Speaker
Dr
Simona Giovannella
(INFN - LNF)
Description
In the new design of the DAFNE interaction region, the position of the
inner quadrupoles leaves place for inserting a crystal calorimeter to
tag low energy photons in the angular region between 10 and 18 degrees
thus increasing the acceptance of the central calorimeter for rare
eta and kaon decays ( such as $K_s \rightarrow \gamma \gamma$, $\eta \rightarrow \pi^0 \gamma \gamma$,
$K_s \rightarrow 3 \pi^0 $ ...)
The proposed solution is to insert an homogeneous calorimeter immersed
in a 0.52 kG axial magnetic field, CCALT, based on the new generation
of crystals, LYSO, characterized by a very high light yield (60% of
NaI), 40 ns emission time, high density and radiation length.
These crystals match the request for a high efficiency for low energy
photons and an excellent time resolution needed by the calorimeter to
sustain the high level of machine background events. In order to
maximize the light collection and improve its timing performance
we have tested its response both with the fastest Hamamatsu APD
than with large area SIPMs from FBK-IRST.
We have built a prototype matrix of 9 2x2x13 cm$^3$ LYSO crystals read-out
by 10x10 mm$^2$ Hamamatsu avalanche photodiodes (APD) surrounded by
12 PBWO for outer leakage recovery (3 Moliere radius in total)
read-out by bialkali photomultipliers. We have tested it using cosmic
rays, and at electron ( beam test facility of Frascati,2010) and
photon beams (MAMI accelerator facility at Mainz, 2011).
The measurements carried on ad the BTF in Frascati resulted in
a very go
for the collaboration
KLOE-2
Primary author
Dr
Simona Giovannella
(INFN - LNF)
