- The ATLAS Collaboration
- Aad, G
- Abbott, B
- Abdallah, J
- Abdelalim, AA
- Abdesselam, A
- Abdinov, O
- Abi, B
- Abolins, M
- Abramowicz, H
- Abreu, H
- Acharya, BS
- Adams, DL
- Addy, TN
- Adelman, J
- Adorisio, C
- Adragna, P
- Adye, T
- Aefsky, S
- Aguilar-Saavedra, JA
- Aharrouche, M
- Ahlen, SP
- Ahles, F
- Ahmad, A
- Ahsan, M
- Aielli, G
- Akdogan, T
- Åkesson, TPA
- Akimoto, G
- Akimov, AV
- Aktas, A
- Alam, MS
- Alam, MA
- Albrand, S
- Aleksa, M
- Aleksandrov, IN
- Alexa, C
- Alexander, G
- Alexandre, G
- Alexopoulos, T
- Alhroob, M
- Aliev, M
- Alimonti, G
- Alison, J
- Aliyev, M
- Allport, PP
- Allwood-Spiers, SE
- Almond, J
- Aloisio, A
- Alon, R
- Alonso, A
- Alviggi, MG
- Amako, K
- Amelung, C
- Amorim, A
- Amorós, G
- Amram, N
- Anastopoulos, C
- Andeen, T
- Anders, CF
- Anderson, KJ
- Andreazza, A
- Andrei, V
- Anduaga, XS
- Angerami, A
- Anghinolfi, F
- Anjos, N
- Annovi, A
- Antonaki, A
- Antonelli, M
- Antonelli, S
- Antos, J
- Antunovic, B
- Anulli, F
- Aoun, S
- Arabidze, G
- Aracena, I
- Arai, Y
- Arce, ATH
- Archambault, JP
- Arfaoui, S
- Arguin, JF
- Argyropoulos, T
- Arik, M
- Armbruster, AJ
- Arnaez, O
- Arnault, C
- Artamonov, A
- Arutinov, D
- Asai, M
- Asai, S
- Asfandiyarov, R
- Ask, S
- Åsman, B
- Asner, D
- Asquith, L
- Assamagan, K
- Astvatsatourov, A
- Atoian, G
- Auerbach, B
- et al.
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 μm and a relative momentum resolution σp/p=(4. 83±0. 16)×10-4 GeV-1×pT have been measured for high momentum tracks. © 2010 CERN for the benefit of the ATLAS collaboration.