Speaker
Description
During the third long LHC shutdown (2026-2030), the ALICE Inner
Tracking System will undergo an extensive upgrade, where the three in-
nermost layers of the detector will be replaced by ultra-thin (50 μm) wafer-
scale silicon sensors, that will be bent around the beam pipe. The very
first sensor prototypes were developed, called the MOnolithic Stitched
Sensor (MOSS), consisting of 10 repeated sensor units (RSU) stitched to-
gether. A single-RSU sensor, referred to as the babyMOSS, was produced
to ease the sensors characterization studies.
The babyMOSS sensor has been rigorously studied in various test
beams in terms of its detection efficiency, spatial resolution and cluster
size. In addition to the test beams, the babyMOSS sensor will also be char-
acterized using cosmic muons. For this purpose, a compact babyMOSS
cosmics telescope is currently being commissioned at Lund University.
The telescope comprises 4 babyMOSS sensors as tracking planes and one
device under test (DUT), placed in the middle, spaced 3 cm apart. The
trigger signal is handled by the FPGA of the trigger board with manually
set trigger conditions.
To characterize the babyMOSS sensor using cosmics, several software
developments are in progress, that deal with data acquisition and analysis.
For instance, customized EUDAQ2 software processes have been imple-
mented, that allow controlling the underlying detector hardware. Data
management routines have been developed to select only the events con-
taining particle hits. These raw events are then converted to standard
EUDAQ2 format using a dedicated Event Converter. The analysis is per-
formed using Corryvreckan framework with the main challenge being track
reconstruction for non-perpendicular tracks.
This work presents the design of the babyMOSS cosmics telescope,
the implementation of software processes and some of the first results of
the sensor’s detection efficiency, cluster size and fake-hit rate, obtained by
analyzing data collected using the telescope.