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| MOPLT096 | Machine Induced Background in the High Luminosity Experimental Insertion of the LHC Project | background, hadron, insertion, simulation | 755 | ||
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The methodical approach, developed for the solution of the radiation problems in the LHC project, is used for the estimation of the machine induced background in the high luminosity experimental insertion IR1. The results of the cascade simulations are presented for the cases of the proton losses in the cold and warm parts of the collider. The formation of the machine induced background in the interaction region is discussed.
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| MOPLT105 | Implementation of MICE at RAL | vacuum, emittance, synchrotron, target | 779 | ||
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The Muon Ionisation Cooling Experiment (MICE) is motivated by the vision of the neutrino factory (NF). The cost and practicality of the NF depends on an early control of the emittance of the muon beam that will be accelerated and stored to produce the neutrino beams. A number of possibilities for transverse cooling of the emittance have been proposed including ionisation cooling. In such a concept, the muon beam is alternatively slowed down in cryogenic absorbers (energy loss by ionisation) and then re-accelerated in RF cavities to replace the lost energy. This process reduces the transverse momentum of the beam while maintaining the average momentum in the z-direction. The energy absorbing material should be characterised by a high stopping power and low multiple scattering: The material of choice is liquid hydrogen. MICE will replicate a piece of the NF cooling channel. The engineering of a safe system with thin windows for the containment of the liquid hydrogen and other features needed to safely operate will test the practical application of the cooling scheme and its performance. MICE is proof of principle for this untried technology. The paper reviews progress in MICE and the plans for its implementation at RAL.
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The MICE Collaboration |
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| MOPLT114 | Modeling of Beam Loss in Tevatron and Backgrounds in the BTeV Detector | beam-losses, hadron, collimation, background | 803 | ||
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Detailed STRUCT simulations are performed of beam loss rates in the vicinity of the BTeV detector in the Tevatron C0 interaction region due to beam-gas nuclear elastic interactions, outscattering from the collimator jaws and an accidental abort kicker prefire. Corresponding showers induced in the machine components and background rates on the BTeV Detector are modeled with the MARS14 code. It is shown that a steel mask located in front of the last four dipoles upstream the C0 can reduce the accelerator-related background rates in the detector by an order of magnitude.
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| WEPLT002 | Shielding Design Study for CANDLE Facility | beam-losses, radiation, electron, storage-ring | 1816 | ||
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The radiation shielding design study for the third generation synchrotron light source CANDLE is carried out. The electron beam loss estimates have done for all the stages from linac to storage ring. A well-known macroscopic model describing the dose rate for point losses has been used to calculate the shielding design requirements of the facility.
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| WEPLT007 | Installation of the LHC Experimental Insertions | quadrupole, insertion, luminosity, interaction-region | 1828 | ||
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The installation of the LHC experimental insertions, and particularly the installation of the low-beta quadrupoles, raises many technical challenges due to the stringent alignment specifications and to the difficulty of access in very confined areas. The compact layout with many lattice elements, vacuum components, beam control instrumentations and the presence of shielding does not allow for any improvisation in the installation procedure. This paper reviews all the constraints that need to be taken into account when installing the experimental insertions. It describes the chronological sequence of installation and discusses the technical solutions that have been retained.
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| WEPLT011 | Transport and Handling of LHC Components: a Permanent Challenge | site, simulation, collider, cryogenics | 1840 | ||
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The LHC project, collider and experiments, is an assembly of thousands of elements, large or small, heavy or light, fragile. Every one of those has own transport requirements that constituting for us a real challenge to handle. The manoeuvres could be simple, but the complex environment and narrow underground spaces may lead to difficulties in integration, routing and execution. Examples of transport and handling of typical LHC elements will be detailed: the 17m long, 35t heavy but fragile cryomagnets from the surface to the final destination in the tunnel, the delicate cryogenic cold-boxes down to pits and detector components. This challenge did not only require a lot of imagination but also the close cooperation between all involved parties, in particular with colleagues from safety, cryogenics, civil engineering, integration and logistics.
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| WEPLT027 | Connection Cryostats for LHC Dispersion Suppressors | alignment, dipole, vacuum, radiation | 1888 | ||
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The lattice of the Large Hadron Collider (LHC) being built at CERN is based on 8 standard arcs of 2.8 km length. Each arc is bounded on either side by Dispersion Suppressors connected to the arc by connection cryostats providing 15m long drift spaces. As for a dipole magnet, the connection cryostat provides a continuity of beam and insulation vacuum, electrical powering, cryogenic circuits, thermal and radiation shielding. In total 16 modules will be constructed. The stringent functional specification has led to various analyses. Among them, a light mechanical structure has been developed to obtain a stiffness comparable to a dipole magnet, for alignment purpose. Thermal studies, included λ front propagation, have been performed to ensure a cooling time down to 1.9K within the time budget. A special cooling scheme around the beam tubes has been chosen to cope with heat loads produced during operation. We will report on the general design of the module and on the manufacturing process adopted to guarantee the tight alignment of the beam tubes once the module installed in the machine. Special emphasis will be given on thermo-mechanical analysis, λ front propagation and on beam-tubes cooling scheme.
