Speaker
Till Moritz Karbach
(CERN)
Description
The LHCb experiment is designed to study B-decays at the LHC, and as such is
constructed as a forward spectrometer. The large particle density in the
forward region poses extreme challenges to the subdetectors, in terms of hit
occupancies and radiation tolerance.
To accurately and efficiently detect the charged decay particles in the
high-density particle environment of the LHC the Outer Tracker (OT) has been
constructed. The OT is a gaseous straw tube detector, consisting of 53,760 straw
tubes, covering an area of 360 m2 of double layers.
At the time of the conference, the performance of the OT during run I of the LHC
has been scrutinized. The detector has operated under nominal LHC conditions for
a period of over 2 years, corresponding to an integrated luminosity of
approximately 3 fb-1. A remarkable radiation resistance of this sensitive gas
detector is reported. Unlike most other subdetectors in LHCb, constructed with
various technologies, no sign of ageing is observed after having received a
total dose corresponding to about 100 mC/cm in the hottest region.
Two independent and complementary methods have been used to measure the
radiation resistance of this gas detector in the forward region at the LHC. One
method uses a dedicated setup in situ, with which a 90Sr source is scanned over
the surface of part of the OT detector. The second method utilizes reconstructed
tracks duing LHC operation, with which the hit efficiency over the full detector
surface is determined at increased amplifier threshold.
Primary authors
Niels Tuning
(NIKHEF (NL))
Till Moritz Karbach
(CERN)
