| 1. |
- Aad, G., et al.
(författare)
-
- 2012
-
swepub:Mat__t (refereegranskat)
|
|
| 2. |
|
|
| 3. |
|
|
| 4. |
- Aad, G., et al.
(författare)
-
Readiness of the ATLAS Tile Calorimeter for LHC collisions
- 2010
-
Ingår i: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044 .- 1434-6052. ; 70:4, s. 1193-1236
-
Tidskriftsartikel (refereegranskat)abstract
- The Tile hadronic calorimeter of the ATLAS detector has undergone extensive testing in the experimental hall since its installation in late 2005. The readout, control and calibration systems have been fully operational since 2007 and the detector has successfully collected data from the LHC single beams in 2008 and first collisions in 2009. This paper gives an overview of the Tile Calorimeter performance as measured using random triggers, calibration data, data from cosmic ray muons and single beam data. The detector operation status, noise characteristics and performance of the calibration systems are presented, as well as the validation of the timing and energy calibration carried out with minimum ionising cosmic ray muons data. The calibration systems' precision is well below the design value of 1%. The determination of the global energy scale was performed with an uncertainty of 4%.
|
|
| 5. |
- Aad, G., et al.
(författare)
-
Studies of the performance of the ATLAS detector using cosmic-ray muons
- 2011
-
Ingår i: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044 .- 1434-6052. ; 71:3
-
Tidskriftsartikel (refereegranskat)abstract
- Muons from cosmic-ray interactions in the atmosphere provide a high-statistics source of particles that can be used to study the performance and calibration of the ATLAS detector. Cosmic-ray muons can penetrate to the cavern and deposit energy in all detector subsystems. Such events have played an important role in the commissioning of the detector since the start of the installation phase in 2005 and were particularly important for understanding the detector performance in the time prior to the arrival of the first LHC beams. Global cosmic-ray runs were undertaken in both 2008 and 2009 and these data have been used through to the early phases of collision data-taking as a tool for calibration, alignment and detector monitoring. These large datasets have also been used for detector performance studies, including investigations that rely on the combined performance of different subsystems. This paper presents the results of performance studies related to combined tracking, lepton identification and the reconstruction of jets and missing transverse energy. Results are compared to expectations based on a cosmic-ray event generator and a full simulation of the detector response.
|
|
| 6. |
- Aad, G., et al.
(författare)
-
The ATLAS Inner Detector commissioning and calibration
- 2010
-
Ingår i: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044 .- 1434-6052. ; 70:3, s. 787-821
-
Tidskriftsartikel (refereegranskat)abstract
- The ATLAS Inner Detector is a composite tracking system consisting of silicon pixels, silicon strips and straw tubes in a 2 T magnetic field. Its installation was completed in August 2008 and the detector took part in data-taking with single LHC beams and cosmic rays. The initial detector operation, hardware commissioning and in-situ calibrations are described. Tracking performance has been measured with 7.6 million cosmic-ray events, collected using a tracking trigger and reconstructed with modular pattern-recognition and fitting software. The intrinsic hit efficiency and tracking trigger efficiencies are close to 100%. Lorentz angle measurements for both electrons and holes, specific energy-loss calibration and transition radiation turn-on measurements have been performed. Different alignment techniques have been used to reconstruct the detector geometry. After the initial alignment, a transverse impact parameter resolution of 22.1 +/- 0.9 mu m and a relative momentum resolution sigma (p) /p=(4.83 +/- 0.16)x10(-4) GeV(-1)xp (T) have been measured for high momentum tracks.
|
|
| 7. |
- Aad, G., et al.
(författare)
-
The ATLAS Simulation Infrastructure
- 2010
-
Ingår i: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044 .- 1434-6052. ; 70:3, s. 823-874
-
Tidskriftsartikel (refereegranskat)abstract
- The simulation software for the ATLAS Experiment at the Large Hadron Collider is being used for large-scale production of events on the LHC Computing Grid. This simulation requires many components, from the generators that simulate particle collisions, through packages simulating the response of the various detectors and triggers. All of these components come together under the ATLAS simulation infrastructure. In this paper, that infrastructure is discussed, including that supporting the detector description, interfacing the event generation, and combining the GEANT4 simulation of the response of the individual detectors. Also described are the tools allowing the software validation, performance testing, and the validation of the simulated output against known physics processes.
|
|
| 8. |
- Fowler, D., et al.
