Performance of LHC Main Dipoles for Beam Operation

At present about 90% of the main dipoles for the LHC have been manufactured and one of the three cold mass assemblers has already completed the production. 85% of the 1232 dipoles needed for the tunnel have been tested and accepted. In this paper we mainly deal with the performance results: the quench behaviour, the magnetic field quality, the electrical integrity quality and the geometry features will be summarized

Axis measurements, field quality and quench performance of the first LHC short straight sections

The series testing at 1.9 K of the 360 Short Straight Sections (SSS) for the Large Hadron Collider have started at CERN in September 2003. The SSS contain the lattice quadrupoles and correction magnets in a common cryostat. The lattice quadrupoles feature two collared coils with 56 mm bore assembled in a common yoke. The coils are wound in two-layers from 15.1 mm wide NbTi cable, insulated with polyimide tape. The paper reviews the main test results performed in superfluid helium. The magnetic field and magnetic center position of the quadrupoles and associated correctors were measured with two independent systems, namely an automated scanner and a single stretched wire technique. The quench training, the field quality and the magnetic alignment measurements are presented and discussed in terms of the specifications and expected performances of these magnets in the LHC. We discuss in detail the field quality in terms of multipole errors measured at injection and nominal field and decomposed into geometric and persistent current magnetization errors. Warm/cold correlation for the geometric multipoles and the magnetic axis is also presented.peer-reviewe

Testing of the LHC Magnets in Cryogenic Conditions: Operation Challenges, Status and Outlook

For the Large Hadron Collider under construction at CERN and the testing of its 1706 Cryo-magnets in cryogenic conditions, considerable challenges had to be overcome since 2002 to arrive at the situation of today, with semi-routine operation of the purpose built tests facility. With the setting up of an Operation Team comprising of few non-expert CERN Accelerator operation staff, and a large external collaboration, it was essential to develop the methodology of working in light of external collaboration limits and base it on CERN-known techniques and experience in accelerator running-in, commissioning and routine operation. A flavour of the operation tools that were necessary or developed will be given, i.e., web-based tests follow-up management & information systems, development of precisely defined 'to do list' of tests sequences, associated methods, procedures and strict check-lists, electronic logbooks and so forth. The presentation will briefly outline the tests operation programme and its context & constraints, give a summary of the accomplishments so far, together with the outlook for the successful completion of the whole programme within the project goals

Simon van der Meer and his legacy to CERN and particle accelerators

Simon van der Meer was a brilliant scientist and a true giant in the field of accelerators. His seminal contributions to accelerator science are essential to this day in our quest to satisfy the demands of modern particle physics. Whether we are talking of long-baseline neutrino physics or antiproton-proton physics at CERN and Fermilab, or proton-proton physics at the LHC, his techniques and inventions have been a vital and necessary part of modern-day successes. Simon van der Meer and Carlo Rubbia were the first CERN scientists to become Nobel laureates in Physics in 1984. His less well-known contributions spanned a whole range of subjects in accelerator science from magnet design to power supply design, beam measurements, slow beam extraction, sophisticated programs, and controls.Simon van der Meer was a brilliant scientist and a true giant in the field of accelerators. His seminal contributions to accelerator science are essential to this day in our quest to satisfy the demands of modern particle physics. Whether we are talking of long-baseline neutrino physics or antiproton-proton physics at CERN and Fermilab, or proton-proton physics at the LHC, his techniques and inventions have been a vital and necessary part of modern-day successes. Simon van der Meer and Carlo Rubbia were the first CERN scientists to become Nobel laureates in Physics in 1984. His less well-known contributions spanned a whole range of subjects in accelerator science from magnet design to power supply design, beam measurements, slow beam extraction, sophisticated programs, and controls

Simon van der Meer (1925-2011): A modest genius of accelerator science

Simon van der Meer was a brilliant scientist and a true giant of accelerator science. His seminal contributions to accelerator science have been essential to this day in our quest for satisfying the demands of modern particle physics. Whether we talk of long base-line neutrino physics or antiproton-proton physics at Fermilab or proton-proton physics at LHC, his techniques and inventions have been a vital part of the modern day successes. Simon van der Meer and Carlo Rubbia were the first CERN scientists to become Nobel laureates in Physics, in 1984. Van der Meer's lesser-known contributions spanned a whole range of subjects in accelerator science, from magnet design to power supply design, beam measurements, slow beam extraction, sophisticated programs and controls

Organizational decision making and participation in an interorganizational service network

This study attempts to identify the variables associated with an organization\u27s decision to participate in an interorganizational service network. The survev of literature on the subject supported the hypothesis that structural variables of complexity, formalization, and centralization and a psychological variable, the awareness of organizational interdependency, are associated with the decision to participate. Interorganizational participation was operationally defined in terms of various behavioral components: an organization\u27s involvement with the coordinating agency, client referrals to and from other organizations and to and from the coordinating agency, and information exchanged with other organizations and with the coordinating agency. Using this framework, testable hypotheses were formulated regarding the relationship between the selected measures of the independent variables of complexity, formalization, centralization, and awareness of interdependency and the dependent variable of interorganizational participation. Human service agencies which provide services to the elderly in the State of Oregon were surveyed in this study. These agencies, together with the Area Agency on Aging, a coordinating agency established under the Older Americans Act, constituted the interorganizational service network. A main concern of that type of coordinating agency is to facilitate effective working relationships between the organizations in such service networks. This study was designed to explore the factors associated with that process. Findings and Conclusions: The evidence presented suggests that the psychological variable of awareness of interdependency is significantly related to the decision to participate. This finding was generally supported by qualitative data gathered from six organizations examined under the case study method. For the structural variable it was found that: a) complexity was not significantly related to the decision to participate; b) centralization had a significant relationship with only some components of the measures of participation; c) there was some association between formalization and the participation processes. In general, it appears that a key step to building effective networks of service organizations is to increase awareness of interdependency among organizational members