Production of the ATLAS pixel detector modules Gemme, Claudia
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
05/2006, Letnik:
560, Številka:
1
Journal Article
Recenzirano
The ATLAS experiment will make use of a pixel detector in the innermost part of its semiconductor tracker. The pixel detector consists of three cylindrical layers in the barrel part and three disks ...in the forward and backward parts. Modules are the building blocks of the detector. There are 1456 modules in the barrel and 288 in the end-caps. They are all identical to simplify construction and maintenance. The installation of the pixel detector in the experiment is foreseen early in 2006 and the module production should be finished in the fall of 2005. In this paper the status of the module production is reported, focusing on the problems we have found in this large-scale production.
Small bowel adenocarcinoma is a rare tumor, with a still not well studied tumorigenesis process, usually presenting in an advanced stage. The clinical diagnosis is often difficult; surgery is the ...treatment of choice when feasible, while the chemotherapeutic approach is still not well standardized. We describe the case of a 71-yr-old male patient, presenting with an acute right abdomen. At laparotomy the terminal ileum appeared chronically inflamed and thickened. An ileocecal resection with latero-lateral ileocolic anastomosis was performed. The gross appearance resembled an inflammatory bowel disease, but microscopic examination revealed the extensive presence of an infiltrating ileal adenocarcinoma. Literature about small bowel adenocarcinoma has been reviewed for better understanding its pathogenesis.
Silicon pixel sensors developed by the ATLAS collaboration to meet LHC requirements and to withstand hadronic irradiation to fluences of up to
10
15
n
eq
/
cm
2
have been evaluated using a test beam ...facility at CERN providing a magnetic field. The Lorentz angle was measured and found to alter from 9.0° before irradiation, when the detectors operated at
150
V
bias at
B=1.48
T
, to 3.1° after irradiation and operating at
600
V
bias at
1.01
T
. In addition to the effect due to magnetic field variation, this change is explained by the variation of the electric field inside the detectors arising from the different bias conditions.
The depletion depths of irradiated sensors at various bias voltages were also measured. At
600
V
bias
280
μm
thick sensors depleted to
≈200
μm
after irradiation at the design fluence of
1×10
15
1
MeV
n
eq
/
cm
2
and were almost fully depleted at a fluence of
0.5×10
15
1
MeV
n
eq
/
cm
2
.
The spatial resolution was measured for angles of incidence between 0° and 30°. The optimal value was found to be better than
5.3
μm
before irradiation and
7.4
μm
after irradiation.
The silicon pixel tracking system for the ATLAS experiment at the Large Hadron Collider is described and the performance requirements are summarized. Detailed descriptions of the pixel detector ...electronics and the silicon sensors are given. The design, fabrication, assembly and performance of the pixel detector modules are presented. Data obtained from test beams as well as studies using cosmic rays are also discussed.
Study of indium bumps for the ATLAS pixel detector Gemme, C.; Fiorello, A.M.; Gagliardi, G. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
06/2001, Letnik:
465, Številka:
1
Journal Article
Recenzirano
The bump-bonding technology is used to join the front-end read-out chips to the silicon substrate of the ATLAS pixel detector. We review the current status of the technology used by Alenia Marconi ...Systems and we report on the electrical and mechanical properties and the defect rate of the Indium bumps.
Charmed-meson production by 350 GeV/c π
− particles incident on copper and tungsten targets has been studied in the WA92 experiment, performed at the CERN Ω′ spectrometer. Results obtained are ...reported and discussed. Reconstruction of decays from the set D
0 → K
−
π
+ D
0 → K
−
π
−
π
+
π
+, D
s
+ →
φπ
+ and charge conjugates has yielded a sample of 7280 ± 108 charmed mesons, produced with
χ
F
> 0, (
χ
F
) = 0.18 and〈
p
T
2〉 = 1.86 (
GeV/
c)
2. Assuming a relationship
σ =
σ
0
A
α
between the cross section, σ, per nucleus of mass
A and the nucleonic cross section,
σ
0 the α value found for the detected charmed particles is 0.95 ± 0.06 ± 0.03. Taking
α = 1, the measured cross sections per nucleon for
χ
F
> 0 production are 7.78 ± 0.14 ± 0.52
μb for
D
0/
D
0, 3.28 ± 0.08 ± 0.29 μ
b
for D
+/D
− and 1.29 ± 0.16 ± 0.33
μb for D
s
+/D
s
−. Differential cross sections with respect to
χ
F
and
p
T
2 have been determined for the various types of charmed meson, and particle-antiparticle asymmetries have been analysed.
Effects of Single Event Upsets (SEU) and Single Event Transients (SET) are studied in the FE-I4B chip of the innermost layer of the ATLAS pixel system. SEU/SET affect the FE-I4B Global Registers as ...well as the settings for the individual pixels, causing, among other things, occupancy losses, drops in the low voltage currents, noisy pixels, and silent pixels. Quantitative data analysis and simulations indicate that SET dominate over SEU on the load line of the memory. Operational issues and mitigation techniques are presented.
Electrical characteristics of silicon pixel detectors Gorelov, I; Gorfine, G; Hoeferkamp, M ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
2002, Letnik:
489, Številka:
1
Journal Article
Recenzirano
Prototype sensors for the ATLAS silicon pixel detector have been electrically characterized. The current and voltage characteristics, charge-collection efficiencies, and resolutions have been ...examined. Devices were fabricated on oxygenated and standard detector-grade silicon wafers. Results from prototypes which examine p-stop and standard and moderated p-spray isolation are presented for a variety of geometrical options. Some of the comparisons relate unirradiated sensors with those that have received fluences relevant to LHC operation.
The charge height values associated with PD measured during electrical tree inception and growth are processed according to the Weibull distribution. Test arrangements, based on the needle-plane ...electrode system, consider specimens having either a cavity at the tip or an intimate contact with insulation. It is shown that the Weibull-function parameters have close relation to discharges occurring in cavity and tree channels, and that an indication of inception of electrical trees can be obtained.
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