Muon capture in the front end of the IDS neutrino factory

We discuss the design of the muon capture front end of the neutrino factory International Design Study. In the front end, a proton bunch on a target creates secondary pions that drift into a capture transport channel, decaying into muons. A sequence of rf cavities forms the resulting muon beams into strings of bunches of differing energies, aligns the bunches to (nearly) equal central energies, and initiates ionization cooling. The muons are then accelerated to high energy where their decays provide neutrino beams. For the International Design Study (IDS), a baseline design must be developed and optimized for an engineering and cost study. We present a baseline design that can be used to establish the scope of a future neutrino Factory facility.Comment: 3 pp. 1st International Particle Accelerator Conference: IPAC'10, 23-28 May 2010: Kyoto, Japa

The Crackle of Contemporaneity

There comes a time to move beyond asking the broad question “What is contemporaneity?” to consider more acute ways in which this question can be traced and signalled. We consider the notion of signal to be particularly appropriate in the consideration of contemporaneity, since signals are a constitutive element of contemporary infrastructures and our experience of time even if they are relatively undetectable. They operate underneath human perceptual thresholds as carriers, controllers, and codes, while also surfacing into perceptual and semiotic registers, as signs across various media—textual, visual, and, of course, sonic—all the while accessible as traces. Perhaps in this way it is possible to experience contemporaneity at a range of different scales— from the microtemporal to the planetary—to register both our closeness and distance from it (Agamben 2009), and to exemplify how times come together disjunctively in the present

Social capital, local communities and culture-led urban regeneration processes: the Sydney Olympic Park experience

Culture has become increasingly important in regeneration processes designed to deal with urban futures. Urban regeneration processes in which culture has played a prominent role range from large-scale public investments in cultural facilities and artefacts as `hallmarks of urban regeneration projects (e.g. Guggenheim Bilbao), through to the use of `one shot cultural events such as the Olympic Games as a catalyst and engine for regenerating urban areas. The aim of this paper is to examine the association between social capital (SC), local communities and the culture-led regeneration process at Sydney Olympic Park (SOP), New South Wales, Australia. The catalyst for the transformation of an industrial wasteland into SOP was the awarding of the Olympics to Sydney in 1993. A convenience sample of 47 professional reports associated with the regeneration process at SOP between 1993 and 2010 were analyzed, the aim being to understand how local communities had been linked to the regeneration process through SC. Results from the analysis identified three principal associations between SC, local communities and the ongoing SOP regeneration process. The first association related to how, during the early years of the regeneration process, SC was used as a means of expressing concern about how governance mechanisms implemented at SOP might adversely impact the ability of local communities to engage in decision making that affected their local environment

Muon Ionisation Cooling in Reduced RF

In Muon Ionisation Cooling, closely packed high-field RF cavities are interspersed with energy-absorbing material in order to reduce particle beam emittance. Transverse focussing of the muon beams is achieved by superconducting magnets. This results in the RF cavities sitting in intense magnetic fields. Recent studies have shown that this may limit the peak gradient that can be achieved in the RF cavities. In this paper, we study the effect that a reduced RF gradient may have on the cooling performance of the Neutrino Factory lattice and examine methods to mitigate the effect

Improved theoretical prediction for the 2s hyperfine interval in helium ion

We consider the uncertainty of theoretical calculations for a specific difference of the hyperfine intervals in the 1s and 2s states in a light hydrogen-like atom. For a number of crucial radiative corrections the result for hydrogen atom and helium ion appears as an extrapolation of the numerical data from medium to low Z. An approach to a plausible estimation of the uncertainty is suggested using the example of the difference $D_{21}= 8E_{hfs}(2s)-E_{hfs}(1s)$

FINITE H-DIMENSION DOES NOT IMPLY EXPRESSIVE COMPLETENESS

Accepted versio

Synthesis and antibacterial effects of cobalt–cellulose magnetic nanocomposites

© The Royal Society of Chemistry. Green synthesis is employed to prepare cobalt/cellulose nanocomposites with cubic (α-cobalt) cobalt as a main component with antibacterial and magnetic properties. An in situ reduction of aqueous solutions of cobalt ions on a model cellulose substrate surface using hydrogen gas affords spherical, cellulose-stabilised cobalt nanoclusters with magnetic properties and an average diameter of 7 nm that are distributed evenly over the surface of the cellulose fibres. These cobalt/cellulose nanocomposites exhibit good antibacterial action against opportunistic pathogens both Gram-positive (S. aureus) and Gram-negative (E. coli, A. baumannii and P. aeruginosa), with zones of inhibition up to 15 mm, thereby encouraging the deployment of these advanced materials for the treatment of wastewater or within medical dressings. This method of preparation is compared with the analogous in situ reduction of cobalt ions on a cellulose surface using sodium borohydride as reducing agent