Radiation hardness of the LHCb Outer Tracker van Eijk, D.; Bachmann, S.; Bauer, Th ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
09/2012, Letnik:
685
Journal Article
Recenzirano
Odprti dostop
This paper presents results on the radiation hardness of the LHCb Outer Tracker (OT) during LHC operation in 2010 and 2011. Modules of the OT have shown to suffer from ageing effects that lead to ...gain loss, after irradiation in the laboratory. Under irradiation at moderate intensities an insulating layer is formed on the anode wire of the OT straw cells. This ageing effect is caused by contamination of the counting gas due to outgassing of the glue used in the construction of the OT modules. Two methods to monitor gain stability in the OT are presented: module scans with radioactive sources and the study of hit efficiency as a function of amplifier threshold. No gain loss is observed after receiving 1.3fb−1 of integrated luminosity corresponding to an integrated charge of 0.055C/cm in the hottest spot of the detector.
Ageing in the LHCb outer tracker: Aromatic hydrocarbons and wire cleaning Tuning, N.; Bachmann, S.; Bagaturia, Y. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
11/2011, Letnik:
656, Številka:
1
Journal Article
Recenzirano
The LHCb Outer Tracker straw tubes have shown to suffer from gain loss after irradiation in the laboratory at moderate intensities. Under irradiation an insulating layer is formed on the anode wire. ...The ageing is caused by contamination of the counting gas due to outgassing of the plastifier di-isopropyl-naphthalene in araldite AY103-1 used at construction. This paper presents irradiation results with and without the plastifier, together with the mass spectra of the glue samples. In addition, the effects of wire heating and large currents are presented.
The LHCb Outer Tracker (OT) detector has shown to suffer from gain loss after irradiation in the laboratory at moderate intensities. Under irradiation an insulating layer is formed on the anode wire. ...The ageing is caused by contamination of the counting gas due to outgassing of the glue used in construction namely araldite AY103-1. The gain loss is concentrated upstream the gas flow, and at moderate irradiation intensity only. The ageing rate is reduced by longterm flushing and by the addition of a few percent of
O
2
to the gas mixture. Furthermore, applying a large positive high voltage (beyond the amplification regime) removes the insulating deposits without damaging the wire surface. This paper presents both the characteristics of the ageing phenomenon and the beneficial treatments.
The straw tube technology for the LHCb outer tracking system Bachmann, S.; Bagaturia, I.; Deppe, H. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
12/2004, Letnik:
535, Številka:
1
Journal Article
Recenzirano
Odprti dostop
For the outer tracking system of the LHCb spectrometer 53.760 straws of 2.5
m length will be used. They are arranged in detector modules of 5
m length and 0.34
m width. The envisaged spatial ...resolution over the entire active area is 200
μ
m resulting in stringent requirements on the accuracy for the module construction.
In this paper we discuss the optimisation of the straws, design and construction of detector modules. The long-term operation properties of straws in two different counting gases, Ar/CO
2
(70/30) and Ar/CO
2
/CF
4
(75/10/15), are compared.
Universal mass dependence for meson and baryon inclusive cross-sections advocated recently in
e
+
e
− annihilation and in hadronic reactions is shown to be consistent also with heavy ion collisions ...data. We propose to use this dependence as a reference for quark-gluon plasma studies.
The hadronic part of the electron structure function F2e has been measured for the first time, using e+e− data collected by the DELPHI experiment at LEP, at centre-of-mass energies of ...s=91.2–209.5 GeV. The data analysis is simpler than that of the measurement of the photon structure function. The electron structure function F2e data are compared to predictions of phenomenological models based on the photon structure function. It is shown that the contribution of large target photon virtualities is significant. The data presented can serve as a cross-check of the photon structure function F2γ analyses and help in refining existing parameterisations.
We show that the data on inclusive cross-sections for light mesons and baryons in high energy hadron-hadron interactions are consistent with a simple empirical formula
σ
incl
= a
(2J + 1)
(2I
m
+ 1)
...exp(−bM
2)
observed recently in e
+e
− annihilations, where
J is the spin,
I
m is a modified isospin and
M is the mass of the produced particle. The same value of the slope parameter
b is observed for e
+e
− annihilations at PEP/PETRA and LEP energies and for proton-proton interactions at ISR energies. This universal dependence points to a simple mass law for hadron states produced locally in string fragmentation irrespective of the configuration of the strings in various processes.
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