| Paper | Title | Other Keywords | Page |
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| MOPPD061 | LHC@home: a Volunteer Computing System for Massive Numerical Simulations of Beam Dynamics and High Energy Physics Events | HOM, simulation, collider, controls | 505 |
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| Recently, the LHC@home system has been revived at CERN. It is a volunteer computing system based on BOINC which allows boosting the available CPU-power in institutional computer centers by the help of individuals that donate the CPU-time of their PCs. Currently two projects are hosted on the system, namely SixTrack and Test4Theory. The first is aimed at performing beam dynamics simulations, while the latter deals with the simulation of high-energy events. In this paper the details of the global system, as well a discussion of the capabilities of either project will be presented. Milestones of progress of the projects will also be discussed. | |||
| MOPPD079 | Preliminary Thermo-Mechanical Analysis of Angular Beam Impact on LHC Collimators | simulation, collimation, kicker, controls | 550 |
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Funding: This work is supported by EuCARD. The correct functioning of the LHC collimation system is crucial to attain the desired LHC luminosity performance. However, the requirements to handle high intensity beams can be demanding. In this respect, accident scenarios must be well studied in order to assess if the collimator design is robust against likely error scenarios. One of the catastrophic - though not very probable - accident scenarios identified is an asynchronous beam dump coupled with slight angular misalignment errors of the collimator jaw. Previous work presented a preliminary thermal evaluation of the extent of beam-induced damage for such scenarios, where it was shown that in some cases, a tilt of the jaw could actually serve to mitigate the effect of an asynchronous dump on the collimators. This paper will further analyze the response of tertiary collimators in presence of such angular jaw alignments, with the aim to identify optimal operational conditions. |
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| WEPPD029 | The Mechanical Design of a Collimator and Cryogenic Bypass for Installation in the Dispersion Suppressors of the LHC | cryogenics, vacuum, shielding, collimation | 2567 |
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| A project to install collimators in the dispersion suppressor regions of the LHC was launched early 2010, aiming to reduce the power deposition in superconducting magnets by a factor of 10. To be placed in the continuous arc cryostat, the design of such collimators had to comply with challenging integration, functional and time constraints. A pre-study for a cold collimator solution was launched in parallel with an alternative design consisting of a room temperature collimator and a cryogenic bypass. The second was eventually preferred, as it was based on proven LHC technologies for cryogenic, vacuum, electrical and collimator material solutions, despite the increased difficulty on the mechanical integration and assembly. This paper presents the mechanical design of a cryogenic bypass for the LHC continuous cryostat and respective collimator unit, both made to comply with the functionality of existing LHC systems. The approach taken to achieve a reliable design within schedule will be explained alongside the measures adopted to validate new solutions, in particular, when dealing with welding distortions, systems routing, thermal loads and precision mechanics. | |||
| THPPD023 | Solenoid Field Calculation of the SuperKEKB Interaction Region | solenoid, quadrupole, interaction-region, optics | 3548 |
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| The SuperKEKB is the electron-positron collider, and the target luminosity is 8×1035 cm-2s−1, which is 40 times larger than the attained luminosity of KEKB. The beam final focus system consists of many types of superconducting magnets as 8 quadrupoles, 40 correctors and 4 compensation solenoids. These focusing magnets and correctors are designed to be operated inside the particle detector, Belle, and under the solenoid field of 1.5 T. From the analysis of beam optics, the solenoid field profile has serious impact on the beam vertical emittance. We designs the solenoid field profile along the Belle axis in a 2-dimensional model as the first step, and now we developed this model to the 3-dimensional calculation in detail. The solenoid field profiles along the both beam lines are generated with the combine solenoid field by the Belle solenoid and the compensation solenoids, and the magnetic components of the magnets and the magnetic shields on the beam lines. The model is very complicate. From the calculation results, we will discuss the influence on the beam optics and the final focusing magnet system. | |||
| THPPD024 | Irradiation Effects in Superconducting Magnet Materials at Low Temperature | neutron, radiation, solenoid, target | 3551 |
