Alignment of the Pixel and SCT Modules for the 2004 ATLAS Combined Test Beam

A small set of final prototypes of the ATLAS Inner Detector silicon tracker (Pixel and SCT) were used to take data during the 2004 Combined Test Beam. Data were collected from runs with beams of different flavour (electrons, pions, muons and photons) with a momentum range of 2 to 180 GeV/c. Four independent methods were used to align the silicon modules. The corrections obtained were validated using the known momenta of the beam particles and were shown to yield consistent results among the different alignment approaches. From the residual distributions, it is concluded that the precision attained in the alignment of the silicon modules is of the order of 5 micrometers in their most precise coordinate.Comment: 22 pages, submitted to JINST, 129 author

New method to extract the neutron-electron scattering length

A novel method to extract the neutron-electron scattering length b ne from the precise neutron scattering data measured for a noble gas at several different densities n is proposed. The main point of this method is dividing the experimental data into two parts: the first, nearly proportional to n, corresponding to diffraction on neighboring atoms and the second one, a small contribution of n, e scattering independent on n. The proposed technique is demonstrated using the structure factor S(q) for gaseous krypton