CERN Accelerating science

This website is no longer maintained. Its content may be obsolete. Please visit http://home.cern for current CERN information.

LHC Project Seminars (3)


Transparencies presented at LHC Project Seminars (2004-2006) are made available on this page.
Access previous seminar transparencies: 2000-2002 2003

Thursday 2 February 2006 - Possible SPS experiments to test crystal collimation for the LHC

by Walter Scandale, CERN. We recently suggested using short bent crystals as primary collimators in a two stage cleaning system for hadron colliders, with the aim of providing larger impact parameters in the secondary bulk absorber through coherent beam-halo deflection. Tests with crystals a few mm long, performed with 70 GeV proton beams at IEHP in Protvino, showed a channeling efficiency exceeding 85 %. We also observed disturbing phenomena such as dechanneling at large impact angles, insufficient bending induced by volume capture inside the crystal, multiple scattering of non-channeled protons and, for the first time, a proton flux reflected by the crystalline planes. The proposed experiments in the SPS should contribute to consolidating our knowledge of channeling and dechanneling phenomena and will provide a test bed for crystals to be eventually used in the LHC collimation system.

Wednesday 18 January 2006 - International Linear Collider R&D at Fermilab

by Shekhar Mishra, Fermilab.. The International Linear Collider (ILC) is a proposed future international particle accelerator. It would create high-energy particle collisions between electrons and positrons. Fermilab is working in several Accelerator R&D topics for the ILC with a lead role in the Main Linac design in USA, specially the Superconducting RF. Fermilab is a proposed site of the ILC in U.S.A. The ILC R&D at Fermilab in context with the International R&D will be presented.

Thursday 17 November 2005 - EDMS Support over the LHC project lifecycle

by Elena Manola-Poggioli (TS-CSE, for the EDMS Team), CERN .. The CERN Engineering Data Management Service (EDMS) project was launched in June 1997, with the objective to provide engineering and equipment data management services for the LHC project over its entire life-cycle. Offering the required tools for document and drawing management for the specification phase, the EDMS service timely provided equipment data management when the manufacturing phase started. This seminar describes the continued evolution of the service throughout the different phases of the LHC project: design, manufacturing, installation and hardware commissioning, the present status as well as the future perspectives of operation and maintenance.

Thursday 10 November 2005 - Scenarios for the luminosity upgrade in the LHC

by Francesco Ruggiero (AB/ABP) and Walter Scandale (AT/MAS), CERN. In a few years, the LHC luminosity will reach the nominal value of 1034 cm-2 s-1. . To go beyond, one can only think of increasing the circulating beam current to the ultimate intensity at the edge of the beam-beam interaction limit. In a recent workshop sponsored by the CARE-HHH network, we investigated possible ways to increase the luminosity performance by an order of magnitude by improving the insertion layout and the injector complex. This would require a vigorous R&D programme, addressing high-field magnets, fast pulsed magnets, radiofrequency sources and cavities, beam dynamics scenarios, accelerator protection and cleaning systems. In this seminar the highlights of the workshop will be presented and critically discussed.

Thursday 13 October 2005 - A Monte Carlo Model of Tevatron Operations

by Elliott McCrory, Fermilab.. A Monte Carlo model of Tevatron operations has been constructed to help us determine the optimal manner to run the Complex. This model includes randomizations on essentially all processes, including transmission efficiencies, emittances, beam intensities, luminosities, injector performance, antiproton collection issues and downtime. Analytical formulations are used, but phenomenological considerations are paramount. Shot Data Acquisition (SDA) provides data that connects the model to reality. Present performance is presented and future performance is predicted, along with many interesting things we have learned along the way.

Monday 26 September 2005 - The Superconducting QUantum Interference Device: Principles and Applications

by John Clarke (University of California, Berkeley, and Lawrence Berkeley National Laboratory). .. The SQUID (Superconducting QUantum Interference Device) - a superconducting loop containing two Josephson junctions - is an ultrasensitive detector of magnetic flux. The principles, fabrication, and operation of the SQUID are outlined. With the aid of a superconducting flux transformer, the SQUID achieves a magnetic field noise of 10-15 T Hz-1/2; it can also be configured as a voltmeter with a noise of 10-15 V Hz-1/2. Applications of SQUIDs - ranging from geophysics to medicine and from nondestructive evaluation to quantum computing - are briefly reviewed. Two other applications are discussed in more detail. The first is a SQUID as a near-quantum-limited amplifier in the 1-GHz frequency range. This device is to be installed in the axion detector at Lawrence Livermore National Laboratory in 2006, and is expected to increase the frequency scan rate by three orders of magnitude. In the second example, a SQUID is used to acquire magnetic resonance images at 5.6 kHz, four orders of magnitude lower than in conventional MRI systems. Images of phantoms and of the human forearm are presented, enhanced contrast due to weighting by the longitudinal relaxation time is illustrated, and the ability to obtain undistorted images in the presence of metals is demonstrated. Potential clinical applications are discussed.

