATLAS detector upgrade of the High Luminosity LHC, a thin, typically 150 μm, planar pixel detector has been developed. To reduce hit occupancy, the pixel size is smaller compared to the currently operating pixel detector in ATLAS and the 2 pitch options, 50 μm×50μm and 25μm×100μm, are readout by the same 50μm×50μm pitch readout ASIC. To evaluate the performance of the fine pitch pixel detector, two methods are tested, a) emulated using the current ASIC (FE-I4) using non-uniform size of pixel, where two 50μm×250μm pixels are spitted to 50μm×50μm and 50μm×450μm, (b) used new ASIC (FE65p2) with full 50μm×50μm pitch. The FE65p2 is the prototype ASIC produced by TSMC using 65 nm CMOS process, with an expected lower noise than FE-I4. In this paper, basic devices performance and testbeam results before and after irradiation are presented.