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Scientific Report 2007-2009
Laboratories and Facilities of the Department of Physics
L19. Laboratory of the KLOE-ROMA group
The group of the Physics Department participates to the KLOE experiment at the DAΦNE e + e − collider of the Frascati
Laboratories of INFN since 1992.
Recently the group has been involved in the intense activity
for the KLOE-2 experiment, which will start its data taking data
in 2010 with an upgraded detector. One of the main improvements
is a small angle electron and positron tagger, made by a
pair of compact calorimeters, called low energy taggers (LET).
These calorimeters are made of LYSO scintillating crystals and
read-out by silicon photomultipliers, and the Roma group has
the responsability of their design, construction, installation and
test. Among the several activities, it can be mentioned the test
of the scintillating properties of the LYSO crystals performed inside
a black box with a small 137 Cs source with the experimental
set-up shown in Fig.1. The same set-up using a LED as a light
source has been used to test the performance of the silicon photomultipliers,
and also of other kinds of photodetectors (e.g. high
quantum efficiency photomultipliers for a preliminary study of Figure 1: The experimental set-up for the test of scintillating
crystals and photodetectors.
the KLOE upgrade.)
Another activity of the group focused on the study of the response
of the lead-scitillating fiber calorimeters to neutrons of
kinetic energy in the range between 20 and 180 MeV. A prototype calorimeter realized in the Roma Laboratory has been
successfully tested at the neutron beam of the TSL Laboratory of the Uppsala University (Sweden), showing an enhanced
detection efficiency with respect to equivalent bulk scintillator counters.
http://www.roma1.infn.it/exp/kloe/
Related research activities: P19, P20, P21.
L20. The ATLAS-KLOE-DREAM laboratory
The laboratory has been used in the past to prepare and test detectors for the particle physics experiment KLOE at the
e+e- collider DAPHNE of the INFN Laboratori Nazionali di Frascati and for the experiment ATLAS at the LHC accelerator
at CERN. In the next future some tests will be performed for the DREAM Collaboration studying a new approach (dual
read out) to optimize hadronic calorimetry in high energy experiments.
For the KLOE experiment in the laboratory has been prepared a small prototype of the big central chamber
before moving that in a test beam at CERN, where a full test of
this drift chamber, operated with a helium - isobuthane mixture,
has been performed also in a magnetic field. This small detector
served also to study the final configuration of the wires in the
chamber of the KLOE detector. For ATLAS in the laboratory
has been prepared and operated the system used to test about
15000 drift tubes before they were assembled in the chambers,
built in Rome, for muon detection in the big spectrometer of
the experiment. The system is visible in the figure. For each
tube the mechanical wire tension and the leakage current in
HV (3080 V for a 4 × 10 4 gain at the wire) were measured. An
accurate system checked the wire off-centerig in the tube with a
10 microns rms in projection. Also the gas leak of the tubes was
measured (gas leaks smaller than 10 −8 bar liter/s at 3 absolute
Figure 2: The system for the test of the drift tubes for
bars were required). All these tests were controlled by a computer.
A non invasive technique to replace broken wires in drift
the muon chambers of ATLAS.
tubes glued in the chambers was then developed in this laboratory and used in other laboratories of the ATLAS Collaboration.
Related research activities: P1, P2, P3, P19, P20, P21.
Sapienza Università di Roma 190 Dipartimento di Fisica