Author:
Aehle M.,Alme J.,Arata C.,Arsene I.,Bearden I.,Bodova T.,Borshchov V.,Bourrion O.,Bregant M.,van den Brink A.,Buchakchiev V.,Buhl A.,Chujo T.,Dufke L.,Eikeland V.,Fasel M.,Gauger N.,Gautam A.,Ghimouz A.,Goto Y.,Guernane R.,Hachiya T.,Hassan H.,He L.,Helstrup H.,Huhta L.,Inaba M.,Inukai T.,Isidori T.,Jonas F.,Kawaguchi T.,Keidel R.,Kim M.H.,Kozhuharov V.,Kumaoka T.,Kusch L.,Loizides C.,Melikyan Y.,Miake Y.,Minafra N.,Nystrand J.,Novitzky N.,Økland T.,Oyama K.,Park H.,Park J.,Pascal I.,Peitzmann T.,Protsenko M.,Räsänen S.S.,Rarbi F.,Rauch M.,Rehman A.,Richter M.,Röhrich D.,Røed K.,Rusu A.,Rytkönen H.,Sakai S.,Sato K.,Schilling A.,Shimizu S.,Shimomura M.,Simeonov R.,Solheim E.,Sugitate T.,Tambave G.,Tapia Takaki D.,Tourres D.,Tymchuk I.,Yi J.,Yin Z.,Ullaland K.,Yang S.,Yokoo T.,Zhou D.,Zillien S.
Abstract
Abstract
We present the performance of a full-length prototype of the
ALICE Forward Calorimeter (FoCal). The detector is composed of a
silicon-tungsten electromagnetic sampling calorimeter with
longitudinal and transverse segmentation (FoCal-E) of about 20X
0
and a hadronic copper-scintillating-fiber calorimeter (FoCal-H) of
about 5λ
int. The data were taken in various test
beam campaigns between 2021 and 2023 at the CERN PS and SPS beam
lines with hadron beams up to energies of 350 GeV, and electron
beams up to 300 GeV. Regarding FoCal-E, we report a
comprehensive analysis of its response to minimum ionizing particles
across all pad layers, employing various operational modes including
different pre-amplifier and bias voltage settings. The longitudinal
shower profile of electromagnetic showers is measured with a
layer-wise segmentation of 1X
0. As a projection to the
performance of the final detector in electromagnetic showers, we
demonstrate linearity in the full energy range, and show that the
energy resolution fulfills the requirements for the physics needs.
Additionally, the performance to separate two-showers events was
studied by quantifying the transverse shower width. Regarding
FoCal-H, we report a detailed analysis of the response to hadron
beams between 60 and 350 GeV. The results are compared to
simulations obtained with a Geant4 model of the test beam
setup, which in particular for FoCal-E are in good agreement with
the data. The energy resolution of FoCal-E was found to be lower
than 3% at energies larger than 100 GeV. The response of
FoCal-H to hadron beams was found to be linear, albeit with a
significant intercept that is about factor 2 larger than in
simulations. Its resolution, which is non-Gaussian and generally
larger than in simulations, was quantified using the FWHM, and
decreases from about 16% at 100 GeV to about 11% at 350 GeV.
The discrepancy to simulations, which is particularly evident at low
hadron energies, needs to be further investigated.
Reference41 articles.
1. Letter of Intent: A Forward Calorimeter (FoCal) in the ALICE experiment;ALICE Collaboration,2020
2. The ALICE experiment at the CERN LHC;ALICE Collaboration;JINST,2008
3. Physics of the ALICE Forward Calorimeter upgrade;ALICE Collaboration,2023
4. Physics performance of the ALICE Forward Calorimeter upgrade;ALICE Collaboration,2023
5. The FoCal prototype—an extremely fine-grained electromagnetic calorimeter using CMOS pixel sensors;de Haas;JINST,2018