Effect of pulsed hollow electron-lens operation on the proton beam core in LHC

Collimation with hollow electron beams is currently one of the most promising concepts for active halo control in the HL-LHC. In order to further increase the diffusion rates for a fast halo removal as e.g. desired before the squeeze, the electron lens (e-lens) can be operated in pulsed mode. In case of profile imperfections in the electron beam the pulsing of the e-lens induces noise on the proton beam which can, depending on the frequency content and strength, lead to emittance growth. In order to study the sensitivity to the pulsing pattern and the amplitude, a beam study (machine development MD) at the LHC has been proposed for August 2016 and we present in this note the preparatory simulations and estimates

Resonant and random excitations on the proton beam in the Large Hadron Collider for active halo control with pulsed hollow electron lenses

We present the results of numerical simulations and experimental studies about the effects of resonant and random excitations on proton losses, emittances, and beam distributions in the Large Hadron Collider (LHC). In addition to shedding light on complex nonlinear effects, these studies are applied to the design of hollow electron lenses (HEL) for active beam halo control. In the High-Luminosity Large Hadron Collider (HL-LHC), a considerable amount of energy will be stored in the beam tails. To control and clean the beam halo, the installation of two hollow electron lenses, one per beam, is being considered. In standard electron-lens operation, a proton bunch sees the same electron current at every revolution. Pulsed electron beam operation (i.e., different currents for different turns) is also considered, because it can widen the range of achievable halo removal rates. For an axially symmetric electron beam, only protons in the halo are excited. If a residual field is present at the location of the beam core, these particles are exposed to time-dependent transverse kicks and to noise. We discuss the numerical simulations and the experiments conducted in 2016 and 2017 at injection energy in the LHC. The excitation patterns were generated by the transverse feedback and damping system, which acted as a flexible source of dipole kicks. Proton beam losses, emittances, and transverse distributions were recorded as a function of excitation patterns and strengths. The resonant excitations induced rich dynamical effects and nontrivial changes of the beam distributions, which, to our knowledge, have not previously been observed and studied in this detail. We conclude with a discussion of the tolerable and achievable residual fields and proposals for further studies.Comment: 33 pages, 32 figures, 46 references. Revised manuscript submitted to Phys. Rev. Accel. Beam

Towards assessing the networkability of health care providers: a maturity model approach

This paper presents a networkability maturity model as an approach to assess a health care organisation's capacity with regards to being able to efficiently engage in business relationships. Continuously rising costs and increasingly restrained budgets for health care put pressure on the public health systems. A low division of labour and integration of processes along cross-organisational patient therapy provides large potential for improvements in efficiency and efficacy. It is the aim of the presented model to enable identification of potentials for improvements and respective measures to advance the ability to benefit from specialisation and collaboration along the value chain. The presented model is developed based on a classification of related state-of-the-art in maturity models to assess individual factors of networkability which are integrated to form an overall framework comprising six components and respective factors to be assessed. As networkability maturity addresses the interrelation of strategy, organisational design and information systems design, the paper adheres to requirements for effective design science research applied to the process of construction of a networkability maturity model applicable for health care providers. It therefore concludes with a case-based evaluation according to the design research literature and identification of further researc

Dynamic simulations in SixTrack

The DYNK module allows element settings in SixTrack to be changed on a turn-by-turn basis. This document contains a technical description of the DYNK module in SixTrack. It is mainly intended for a developer or advanced user who wants to modify the DYNK module, for example by adding more functions that can be used to calculate new element settings, or to add support for new elements that can be used with DYNK.Comment: Submission to CERN yellow report / conference proceeding, the 2015 collimation tracking code worksho

A Review of Existing Studies Reporting the Negative Effects of Alcohol Access and Positive Effects of Alcohol Control Policies on Interpersonal Violence

Alcohol consumption often leads to elevated rates of violence yet alcohol access policies continue to relax across the globe. Our review establishes the extent alcohol policy can moderate violent crime through alcohol availability restrictions. Results were informed from comprehensive selection of peer-reviewed journals from 1950 to October 2015. Our search identified 88 relevant studies on alcohol access and violence conducted across 12 countries. Seventeen studies included quasi-control design, and 23 conducted intervention analysis. Seventy-two (82%) reported a significant relationship between alcohol access and violent offences. Alcohol outlet studies reported the greatest percentage of significant results (93%), with trading hours (63%), and alcohol price following (58%). Results from baseline studies indicated the effectiveness of increasing the price of commonly consumed alcohol, restricting the hours of alcohol trading, and limiting the number of alcohol outlets per region to prevent violent offences. Unclear are the effects of tax reductions, restriction of on-premises re-entry, and different outlet types on violent crime. Further, the generalization of statistics over broad areas and the low number of control/intervention studies poses some concern for confounding or correlated effects on study results, and amount of information for local level prevention of interpersonal violence. Future studies should focus on gathering longitudinal data, validating models, limiting crime data to peak drinking days and times, and wherever possible collecting the joint distribution between violent crime, intoxication, and place. A greater up take of local level analysis will benefit studies comparing the influence of multiple alcohol establishment types by relating the location of a crime to establishment proximity. Despite, some uncertainties particular studies showed that even modest policy changes such as 1% increases in alcohol price, one hour changes to closing times, and limiting establishment densities to less than 25 outlets per postal code substantively reduce violent crime

90 m optics commissioning

http://accelconf.web.cern.ch/AccelConf/IPAC2011/papers/tupz001.pdfInternational audienceSpecial β∗ = 90 m optics have been developed for the two very high luminosity insertions of the LHC [1] [2], as a rst step to allow for very low angle precision measure- ments of the proton-proton collisions in the LHC. These optics were developed to be compatible with the stan- dard LHC injection and ramp optics. The target value of β∗ = 90 m is reached by an un-squeeze from the injection β∗ = 11 m. We report about the implementation of this op- tics and the rst experience gained in commissioning with beam during two machine studies

The Effectiveness of Student Led Conferencing in an Intermediate Setting

The studied focused on the communication between parents, teachers and students and the student self-reflection of strengths, weaknesses, and goals during Student Led Conferencing. Twenty-five students in a sixth grade classroom created student led conference portfolios and participated in fall and spring conferences with their teacher and parents. The specific parts of each of the pieces of the portfolio and conferences are examined. The results showed a highly effective rate in the desired areas

INTERCULTURAL COMMUNICATION & PROFESSIONAL ATHLETES: A QUALITATIVE ANALYSIS ON THE ACCULTURATION EXPERIENCE OF NORTH AMERICAN WOMEN COMPETING INTERNATIONALLY AT THE PROFESSIONAL INDOOR VOLLEYBALL LEVEL

M.A.M.A. Thesis. University of Hawaiʻi at Mānoa 201

Halo and tail simulations with applications to the CLIC drive beam

We report about generic halo and tail simulations and estimates. Previous studies weremainly focused on very high energies as relevant for the beam delivery systems of linear colliders. We have now studied, applied and extended these simulations to lower energies as relevant for the CLIC drive beam