Speaker
Mr
Matteo Centis Vignali
(University of Hamburg)
Description
The high-luminosity upgrade of the Large Hadron Collider, foreseen for 2025, neces-
sitates the replacement of the tracker of the CMS experiment. The innermost layer of
the new pixel detector will be exposed to severe radiation corresponding to a 1 MeV
neutron equivalent fluence up to Φ eq = 2 · 10 16 cm −2 and an ionizing dose of ≈ 10 MGy
after an integrated luminosity of 3000 fb −1 . Silicon crystals grown with different methods
and sensor designs are under investigation in order to optimize the sensors for such high
fluences. Thin planar silicon sensors are good candidates to achieve this goal, since the
degradation of the signal produced by traversing particles is less severe than for thicker
devices.
Epitaxial pad diodes and strip sensors irradiated up to fluences of Φ eq = 1.3·10 16 cm −2
have been characterized in laboratory measurements and beam tests at the DESY II
facility. The active thickness of the strip sensors and pad diodes is 100 μm. In addition,
strip sensors produced using other growth techniques with a thickness of 200 μm have
been studied.
As the noise of the sensors increases with the accumulated fluence, the track informa-
tion provided by the beam telescope is used to improve the separation of signal and noise
in the strip sensors measurements, hereby improving the spectra of the collected charge.
In this talk, the results obtained for p-bulk sensors are shown.
Primary author
Mr
Matteo Centis Vignali
(University of Hamburg)
