The performance of muon reconstruction, identification, and triggering in CMS has been studied using 40 pb −1 of data collected in pp collisions at √ s = 7 TeV at the LHC in 2010. A few benchmark sets of selection criteria covering a wide range of physics analysis needs have been examined. For all considered selections, the efficiency to reconstruct and identify a muon with a transverse momentum p T larger than a few GeV/c is above 95% over the whole region of pseudorapidity covered by the CMS muon system, |η| < 2.4, while the probability to misidentify a hadron as a muon is well below 1%. The efficiency to trigger on single muons with p T above a few GeV/c is higher than 90% over the full η range, and typically substantially better. The overall momentum scale is measured to a precision of 0.2% with muons from Z decays. The transverse momentum resolution varies from 1% to 6% depending on pseudorapidity for muons with p T below 100 GeV/c and, using cosmic rays, it is shown to be better than 10% in the central region up to p T = 1 TeV/c. Observed distributions of all quantities are well reproduced by the Monte Carlo simulation.

We have investigated Al adsorption on the W(100) surface using LEED and low energy Ion Scattering Spectroscopy (ISS). We observe a p(2 × 1) double domain LEED image for the 1.0 ML Al/W(100) surface at annealing temperature 850 • C. We also measured the Al adsorption site at the Al/W(100) -p(2 × 1) surface using ISS. It is found that Al atoms adsorbed at 0.7 ± 0.1Å aside from the center of the bridge sites with a zigzag structure -one atom adsorbs at the right-hand side and next atom at the left-hand side along the [100] direction. The height of the adsorbed Al atoms is determined to be 1.75 ± 0.15Å above the W surface layer. Keywords: Low energy ion scattering; W(100); Al; surface structure; adsorption site. 835 Mod. Phys. Lett. B 2009.23:835-847. Downloaded from www.worldscientific.com by UNIVERSITY OF CALIFORNIA @ DAVIS on 02/08/15. For personal use only.

BaM (barium ferrite) thin films and underlayers (Fe, Cr, Al2O3, Fe2O3, ZnFe2O4, TiO2) were prepared by rf/dc magnetron sputtering on (100) oriented bare Si substrates. The effects of the underlayer on grain orientation, magnetic properties, and microtexture of BaM film were studied. All the BaM films, except BaM/Fe/Si film, attained nearly the same perpendicular and in-plane coercivities. The BaM/TiO2/Si exhibits the highest coercivity. However, regardless of the underlayer, BaM grains are randomly oriented. By adopting ZnFe2O4 as an underlayer, the interdiffusion of Si from substrate was prohibited to some degree. Elongated grains from the extinction of small platelet grains were grown with an increase in the BaM film thickness of BaM/Si. The microstructure of BaM in BaM/TiO2/Si was strongly dependent on both the microstructure of TiO2 underlayer and the total sputtering gas pressure.

The surface structure of Ag/W(100) has been studied using LEED and Low Energy Ion Scattering Spectroscopy (ISS). We find that Ag coverages are saturated at 0.5 ML after annealing at 800°C regardless of the initial coverages between 0.7~1.0 ML. We observe a c(2×2) image after annealing the Ag/W(100) sample at 800°C. Using the ISS technique the adsorption site of Ag on the c(2×2) surface is found to be the center of the nearest two atoms on the W(100) surface. The height of the Ag adsorption layer is 1.58 Å above the W(100) surface.

The growth mode of Ag atoms on the W (110) plane has been studied using LEED and Low Energy Ion Scattering Spectroscopy (ISS). We find that Ag atoms grow in SK mode after annealing at 700°C for the coverage ~ 3.0 ML. The grown three-dimensional Ag islands have the (111) plane surface. The [Formula: see text] direction of the Ag islands is rotated 4.4° from (001) direction of the W (110) surface. Using the ISS technique the surface structure of the two-dimensional Ag islands is investigated. The Ag adsorption height measured from the first layer of the W (110) surface is found to be 2.79 Å.