Survey of the ATLAS Pixel Detector Components

This document provides a description of the survey performed on different components of the ATLAS Pixel Detector at different stages of its assembly

Copper phytoextraction and phytostabilization by Brachiaria decumbens Stapf. in vineyard soils and a copper mining waste.

Brachiaria decumbens is a high biomass plant with great potential for phytoremediation of copper-polluted soils. The current study aimed to evaluate B. decumbens plants for phytoextraction and phytostabilization use in two different copper contaminated vineyard soils and a copper mining waste. Also, the macro and micronutrients uptake were evalu- ated after plants growth in copper contaminated soils. B. decumbens was cultivated in two vineyard soils (Inceptisol and Mollisol) and a copper mining waste for 47 days of growth in greenhouse. Then, B. decumbens?s nutrient uptake was evaluated, and it?s potential application in phytoremediation techniques for the phytoextraction and phytostabilization of copper contamination. B. decumbens exhibited high levels of biomass production at contaminated soils and no negative effect on macronutrients uptake was found. Copper contaminated soils affected micronutrients uptake by Brachiaria plants. This Brachiaria specie showed high potential on copper phytoextraction with accumulation of copper concentra- tions in the shoots and roots of 70 and 585 mg·kg?1 of dry mass, respectively, in the vineyard Inceptisol soil, after 47 days of growth. Mollisol soil and copper mining waste also exhibited high copper concentration in the biomass in the entire plant with 371 and 466 mg·kg?1, respectively. Although Brachiaria exhibited low levels of translocation factor for copper, this specie showed high potential for copper phytoextraction on Inceptisol, Mollisol and copper mining waste with 1900, 1156 and 1363 g·ha?1 of copper, respectively. In summary, B. decumbens plants showed high potential for copper phytoextraction and phytostabilization of copper on contaminated vineyard soils and copper mining waste

Flow phenomena in Atlas

Measurements of flow anisotropy coefficients have been performed with the ATLAS detector at the LHC, on a sample of 8 \u3bcb 121 minimum bias Pb+Pb collisions at centre-of-mass energy 1asNN = 2.76 TeV and a sample of 1 \u3bcb 121 p+Pb collisions at 1asNN = 5.02 TeV. The large statistics Pb+Pb sample is used to derive event-by-event distribution of v2, v3 and v4. Within uncertainties, the distributions of v3 and v4 agree with a pure Gaussian function over a wide centrality range, while significant deviations from this function are observed for v2 in mid- central and peripheral collisions. In the p+Pb sample, a long-range near-side and away-side correlation is observed for events with high transverse energy in the detector. This structure can be described by v2 anisotropy coefficients of magnitude similar to what is observed in Pb+Pb collisions

格式规范

The ATLAS silicon pixel detector is the innermost tracking device of the ATLAS experiment at the Large Hardon Collider, consisting of more than 1700 modules for a total sensitive area of about 1.7 m2 and over 80 million pixel cells. The concept is a hybrid of front-end chips bump bonded to the pixel sensor. The elementary pixel cell has 50 \u3bcm x 400 \u3bcm size, providing pulse height information via the time over threshold technique. Prototype devices with oxygenated silicon sensor and rad-hard electronics built in the IBM 0.25 \u3bcm process have been tested and maintain good resolution, efficiency and timing performances even after receiving the design radiation damage of 1015 neq/cm2

Z boson production in Pb+Pb collisions at √Snn = 5.02 TeV measured by the ATLAS experiment

The production yield of Z bosons is measured in the electron and muon decay channels in Pb+Pb collisions at √S = 5.02 TeV with the ATLAS detector. Data from the 2015 LHC run corresponding to an integrated luminosity of 0.49 nb are used for the analysis. The Z boson yield, normalised by the total number of minimum-bias events and the mean nuclear thickness function, is measured as a function of dilepton rapidity and event centrality. The measurements in Pb+Pb collisions are compared with similar measurements made in proton-proton collisions at the same centre-of-mass energy. The nuclear modification factor is found to be consistent with unity for all centrality intervals. The results are compared with theoretical predictions obtained at next-to-leading order using nucleon and nuclear parton distribution functions. The normalised Z boson yields in Pb+Pb collisions lie 1-3σ above the predictions. The nuclear modification factor measured as a function of rapidity agrees with unity and is consistent with a next-to-leading-order QCD calculation including the isospin effect. nn -