Speaker
Description
In order to cope with the occupancy and radiation doses expected at the High-Luminosity LHC, the ATLAS experiment will replace its Inner Detector with an all-silicon Inner Tracker (ITk), consisting of pixel and strip subsystems. The strip subsystem will be built from modules, consisting of one n$^{+}$-in-p silicon strip sensor, manufactured by Hamamatsu Photonics, and one or two PCB hybrids containing the front-end electronics glued directly to the sensor. A powerboard, containing an HV switch, a monitoring and control ASIC, and a DC-DC converter, is also glued to the sensor.
In the last two years, several prototype ITk strip modules have been tested using beams of high energy electrons and charged pions produced at the DESY-II and CERN SPS testbeam facilities. Tracking was provided by EUDET telescopes, consisting of six Mimosa26 pixel planes, giving a resolution around 2 µm. The modules tested are built from two sensor types: the rectangular ATLAS17LS, which will be used in the central barrel region of the detector, and the annular ATLAS12EC, which will be used in the innermost ring (R0) of the forward endcap region. Each sensor geometry has been tested using both the final prototype version of the front-end electronics, known as "star" chipset, as well as a previous prototype chipset developed for lower trigger rate specification. Additionally, a structure with two R0 modules positioned back-to-back has been measured, demonstrating space point reconstruction using the stereo angle of the strips. Finally, two R0 modules, one with each chipset, have been measured after irradiation to 50% beyond the expected end-of-lifetime fluence.
The data obtained allow for thorough tests of the module performance, including charge collection, noise occupancy, detection efficiency, and tracking performance. Additionally, the excellent tracking resolution allows for detailed studies of various sensor features. The results give confidence that the ITk strip detector will meet the requirements of the ATLAS experiment.
| Submission declaration | Original and unpublished |
|---|