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| WEPLT095 | Modified Polarizabilities and Wall Impedance for Shielded Perforated Beam Pipes with General Shape | impedance, coupling, vacuum, dipole | 2074 | ||
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We extend previous results [*] concerning the modified polarizability of (electrically small) holes/slots in the wall of a circular beam liner surrounded by a coaxial circular tube to the most general liner and cold bore geometries. We obtain an equivalent wall impedance to describe the electromagnetic boundary conditions at perforated walls for this most general case, and use a general perturbational approach [**] for computing the pertinent longitudinal and transverse coupling impedances.
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* R.L. Gluckstern, CERN SL 92-06 (AP), 1992, CERN SL 92-31 (AP), 1992; R.L. Gluckstern, B. Zotter, CERN SL 96-56 (AP), 1996.** S. Petracca, Part. Acc., {\bf 50}, 211, 1995; id., Phys. Rev. E, 60 (3),1999. |
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| WEPLT172 | Design & Handling of High Activity Collimators &Ring Components on the SNS | vacuum, target, linac, extraction | 2233 | ||
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Design & Handling of High Activity Collimators on the SNS*G Murdoch,S Henderson, K Potter,T Roseberry,Oak Ridge National Laboratory, USA,H Ludewig, N Simos, Brookhaven National Laboratory, USAJ Hirst, Rutherford Appleton Laboratory,UK, The Spallation Neutron Source accelerator systems will provide a 1GeV, 1.44MW proton beam to a liquid mercury target for neutron production. The expected highest doses to components are in the collimator regions. This paper presents the mechanical engineering design of a typical collimator highlighting the design features incorporated to assist with removal once it is activated. These features include shielding and lifting fixtures but more importantly a double contained flexible water system incorporating remote water couplings.Also presented is a mechanism that allows axial removal of vacuum bellows and its associated vacuum clamps.*SNS is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. Department of Energy. SNS is a partnership of six national laboratories: Argonne, Brookhaven, Jefferson, Lawrence Berkeley, Los Alamos and Oak Ridge.
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| THPKF061 | RT-office for Electron Beam, X-ray, and Gamma-ray Dosimetry | target, simulation, electron, radiation | 2403 | ||
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An absorbed dose of electron beam (EB),X-ray (bremsstrahlung), and gamma-ray within the irradiated product is one of the most important characteristic for all industrial radiation-technological processes. The conception for design of the Radiation-Technological Office (RT-Office) - software tools for EB, X-ray, and gamma-ray dosimetry for industrial radiation technologies was developed by authors. RT-Office realize computer technologies at all basic stages of works execution on the RTL using irradiators of EB, X-ray, and gamma-ray in the energy range from 0.1 to 25 MeV. The specialized programs for simulation of EB, X-ray, and gamma-ray processing and for decision of special tasks in dosimetry of various radiation technologies were designed on basis of the RT-Office modules. The use of the developed programs as predictive tools for EB,X-ray, and gamma-ray dose mapping, for optimization of regimes irradiation to receive minimum for dose uniformity ratio, for reducing the volume of routine dosimetry measurements of an absorbed dose within materials at realization of the radiation-technological processes are discussed in the paper.
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| THPKF082 | The Completion of SPEAR 3 | vacuum, power-supply, injection, radiation | 2451 | ||
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On December 15, 2003, 8 1/2 months after the last electrons circulated in the old SPEAR2 storage ring and 5 days after the beginning of commissioning, the first electrons were accumulated in the completely new SPEAR3 ring. The rapid installation and commissioning is a testimony to the SPEAR3 project staff and collaborators who have built an excellent machine and equipped it with powerful and accessible machine modeling and control programs. The final year of component fabrication, system implementation and testing, the 7-month installation period leading up to the beginning of commissioning, and lessons learned are described.
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| THPLT145 | Automated High-power Conditioning of Medical Accelerators | radiation, medical-accelerators, vacuum, ion | 2795 | ||
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Medical accelerators require arc-free operation. Due to high-field emission, arcing and outgasing can occur in high-power accelerators. Therefore, the accelerator?s inner surfaces have to be conditioned before its use at high gradient levels in Radiation Therapy machine. At Siemens, we have developed a techniqu·101 to automatically condition an accelerator waveguide structure by continually inspecting the accelerator running conditions (arcing and vacuum) and stepping up the pulse repetition frequency (PRF) and RF power until reaching maximum power rating. The program implemented also reads, displays, and archives the data it collects along the full process of conditioning.
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