Speaker
Dr
Alessandro Saputi
(LNF)
Description
The upgrade of the DAFNE machine layout requires a modification of the
size and position of the inner focusing quadrupoles of KLOE-2 thus
asking for the realization of two new calorimeters covering the quadrupoles
area. To improve the reconstruction of $K_L \rightarrow 2 \pi^0$ events with photons hitting the
quadrupoles a calorimeter with high efficiency to low energy photons
(20-300 MeV), time resolution below 1 ns and space resolution of
few cm, is needed. To match these requirements, we are realizing two tile
calorimeters, QCALT, one for each side of IP, where each detector has a
dodecagonal structures, made by a sampling of scintillator tiles and
tungsten, for a total thickness of 5X$_0$.
Each tile is covered with refractive paint and grooved to insert 1 mm round multicladding WLS fibers. Each fiber is readout with 1.2 mm custom
round SiPM bonded on alluminum PCB. During R&D phase we have developed
custom silicon photosensors and a novely soldering and resining technique.
This ensures the required mechanical precision in the coupling between fibers and SiPM. The two QCALTs have a total of around 2000 channels.
The PCB of SIPMs is then connected to FEE cards which provide
bias supply, amplification and discrimination of SiPM signals.
The HV supply has a precision of 0.1% and stability at 0.01% level.
The preamplifier ensure signal stability along time and no deterioration
during transport.
The construction of QCALT is actually in progress with its construction
foreseen for June 2012.
Primary authors
Dr
Alessandro Saputi
(LNF)
Dr
Matteo Martini
(LNF)
