Exploring the limits of soft x-ray magnetic holography: Imaging magnetization reversal of buried interfaces (invited)

The following article appeared in Journal of Applied Physics 109.7 (2011): 07D357 and may be found at http://scitation.aip.org/content/aip/journal/jap/109/7/10.1063/1.3567035Only a very few experimental techniques can address the microscopic magnetization reversal behavior of the different magnetic layers in a multilayered system with element selectivity. We present an element-selective study of ferromagnetic (FM) [Co/Pt]n multilayers with perpendicular anisotropy exchange-coupled to antiferromagnetic (AFM) FeMn and IrMn films performed with a new experimental set-up developed for both soft x-ray spectroscopy and holography imaging purposes. The spectroscopy analysis allows the quantification of the unpinned (pinned) uncompensated AFM moments, providing direct evidence of its parallel (antiparallel) alignment with respect to the FM moments. The holography experiments give a direct view of both FM and uncompensated AFM magnetic structures, showing that they replicate to each other during magnetization reversal. Remarkably, we show magnetic images for effective thicknesses as small as one monolayer. Our results provide new microscopic insights into the exchange coupling phenomena and explore the sensitivity limits of these techniques. Future trends are also discussed.We acknowledge technical support by the ESRF staff R. Barrett, R. Homs-Regojo, T. Trenit, and G. Retout. A. B. acknowledges support through a Ramo´n y Cajal contract from the Spanish MICINN. This work was supported in part by the Spanish MICINN through Projects CSD2007-00010, and MAT2010-21822 and by Comunidad de Madrid through Project S2009/MAT-1726.Comunidad de Madrid. S2009/MAT-1726/NANOBIOMAGNE

HIE-ISOLDE SRF development activities at CERN

The HIE-ISOLDE project has initiated a new development phase in the SRF domain at CERN. In particular, the HIE-ISOLDE project aims at the construction of the 32 Quarter Wave Resonators using the Nb on Cu sputtering technology. This paper describes the refurbishment of the test infrastructure and the activities from the cavity production to the cold test, including quality assurance procedure for the correct handling of the resonators

Niobium Coatings for the HIE-ISOLDE QWR Superconducting Accelerating Cavities

The HIE-ISOLDE (High Intensity and Energy at ISOLDE) project is the upgrade of the existing ISOLDE (Isotope Separator On Line DEvice) facility at CERN, which is dedicated to the production of a large variety of radioactive ion beams for nuclear physics experiments. A new linear accelerator made of 20 ȕ=10.3% and 12 ȕ=6.3% quarter-wave resonators (QWR) superconducting (SC) accelerating cavities at 101 MHz will be built, and in a first phase two cryomodules of 5 high-ȕ cavities each are scheduled to accelerate first beams in 2015. The cavities are made of a copper substrate, with a sputter-coated superconductive niobium (Nb) layer, operated at 4.5 K with an accelerating field of 6 MV/m at 10W Radio-Frequency (RF) losses (Q=4.5· 108). In this paper we will discuss the baseline surface treatment and coating procedure which allows obtaining the required performance, as well as the steps undertaken in order to prepare series production of the required number of cavities guaranteeing their quality and functionality

Sensitivity and specificity of different methods for cystic fibrosis-related diabetes screening: is the oral glucose tolerance test still the standard?

International audienc

Effect of abrasive mineral on alloy performance in the ball mill abrasion test

The ball mill abrasion test (BMAT) promises to offer accurate prediction of relative service lives of wear-resistant alloys for liners and grinding media in mineral grinding environments. Relative alloy performance depends strongly on the abrasive minerals present. Towards a greater understanding of factors controlling relative performance, BMAT data have been generated using several pure and blended minerals. The results show that very hard (above 630 HV) martensitic steels and white cast irons only offer large performance benefits when grinding relatively soft or weak abrasives (Mohs hardness less than about 6). This may alter the cost-benefit balance in favour of simple low-cost steels when grinding hard strong minerals, but even modest proportions of softer minerals in real ores can favour the use of more sophisticated hard alloys. Copyright © 2008 Elsevier B.V. All rights reserved

Imaging and quantifying perpendicular exchange biased systems by soft x-ray holography and spectroscopy

International audienc

Status of the Superconducting RF Activities for the HIE ISOLDE Project

The planned upgrade of the REX ISOLDE facility at CERN will boost the energy of the machine from 3 MeV/u up to 10 MeV/u with beams of mass-to-charge ratio 2.5 < A/q < 4. For this purpose, a new superconducting post accelerator based on independently phased 101.28 MHz Quarter Wave Resonators (QWR) will replace part of the normal conducting Linac. The QWRs make use of the Niobium sputtering on Copper technology which was successfully applied to LEP2, LHC and to the energy upgrade of the ALPI Linac at INFNLNL. The status of advancement of the project will be detailed, limited to the SRF activities