Facilities for the Energy Frontier of Nuclear Physics

The Relativistic Heavy Ion Collider at BNL has been exploring the energy frontier of nuclear physics since 2001. Its performance, flexibility and continued innovative upgrading can sustain its physics output for years to come. Now, the Large Hadron Collider at CERN is about to extend the frontier energy of laboratory nuclear collisions by more than an order of magnitude. In the coming years, its physics reach will evolve towards still higher energy, luminosity and varying collision species, within performance bounds set by accelerator technology and by nuclear physics itself. Complementary high-energy facilities will include fixed-target collisions at the CERN SPS, the FAIR complex at GSI and possible electron-ion colliders based on CEBAF at JLAB, RHIC at BNL or the LHC at CERN.Comment: Invited talk at the International Nuclear Physics Conference, Vancouver, Canada, 4-9 July 2010, to be published in Journal of Physics: Conference Series. http://inpc2010.triumf.ca

First observations of beam losses due to bound-free pair production in a heavy-ion collider

We report the first observations of beam losses due to bound-free pair production at the interaction point of a heavy-ion collider. This process is expected to be a major luminosity limit for the Large Hadron Collider (LHC) when it operates with 208Pb82+ ions because the localized energy deposition by the lost ions may quench superconducting magnet coils. Measurements were performed at the Relativistic Heavy Ion Collider (RHIC) during operation with 100 GeV/nucleon 63Cu29+ ions. At RHIC, the rate, energy and magnetic field are low enough so that magnet quenching is not an issue. The hadronic showers produced when the single-electron ions struck the RHIC beampipe were observed using an array of photodiodes. The measurement confirms the order of magnitude of the theoretical cross section previously calculated by others.Comment: 4 pages, 5 figures. Added journal ref. Corrected typos. Fixed fig 1. Minor improvements to fig. 1,3,4. Rephrased a small number of sentences (p1,3,4). Added numerical values of the aperture and the displacement for Au (p 2). Changed reference 5, added name in acknowledgments (p 4

Beam losses from ultra-peripheral nuclear collisions between Pb ions in the Large Hadron Collider and their alleviation

Electromagnetic interactions between colliding heavy ions at the Large Hadron Collider (LHC) at CERN will give rise to localized beam losses that may quench superconducting magnets, apart from contributing significantly to the luminosity decay. To quantify their impact on the operation of the collider, we have used a three-step simulation approach, which consists of optical tracking, a Monte-Carlo shower simulation and a thermal network model of the heat flow inside a magnet. We present simulation results for the case of Pb ion operation in the LHC, with focus on the ALICE interaction region, and show that the expected heat load during nominal Pb operation is 40% above the quench level. This limits the maximum achievable luminosity. Furthermore, we discuss methods of monitoring the losses and possible ways to alleviate their effect.Comment: 17 pages, 20 figure

Initial evidence for the criterion-related and structural validity of the long versions of the direct and meta-perspectives of the Coach-Athlete Relationship Questionnaire

This is the author's accepted manuscript. The final published article is available from the link below. Copyright @ 2010 Taylor & Francis.The aim of the present study was to develop and initially validate a longer version of the direct (Jowett & Ntoumanis, 2004) and meta-perspectives (Jowett, 2009a, 2009b) of the Coach-Athlete Relationship Questionnaire (CART-Q). In Study 1, instruments (e.g. questionnaires, scales, and inventories) that have been used to assess relationship quality in the broader psychological literature were examined and items potentially relevant to the coach-athlete relationship were identified. The content validity of the identified items was then assessed using expert panels. A final questionnaire was subsequently prepared and administered to 693 participants (310 coaches and 383 athletes). Confirmatory factor analysis was employed to assess the multidimensional nature of the questionnaire based on the 3Cs (i.e. closeness, commitment, and complementarity) model of the coach-athlete relationship. The findings indicated that the direct and meta-perspective items of the long versions of the CART-Q approached an adequate data fit. Moreover, evidence for the internal consistency and criterion validity of the new instruments was also obtained. In Study 2, the newly developed measure was administered to an independent sample of 251 individuals (145 athletes and 106 coaches). Further statistical support was gained for the factorial validity and reliability of the longer version of the CART-Q

Priorities and Preconditions for Successful Investment in Smallholder Agriculture in Sub-Saharan Africa

In the past couple of years, there has been resurgence in interest in smallholder agriculture as a potential driver for growth and poverty reduction in Sub-Saharan Africa. However, there remains considerable skepticism as to whether public investment in smallholder agriculture will lead to the desired growth and poverty reduction, given a general pessimism about "absorptive capacity" for (public) investment in Africa, the perception of failure of past agricultural investment and the observation that current conditions are unconducive to agricultural growth in Africa. This paper combines experiences of two UK-based NGOs dedicated to promoting smallholder agriculture and strengthening rural livelihoods in Africa with insights from academic literature on African agriculture and rural markets to set out an agenda for investment in smallholder agriculture in Africa. It identifies priorities for public investment, but also key issues related to "absorptive capacity" that need to be addressed if such investment is to succeed in generating agricultural growth and poverty reduction. Particular emphasis is placed on: a) investment in human and organisational capacity of smallholder farmers; b) investment in coordinated service provision to equip producers to respond to evolving market opportunities; c) the process of developing and implementing credible agricultural development strategies at both national and local level, and; d) reform of Ministries of Agriculture to support this process.International Development,