(författare)
-
Effects of global change during the 21st century on the nitrogen cycle
- 2015
-
Ingår i: Atmospheric Chemistry and Physics. - : Copernicus GmbH. - 1680-7316 .- 1680-7324. ; 15:24, s. 13849-13893
-
Forskningsöversikt (refereegranskat)abstract
- The global nitrogen (N) cycle at the beginning of the 21st century has been shown to be strongly influenced by the inputs of reactive nitrogen (N-r) from human activities, including combustion-related NOx, industrial and agricultural N fixation, estimated to be 220 TgNyr(-1) in 2010, which is approximately equal to the sum of biological N fixation in unmanaged terrestrial and marine ecosystems. According to current projections, changes in climate and land use during the 21st century will increase both biological and anthropogenic fixation, bringing the total to approximately 600 TgNyr(-1) by around 2100. The fraction contributed directly by human activities is unlikely to increase substantially if increases in nitrogen use efficiency in agriculture are achieved and control measures on combustion-related emissions implemented. Some N-cycling processes emerge as particularly sensitive to climate change. One of the largest responses to climate in the processing of Nr is the emission to the atmosphere of NH3, which is estimated to increase from 65 TgNyr(-1) in 2008 to 93 TgNyr(-1) in 2100 assuming a change in global surface temperature of 5 degrees C in the absence of increased anthropogenic activity. With changes in emissions in response to increased demand for animal products the combined effect would be to increase NH3 emissions to 135 TgNyr(-1). Another major change is the effect of climate changes on aerosol composition and specifically the increased sublimation of NH4NO3 close to the ground to form HNO3 and NH3 in a warmer climate, which deposit more rapidly to terrestrial surfaces than aerosols. Inorganic aerosols over the polluted regions especially in Europe and North America were dominated by (NH4)(2)SO4 in the 1970s to 1980s, and large reductions in emissions of SO2 have removed most of the SO42- from the atmosphere in these regions. Inorganic aerosols from anthropogenic emissions are now dominated by NH4NO3, a volatile aerosol which contributes substantially to PM10 and human health effects globally as well as eutrophication and climate effects. The volatility of NH4NO3 and rapid dry deposition of the vapour phase dissociation products, HNO3 and NH3, is estimated to be reducing the transport distances, deposition footprints and inter-country exchange of N-r in these regions. There have been important policy initiatives on components of the global N cycle. These have been regional or country-based and have delivered substantial reductions of inputs of Nr to sensitive soils, waters and the atmosphere. To date there have been no attempts to develop a global strategy to regulate human inputs to the nitrogen cycle. However, considering the magnitude of global Nr use, potential future increases, and the very large leakage of Nr in many forms to soils, waters and the atmosphere, international action is required. Current legislation will not deliver the scale of reductions globally for recovery from the effects of Nr deposition on sensitive ecosystems, or a decline in N2O emissions to the global atmosphere. Such changes would require substantial improvements in nitrogen use efficiency across the global economy combined with optimization of transport and food consumption patterns. This would allow reductions in Nr use, inputs to the atmosphere and deposition to sensitive ecosystems. Such changes would offer substantial economic and environmental co-benefits which could help motivate the necessary actions.
|
|
| 9. |
- Aad, G., et al.
(författare)
-
- 2011
-
swepub:Mat__t (refereegranskat)
|
|
| 10. |
- Aad, G., et al.
(författare)
-
- 2011
-
Tidskriftsartikel (refereegranskat)
|
|
| 11. |
- Aad, G., et al.
(författare)
-
- 2012
-
swepub:Mat__t (refereegranskat)
|
|
| 12. |
- Aad, G., et al.
(författare)
-
- 2011
-
swepub:Mat__t (refereegranskat)
|
|
| 13. |
- Aad, G., et al.
(författare)
-
- 2013
-
swepub:Mat__t (refereegranskat)
|
|
| 14. |
- Aad, G., et al.
(författare)
-
- 2012
-
swepub:Mat__t (refereegranskat)
|
|
| 15. |
- Aad, G., et al.
(författare)
-
- 2012
-
swepub:Mat__t (refereegranskat)
|
|
| 16. |
- Aad, G., et al.
(författare)
-
- 2012
-
swepub:Mat__t (refereegranskat)
|
|
| 17. |
- Aad, G., et al.
(författare)
-
- 2012
-
swepub:Mat__t (refereegranskat)
|
|
| 18. |
- Aad, G., et al.
(författare)
-
- 2012
-
swepub:Mat__t (refereegranskat)
|
|
| 19. |
- Aad, G., et al.
(författare)
-
- 2012
-
swepub:Mat__t (refereegranskat)
|
|
| 20. |
- Aad, G., et al.
(författare)
-
- 2012
-
swepub:Mat__t (refereegranskat)
|
|
| 21. |
- Aad, G., et al.
(författare)
-
- 2011
-
swepub:Mat__t (refereegranskat)
|
|
| 22. |
- Aad, G., et al.
(författare)
-
- 2011
-
swepub:Mat__t (refereegranskat)
|
|
| 23. |
- Aad, G., et al.
(författare)
-
- 2011
-
swepub:Mat__t (refereegranskat)
|
|
| 24. |
- Aad, G., et al.
(författare)
-
- 2011
-
swepub:Mat__t (refereegranskat)
|
|
| 25. |
- Aad, G., et al.
(författare)
-
- 2012
-
swepub:Mat__t (refereegranskat)
|
|