Thursday 28 July 2005 - Computational Fluid Dynamics at CERN

by Michele Battistin, CFD team (TS-CV). . Computational Fluid Dynamics (CFD) allows us to develop 3D models and find numerical solutions of thermal and fluid flow problems in confined spaces. Since 1993, CFD has been used at CERN, in particular in the TS-CV group, to solve several problems on thermo-fluid dynamics, especially related to LHC experiments during their development, design and construction phases. 3D models can be analysed numerically reducing the effort required for prototype testing, thus saving time, money and allowing for additional investigation and design optimisation. Increases in computer power and the next generation of Grid computational systems are giving and will give greater opportunities to continue developing this science/technique. The CFD team already supports many CERN design and construction units in the development of engineering solutions, especially for the LHC experiments and CNGS project. A number of different cases will be presented and discussed to illustrate the potential applications for the AT Department.

Friday 10 June 2005 - RHIC Commissioning

by Mike Harrison (BNL).. There has only been three large super-conducting accelerators built to date, the most recent, the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory. I will review the early commissioning of the machine covering the final stages of hardware installation and the initial beam operation. Covering topics such as tunnel installation, vacuum, cryogenics and power converters I will look at items that caused problems and answer the time honoured conundrum of 'how many engineering does it take commission a power converter ?'

Thursday 14 April 2005 - 25 Tesla Hybrid Dipoles for an LHC Energy Tripler (and other system requirements)

by Peter McIntyre (Texas A&M University).. The LHC Tripler is a conceptual design for a 20 TeV/beam hadron collider that could be installed above the LHC to triple the collision energy and double the mass reach for new gauge fields. It employs hybrid dipoles, containing windings of both Bi-2212 and Nb3Sn to reach 25 Tesla field strength. These dipoles employ technical innovations that have come from the development of the current state of the art in Nb3Sn dipoles: block-coil geometry, stress management, bladder preload, and flux plate suppression of persistent current multipoles. Recent progress in evaluating some of the many system requirements for this upgrade will be reported: absorption of synchrotron light on 160 K photon stops, injection from a 1 TeV rapid-cycling super-SPS, low-beta squeeze and impact on existing detectors, suppression of electron cloud effect, and abort requirements. A proposal to begin an R&D collaboration to develop the required dipole technology will be presented.

Thursday 3 February 2005 - Prospects for High Field Nb3Sn Dipoles

by Shlomo Caspi (LBL).. The talk will focus on Nb3Sn superconducting accelerator magnets and address technical issues on three different subjects: 1) A short summary of the US LARP quadrupole magnet program and the status of the first model magnets. 2) R&D on high field magnets - the base program at Lawrence Berkeley National Laboratory. 3) Scaling and limits of Nb3Sn dipoles - how do we approach this challenge.

Thursday 30 September 2004 - Thermohydraulic of He II flows: the cooling of LHC magnet cells as a practical example

by Bernard Rousset (CEA-Grenoble), Pierre Thibault (CNRS-Grenoble).. In the framework of the R&D for the LHC cooling scheme (i.e. heat exchanger pipe), Superfluid helium (He II) flows were studied at Grenoble. Initially convection of pure liquid and later counter and co-current two-phase flow were investigated. In this talk, we will mainly focus on co-current HeII two-phase flow, as it is the solution adopted for the LHC. Original sensors such as capacitive probes or thermal "flag" will be presented. Video sequences of He II two-phase flow will also be shown.

Thursday 19 February 2004 - Web-based tools for LHC cryodipoles field quality follow-up

by L. Deniau, AT Department. This seminar will present the web-based tools provided by AT-MTM to make easier the follow-up of the LHC main dipoles field quality at the different stages of production (collared-coils, cold-masses and cryo-assembly). The presentation will start by a short introduction to the software to make the user familiar with the web interfaces. It will next focus on the available standard analysis like magnet cards, magnet properties, production sequences, warm-cold correlations and warm-cold distributions. Some examples will be given to help in the interpretation of the results. The presentation will conclude by showing how to retrieve the analyzed data and plans for further studies or publications.