Attachment Styles Within the Coach-Athlete Dyad: Preliminary Investigation and Assessment Development

The present preliminary study aimed to develop and examine the psychometric properties of a new sport-specific self-report instrument designed to assess athletes’ and coaches’ attachment styles. The development and initial validation comprised three main phases. In Phase 1, a pool of items was generated based on pre-existing self-report attachment instruments, modified to reflect a coach and an athlete’s style of attachment. In Phase 2, the content validity of the items was assessed by a panel of experts. A final scale was developed and administered to 405 coaches and 298 athletes (N = 703 participants). In Phase 3, confirmatory factor analysis of the obtained data was conducted to determine the final items of the Coach-Athlete Attachment Scale (CAAS). Confirmatory factor analysis revealed acceptable goodness of fit indexes for a 3-first order factor model as well as a 2-first order factor model for both the athlete and the coach data, respectively. A secure attachment style positively predicted relationship satisfaction, while an insecure attachment style was a negative predictor of relationship satisfaction. The CAAS revealed initial psychometric properties of content, factorial, and predictive validity, as well as reliability

MAD Version 9

The program MAD is widely used for accelerator design and beam dynamics studies. For many years, its input language has been the nearest thing to a world-wide standard for describing accelerator structures. The new Version 9 is a complete rewrite using a systematic object-oriented methodology based on the CLASSIC classes [2] for accelerator physics. It provides many improvements over the previous MAD Version 8. These include: (i) support for multiple beam-lines simultaneously, facilitating, for example, matching constraints that couple the two rings of a two-ring collider, (ii) much improved Lie-algebraic map calculations, (iii) a uniform method and format for exchanging many kinds of structured data with other programs, (iv) an improved and more consistent input language. In addition, we report on a parallel 3D Poisson field solver for space charge calculations in high intensity particle beams. Applied to the PSI injector cyclotron, this shows the general nature of MAD Version 9 as a state-of- the-art problem-solving environment. We describe the current status of the program and how to get it, outline future plans and illustrate some of the new features

A new spatially and temporally variable sigma parameter in degree-day melt modelling of the Greenland Ice Sheet 1870–2013

The degree-day based method of calculating ice-/snow-melt across the Greenland Ice Sheet (GrIS) commonly includes the temperature parameter sigma (σ) accounting for temperature variability on short (sub-monthly down to hourly) timescales, in order to capture melt in months where the mean temperature is below 0 °C. Sigma is typically assumed to be constant in space and time, with values ranging from ~ 2.5 to 5.5 °C. It is unclear in many cases how these values were derived and little sensitivity analysis or validation has been conducted. Here we determine spatially and temporally varying monthly values of σ for the unique, extended 1870–2013 timescale based on downscaled, corrected European Centre for Medium-Range Weather Forecasts (ECMWF) Interim (ERA-I) and Twentieth Century Reanalysis (20CR) meteorological reanalysis 2 m air temperatures on a 5 km × 5 km polar stereographic grid for the GrIS. The resulting monthly σ values reveal a distinct seasonal cycle. The mean summer σ value for the study period is ~ 3.2 °C, around 1 °C lower than the value of 4.2 °C commonly used in the literature. Sigma values for individual summers range from 1.7 to 5.9 °C. Since the summer months dominate the melt calculation, use of the new variable σ parameter would lead to a smaller melt area and a more positive surface mass balance for the GrIS. Validation of our new variable σ dataset shows good agreement with standard deviations calculated from automatic weather station observations across the ice sheet. Trend analysis shows large areas of the ice sheet exhibit statistically significant increasing temperature variability from 1870–2013 in all seasons, with notable exceptions around Summit in spring, and Summit and South Dome in winter. More recently, since 1990, σ has been decreasing, significantly so in the north-west during July. These interannual σ trends reflect climate change and variability processes operating across the ice sheet, several mechanisms of which are briefly discussed

Physics Opportunities with the FCC-hh Injectors

In this chapter we explore a few examples of physics opportunities using the existing chain of accelerators at CERN, including potential upgrades. In this context the LHC ring is also considered as a part of the injector system. The objective is to find examples that constitute sensitive probes of New Physics that ideally cannot be done elsewhere or can be done significantly better at theCERN accelerator complex. Some of these physics opportunities may require a more flexible injector complex with additional functionality than that just needed to inject protons into the FCC-hh at the right energy, intensity and bunch structure. Therefore it is timely to discuss these options concurrently with the conceptual design of the FCC-hh injector system.Comment: 13 pages, chapter 5 in Physics at the FCC-hh, a 100 TeV pp collide