Vibrating Wire for Beam Profile Scanning

The method for measurement of transverse profile (emittance) of the bunch by detecting of radiation arising scattering at of the bunch on the scanning wire is wide-spread. In this work the information about scattering bunch is proposed to measure using the oscillation frequency of the tightened scanning wire. In such way the system of radiation (or secondary particles) extraction and measurement can be removed. Dependence of oscillations frequency on beam scattering is determined by several factors, including changes of wire tension caused by transverse force of the beam, influence of beam self field. Preliminary calculations show that influence caused by wire heating will dominate. We have studied strain gauges on the basis of vibrating wire from various materials (tungsten, beryl bronze, niobium zirconium alloys). A scheme of self oscillations generation by alternating current in autogeneration circuit with automatic frequency adjustment was selected. Special method of wire fixation and elimination of transverse degrees of freedom allow to achieve relative stability better than 1E-5 during several days. For a tungsten wire with a fixed end dependence of frequency on temperature was 1E-5/K. Experimental results and estimates of wire heating of existing scanners show, that the wire heats up to a few hundred grades, which is enough for measurements

Generation of spatial antibunching with free propagating twin beams

We propose and implement a novel method to produce a spatial anti-bunched field with free propagating twin beams from spontaneous parametric down-conversion. The method consists in changing the spatial propagation by manipulating the transverse degrees of freedom through reflections of one of the twin beams. Our method use reflective elements eliminating losses from absorption by the objects inserted in the beams.Comment: Submitted for publication in Phys. Rev.

Control of conditional pattern with polarization entanglement

Conditional interference patterns can be obtained with twin photons from spontaneous parametric down-conversion and the phase of the pattern can be controlled by the relative transverse position of the signal and idler detectors. Using a configuration that produces entangled photons in both polarization and transverse momentum we report on the control of the conditional patterns by acting on the polarization degree of freedom.Comment: Submitted for publication in Optics Communication

Definition and design of an experiment to test raster scanning with rotating unbalanced-mass devices on gimbaled payloads

An experiment designed to test the feasibility of using rotating unbalanced-mass (RUM) devices for line and raster scanning gimbaled payloads, while expending very little power is described. The experiment is configured for ground-based testing, but the scan concept is applicable to ground-based, balloon-borne, and space-based payloads, as well as free-flying spacecraft. The servos used in scanning are defined; the electronic hardware is specified; and a computer simulation model of the system is described. Simulation results are presented that predict system performance and verify the servo designs

Contactless Deformation Monitoring of Bridges with Spatio-Temporal Resolution: Profile Scanning and Microwave Interferometry

Against the background of an aging infrastructure, the condition assessment process of existing bridges is becoming an ever more challenging task for structural engineers. Short-term measurements and structural monitoring are valuable tools that can lead to a more accurate assessment of the remaining service life of structures. In this context, contactless sensors have great potential, as a wide range of applications can already be covered with relatively little effort and without having to interrupt traffic. In particular, profile scanning and microwave interferometry, have become increasingly important in the research field of bridge measurement and monitoring in recent years. In contrast to other contactless displacement sensors, both technologies enable a spatially distributed detection of absolute structural displacements. In addition, their high sampling rate enables the detection of the dynamic structural behaviour. This paper analyses the two sensor types in detail and discusses their advantages and disadvantages for the deformation monitoring of bridges. It focuses on a conceptual comparison between the two technologies and then discusses the main challenges related to their application in real-world structures in operation, highlighting the respective limitations of both sensors. The findings are illustrated with measurement results at a railway bridge in operation

Design optimisation of air-fed full pressurised suits

This article is a post-print version of the published article which may be accessed at the link below.The JET machine and associated facilities require significant maintenance and enhancement installation activities in support of the experimental exploitation programme. A proportion of these activities are within radiological and respiratory hazardous environments. As such, breathing air-fed one-piece pressurised suits provide workers with protection from the inhalation of both airborne tritium and beryllium dust. The design of these suits has essentially developed empirically. There is a practical necessity to improve the design to optimise worker performance, protection and thermal comfort. This paper details the complexity of modeling the three-dimensional thermofluid domain between the inner surface of the suit and under garments that includes mass as well as heat transfer, suiting geometry, human metabolism and respiration and effects of limb movements. The methods used include computational fluid dynamics (CFD), theoretical adaptations of mixed-phase turbulent flow, profile scanning of a suit and actuating life size mannequin and data processing of the images and experimental validation trials. The achievements of the current programme and collaborations are presented in the paper and future endeavors are discussed.The author gratefully acknowledges the loan of the articulated mannequin from the Defence Science and Technology Laboratories. This work was funded jointly by EPSRC and by the European Communities under the contract of Association between EURATOM and UKAEA. The views and opinions expressed herein do not necessarily reflect those of the European Commission. This work was carried out within the framework of EFDA

A new low profile antenna with improved performance for satellite on-the-move communications

A novel design solution for a low-profile fullduplex Satellite-On-The-Move Communications hybrid scanned phased array antenna for low elevation angle coverage (down to 10°) is described. The antenna is operated at Ku-Band. The unique louvered array element geometry in combination with a spatial filter/ “ray bending” lens facilitates the shaping of the element pattern to increase gain at low elevation angles. Preliminary modelling results using simple ray-tracing and 3D E simulation indicate that the desired low angle coverage can be achieved

Installation for SEE observation in the presence of magnetic field

The installation provides direct measurements of secondary emission yield and secondary electron velocity/energy distribution in the presence of magnetic field. The measurement system is designed to be installed into superconducting solenoid with maximum field of 10T. At present time the installation under commissioning at room temperature. The structure and performance capabilities of the setup are described, first experimental results are presented.Comment: 5 pages, contribution to the Joint INFN-CERN-EuCARD-AccNet Workshop on Electron-Cloud Effects: ECLOUD'12; 5-9 Jun 2012, La Biodola, Isola d'Elba, Ital

Phospho.ELM:a database of experimentally verified phosphorylation sites in eukaryotic proteins

BACKGROUND: Post-translational phosphorylation is one of the most common protein modifications. Phosphoserine, threonine and tyrosine residues play critical roles in the regulation of many cellular processes. The fast growing number of research reports on protein phosphorylation points to a general need for an accurate database dedicated to phosphorylation to provide easily retrievable information on phosphoproteins.DESCRIPTION: Phospho.ELM http://phospho.elm.eu.org is a new resource containing experimentally verified phosphorylation sites manually curated from the literature and is developed as part of the ELM (Eukaryotic Linear Motif) resource. Phospho.ELM constitutes the largest searchable collection of phosphorylation sites available to the research community. The Phospho.ELM entries store information about substrate proteins with the exact positions of residues known to be phosphorylated by cellular kinases. Additional annotation includes literature references, subcellular compartment, tissue distribution, and information about the signaling pathways involved as well as links to the molecular interaction database MINT. Phospho.ELM version 2.0 contains 1703 phosphorylation site instances for 556 phosphorylated proteins.CONCLUSION: Phospho.ELM will be a valuable tool both for molecular biologists working on protein phosphorylation sites and for bioinformaticians developing computational predictions on the specificity of phosphorylation reactions.</p