Vanishing lines in generalized Adams spectral sequences are generic

We show that in a generalized Adams spectral sequence, the presence of a vanishing line of fixed slope (at some term of the spectral sequence, with some intercept) is a generic property.Comment: 11 pages. Published copy, also available at http://www.maths.warwick.ac.uk/gt/GTVol3/paper7.abs.htm

New magnetron configurations for sputtered Nb onto Cu

Abstract Niobium sputtered film microstructure and morphology and consequently its superconducting properties, strongly depend on target-substrate deposition angle. In order to improve the Nb film quality for 1.5 GHz cavity coatings, we investigated the application of three main ideas to the sputtering process: (i) making niobium atoms impinging perpendicularly the substrate surface, (ii) promoting the effect of plasma bombardment of the growing film, and (iii) increasing the sputtering rate. Therefore, several different sputtering configurations are under development. The effect of Nb atoms arriving perpendicular to the substrate is explored either by using a cathode that follows the cavity shape or by increasing the plasma confinement efficiency by means of a target parallel to the magnetic field lines. The removal of adsorbed impurities from the film surface and the increase of the film density are investigated by a biased third electrode that promotes the positive ions bombardment of the growing film. A mixed bias-magnetron has been built using a positively charged metal grid positioned all around the cathode

Support varieties for selfinjective algebras

Support varieties for any finite dimensional algebra over a field were introduced by Snashall-Solberg using graded subalgebras of the Hochschild cohomology. We mainly study these varieties for selfinjective algebras under appropriate finite generation hypotheses. Then many of the standard results from the theory of support varieties for finite groups generalize to this situation. In particular, the complexity of the module equals the dimension of its corresponding variety, all closed homogeneous varieties occur as the variety of some module, the variety of an indecomposable module is connected, periodic modules are lines and for symmetric algebras a generalization of Webb's theorem is true