Speaker
Description
To handle the tenfold increase in radiation from the High-Luminosity LHC, CMS will
replace its endcap calorimeters with the High-Granularity Calorimeter (HGCAL).
Silicon pad sensors, covering an area of 620 m2 in the electromagnetic and
high-radiation hadronic regions, must withstand fluences of up to 1e16 neq/cm2.
They are fabricated on 8-inch p-type wafers with thicknesses of 120, 200, and
300 μm. Each wafer also includes dedicated test structures for quality assurance and
radiation hardness evaluation.
These test structure diodes are currently used in four irradiation and annealing
campaigns, addressing and going beyond CMS HGCAL radiation hardness
qualification needs.
Neutron irradiation campaigns covering both a low fluence range from 1e13 to
2e14 neq/cm2 and a high fluences range from 2e15 to 1.5e16 neq/cm2 allow to
investigate a broad parameter space regarding radiation damage and annealing
behaviour at up to five different temperatures (6.5 °C to 60 °C).
To simulate a more realistic operational scenario, one set of diodes was irradiated to
fluences ranging from 5e14 to 4e15 neq/cm2 and subsequently annealed at three
different temperatures within the expected beneficial annealing window. In a second
step, these diodes will be further irradiated to end-of-lifetime fluences, consistent
with those studied in the high-fluence campaign.
Additionally, a subset of diodes was irradiated with protons (2e15–8e15 neq/cm2),
and long-term annealing studies at 20 °C , 40 °C and 60 °C were started in order to
specifically investigate potential differences in the annealing behaviour depending on
the impact particles.
This talk will present initial results from the low fluence, double irradiation, and proton
campaigns, covering observed beneficial annealing effects. Advanced results from
the high fluence campaign will be shown in a separate talk by Leena Diehl.
| Type of presentation (in-person/online) | in-person presentation |
|---|---|
| Type of presentation (I. scientific results or II. project proposal) | I. Presentation on scientific results |
