Enhancement of Coherent X ray Diffraction from Nanocrystals by Introduction of X ray Optics

Coherent X-ray Diffraction is applied to investigate the structure of individual nanocrystalline silver particles in the 100nm size range. In order to enhance the available signal, Kirkpatrick-Baez focusing optics have been introduced in the 34-ID-C beamline at APS. Concerns about the preservation of coherence under these circumstances are addressed through experiment and by calculations

The Nineteenth Century Apostolic Christian Church: The Emergence, Establishment, and Fragmentation of a Neo-Anabaptist Sect

This article traces the emergence, proliferation, and identity formation of a 19th century Neo-Anabaptist sect known variously as Neutäufer (New Anabaptists), Nazarenes, and Apostolic Christian Church. The Neutäufer emerged during an era that was a turning point in world religious history, marked by a renewed sense of missionary vigor and the proliferation of major voluntary (as opposed to state-driven) religious movements. These movements radically transformed Western, and even global, Christianity. The article gives detailed attention to the role of Samuel Heinrich Fröhlich in synthesizing evangelical renewalist impulses with traditional Anabaptist convictions. It also follows the tensions that emerged, where agreed upon centrally held traditional Anabaptist values—e.g. non-conformity, plainness, and separation from the world—came to be understood differently as the movement diversified beyond its original context. This article not only contributes to the historical study of the Neutäufer but also contributes to understanding the sociological dynamics of the emergence, establishment, and fragmentation of religious sectarian movements more generally

Nuclear Structure Studies at ISOLDE and their Impact on the Astrophysical r-Process

The focus of the present review is the production of the heaviest elements in nature via the r-process. A correct understanding and modeling requires the knowledge of nuclear properties far from stability and a detailed prescription of the astrophysical environment. Experiments at CERN/ISOLDE have played a pioneering role in exploring the characteristics of nuclear structure in terms of masses and beta-decay properties. Initial examinations paid attention to far unstable nuclei with magic neutron numbers related to r-process peaks, while present activities are centered on the evolution of shell effects with the distance from the valley of stability. We first show in site-independent applications the effect of both types of nuclear properties on r-process abundances. Then, we explore the results of calculations related to two different `realistic' astrophysical sites, (i) the supernova neutrino wind and (ii) neutron star mergers. We close with a list of remaining theoretical and experimental challenges needed to overcome for a full understanding of the nature of the r-process, and the role CERN/ISOLDE can play in this process.Comment: LATEX, 38 pages, 16 figures, submitted to Hyperfine Interaction

Fine Structure of the Radial Breathing Mode in Double-Wall Carbon Nanotubes

The analysis of the Raman scattering cross section of the radial breathing modes of double-wall carbon nanotubes allowed to determine the optical transitions of the inner tubes. The Raman lines are found to cluster into species with similar resonance behavior. The lowest components of the clusters correspond well to SDS wrapped HiPco tubes. Each cluster represents one particular inner tube inside different outer tubes and each member of the clusters represents one well defined pair of inner and outer tubes. The number of components in one cluster increases with decreasing of the inner tube diameter and can be as high as 14.Comment: 5 pages, 3 figure

Critical properties of loop percolation models with optimization constraints

We study loop percolation models in two and in three space dimensions, in which configurations of occupied bonds are forced to form closed loop. We show that the uncorrelated occupation of elementary plaquettes of the square and the simple cubic lattice by elementary loops leads to a percolation transition that is in the same universality class as the conventional bond percolation. In contrast to this an optimization constraint for the loop configurations, which then have to minimize a particular generic energy function, leads to a percolation transition that constitutes a new universality class, for which we report the critical exponents. Implication for the physics of solid-on-solid and vortex glass models are discussed.Comment: 8 pages, 8 figure

Full-field structured-illumination super-resolution X-ray transmission microscopy

Modern transmission X-ray microscopy techniques provide very high resolution at low and medium X-ray energies, but suffer from a limited field-of-view. If sub-micrometre resolution is desired, their field-of-view is typically limited to less than one millimetre. Although the field-of-view increases through combining multiple images from adjacent regions of the specimen, so does the required data acquisition time. Here, we present a method for fast full-field super-resolution transmission microscopy by structured illumination of the specimen. This technique is well-suited even for hard X-ray energies above 30 keV, where efficient optics are hard to obtain. Accordingly, investigation of optically thick specimen becomes possible with our method combining a wide field-of-view spanning multiple millimetres, or even centimetres, with sub-micron resolution and hard X-ray energies