PT Journal
AU ATLAS Collaboration (Aad, Gea
   Amoros, G
   Cabrera Urban, S
   Campabadal Segura, F
   Castillo Gimenez, V
   Costa, MJ
   Escobar, C
   Fassi, F
   Ferrer, A
   Fuster, J
   Garcia, C
   Gonzalez de la Hoz, S
   Hernandez Jimenez, Y
   Higon-Rodriguez, E
   Irles Quiles, A
   Kaci, M
   Lacasta, C
   Lacuesta, VR
   Marti-Garcia, S
   Miñano, M
   Mitsou, VA
   Moles-Valls, R
   Moreno Llacer, M
   Oliver Garcia, E
   Perez Garcia-Estañ, MT
   Ros, E
   Salt, J
   Sanchis-Lozano, MA
   Solans, CA
   Sospedra Suay, L
   Sanchez, J
   Torro Pastor, E
   Valladolid Gallego, E
   Valls Ferrer, JA
   Villaplana Perez, M
   Vos, M
   Wildauer, A
TI Drift Time Measurement in the ATLAS Liquid Argon Electromagnetic Calorimeter using Cosmic Muons
SO European Physical Journal C
JI Eur. Phys. J. C
PY 2010
BP 755
EP 785
VL 70
IS 3
DI 10.1140/epjc/s10052-010-1403-6
LA English
AB The ionization signals in the liquid argon of the ATLAS electromagnetic calorimeter are studied in detail using cosmic muons. In particular, the drift time of the ionization electrons is measured and used to assess the intrinsic uniformity of the calorimeter gaps and estimate its impact on the constant term of the energy resolution. The drift times of electrons in the cells of the second layer of the calorimeter are uniform at the level of 1.3% in the barrel and 2.8% in the endcaps. This leads to an estimated contribution to the constant term of (0.29(-0.04)(+0.05))% in the barrel and (0.54(-0.04)(+0.06))% in the endcaps. The same data are used to measure the drift velocity of ionization electrons in liquid argon, which is found to be 4.61 +/- 0.07 mm/mu s at 88.5 K and 1 kV/mm.
ER