Diffusion based degradation mechanisms in giant magnetoresistive spin valves

Spin valve systems based on the giant magnetoresistive (GMR) effect as used for example in hard disks and automotive applications consist of several functional metallic thin film layers. We have identified by secondary ion mass spectrometry (SIMS) two main degradation mechanisms: One is related to oxygen diffusion through a protective cap layer, and the other one is interdiffusion directly at the functional layers of the GMR stack. By choosing a suitable material as cap layer (TaN), the oxidation effect can be suppressed.Comment: 3 pages, 3 figures. to be published in Appl. Phys. Let

DIRAC framework evaluation for the Fermi\boldsymbol{Fermi}-LAT and CTA experiments

DIRAC (Distributed Infrastructure with Remote Agent Control) is a general framework for the management of tasks over distributed heterogeneous computing environments. It has been originally developed to support the production activities of the LHCb (Large Hadron Collider Beauty) experiment and today is extensively used by several particle physics and biology communities. Current ($Fermi$ Large Area Telescope -- LAT) and planned (Cherenkov Telescope Array -- CTA) new generation astrophysical/cosmological experiments, with very large processing and storage needs, are currently investigating the usability of DIRAC in this context. Each of these use cases has some peculiarities: $Fermi$-LAT will interface DIRAC to its own workflow system to allow the access to the grid resources, while CTA is using DIRAC as workflow management system for Monte Carlo production and analysis on the grid. We describe the prototype effort that we lead toward deploying a DIRAC solution for some aspects of $Fermi$-LAT and CTA needs.Comment: proceedings to CHEP 2013 conference : http://www.chep2013.org

Individual Sanctions for Competition Law Infringements: Pros, Cons and Challenges

Following the substantive harmonization in Regulation (EC) no. 1/2003, the European Commission has started more recently to focus on the harmonization of procedure and sanctions, and in January 2016, the European Parliament called for penalties against natural persons. This special issue looks at the current state of individual sanctions on the EU Member State level, examines from a comparative perspective the institutional challenges which these individual sanctions present, especially for leniency programmes, and discusses the pros and cons of introducing further individual, in particular criminal sanctions in Europe. It examines the experience with criminal sanctions in France, Germany, the United Kingdom and the United States, and presents empirical evidence on public attitudes towards competition law infringements in various Member States and the United States

Influence of wavelength and accumulated fluence at picosecond laser-induced surface roughening of copper on secondary electron yield

Ultrashort-pulse laser processing of copper is performed in air to reduce the secondary electron yield (SEY). By UV (355 nm), green (532 nm), and IR (1064 nm) laser-light induced surface modification, this study investigates the influence of the most relevant experimental parameters, such as laser power, scanning speed, and scanning line distance (represented as accumulated fluence) on the ablation depth, surface oxidation, topography, and ultimately on the SEY. Increasing the accumulated laser fluence results in a gradual change from a Cu 2 O to a CuO-dominated surface with deeper micrometer trenches, higher density of redeposited surface particles from the plasma phase, and a reduced SEY. While the surface modifications are less pronounced for IR radiation at low accumulated fluence (,1000 J/cm2 ), analogous results are obtained for all wavelengths when reaching the nonlinear absorption regime, for which the SEY maximum converges to 0.7. Furthermore, independent of the extent of the structural transformations, an electron-induced surface conditioning at 250 eV allows a reduction of the SEY maximum below unity at doses of 5×10 -4 C/mm2 . Consequently, optimization of processing parameters for application in particle accelerators can be obtained for a sufficiently low SEY at controlled ablation depth and surface particle density, which are factors that limit the surface impedance and the applicability of the material processing for ultrahigh vacuum systems. The relations between pro- cessing parameters and surface features will provide guidance in treating the surface of vacuum components, especially beam screens of selected magnets of the Large Hadron Collider or of future colliders

The Puzzle of Neutron Lifetime

In this paper we review the role of the neutron lifetime and discuss the present status of measurements. In view of the large discrepancy observed by the two most precise individual measurements so far we describe the different techniques and point out principle strengths and weaknesses. In particular we discuss the estimation of systematic uncertainties and its correlation to the statistical ones. In order to solve the present puzzle, many new experiments are either ongoing or being proposed. An overview on their possible contribution to this field will be given.Comment: 10 pages, 19 figures, Proceedings of the International Workshop on Particle Physics with Slow Neutron