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| Superconducting magnets for high intensity accelerators and particle sources are exposed to severe radiation from beam collisions and other beam losses. Neutron fluence on the superconducting magnets for the next generation projects of high energy particle physics, such as LHC upgrades and the COMET experiment at J-PARC, is expected to exceed 1021 n/m2, which is close to the requirements on the fusion reactor magnets. Irradiation effects at low temperature in superconducting magnet materials should be reviewed to estimate the stability of the superconducting magnet system in operation and its life. The pion capture superconducting solenoids for the COMET experiment are designed with aluminum stabilized superconducting cable to reduce the nuclear heating by neutrons. Also, the heat is designed to be transferred in pure aluminum strips. Irradiation effects on the electrical conductance of aluminum stabilizer and other materials are tested at cryogenic temperature using the reactor neutrons. This paper describes the study on the irradiation effects for the magnet developments. | |||
| THPPD027 | Consolidation of the 13 kA Splices in the Electrical Feedboxes of the LHC | dipole, quadrupole, controls, cryogenics | 3560 |
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| In 2008 a defective connection in one of the 13 kA dipole circuits of the LHC caused an electric breakdown that resulted in extensive damage in a sector of the accelerator. The investigation performed after the accident showed the necessity to consolidate the electrical splices of the 13 kA dipole and quadrupole circuits in order to operate the LHC at its nominal energy of 7 TeV. These circuits are powered through electrical feedboxes located at each end of the 8 sectors of LHC. In the feedboxes the current is routed from room temperature to the superconducting magnets along current leads and superconducting busbars and flows through at least two internal splices. These splices are based on the same technologies as the magnet to magnet ones but they are significantly different in terms of environment and configuration. As for the magnet to magnet splices, a consolidation will be necessary to operate them at nominal current. This paper presents an analysis of the properties of these splices and the technologies that will be used to consolidate them. The quality control provisions and the workflow to perform this operation during the first long shutdown of LHC are also presented. | |||
| THPPD030 | Characterization of a Measurement System for Dynamic Effects in Large-aperture SC Quadrupole Magnets | quadrupole, multipole, insertion, controls | 3569 |
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A new measurement system, based on a large-diameter search-coil rotating in the superfluid helium, a fast digital integrator, a motor drive unit with sliprings, and a flexible software environment was devolped at CERN for the measurement of dynamic effects in superconducting magnets*. This system has made it possible the measure, with a resolution of up to 8 Hz, the multipole field errors due to superconductor magnetization and interstrand coupling currents. In the paper we will present the development and calibration of the measurement system, its installation in the vertical cryostat of CERN's recently refurbished test station, and its application to the US-LARP** built, 120-mm-aperture Nb3Sn quadrupole magnet (HQ) for the upgrade of the LHC insertion regions.
* P. Arpaia et al. Active Comp. of Field Errors within ± 2 PPM in SC Magnets, NIM A, 2011 ** H. Felice et al. Design of HQ, a High Field Large Bore Nb3Sn Quad. Magnet for LARP, IEEE TAS, 2009 |
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| THPPD032 | Consolidation of the LHC Superconducting Circuits: A Major Step towards 14 TeV Collisions | dipole, quadrupole, controls, vacuum | 3575 |
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| Following the incident in one of the main dipole circuits of the Large Hadron Collider (LHC) in September 2008, a detailed analysis of all magnet circuits has been performed by a dedicated task force. This analysis has revealed several critical issues in the design of the 13 kA splices between the main LHC cryomagnets. These splices have to be consolidated before increasing the beam energy above 4 TeV and to operate the LHC close to 7 TeV per beam. The design for the consolidated 13 kA splices is now complete and has been reviewed by an international committee of experts. In the process, all types of superconducting circuits have been thoroughly screened and several important recommendations were established. They were critically assessed and the resulting actions are presented. In addition to the work on the 13 kA splices, other interventions will be performed during the first long shut-down of the LHC to consolidate globally all the superconducting circuits. The associated quality controls have been defined and are detailed in the operations workflow. The schedule constraints, repairs production rate, available space and resources are presented as well. | |||
| THPPD041 | Evaluation and Implementation of High Performance Real-Time Signal Processing For Rayleigh Scattering Based Quench Detection for High Field Superconducting Magnets | solenoid, scattering, LabView, simulation | 3602 |
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Funding: Supported in part by SBIR Grant 4747 · 11SC06251 YBCO coated conductors are one of the primary options for generating the high magnetic fields needed for future high energy physics devices. Due to slow quench propagation, quench detection remains one of the primary limitations to YBCO magnets. Fiber optic sensing, based upon Rayleigh scattering, has the potential for quench detection with high spatial resolution. This paper discusses the potential of multicore CPU's and FPGA’s to accelerate the signal processing demands associated with Rayleigh scattering based quench detection systems in a real-time environment. |
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| THPPR047 | Design of Superconducting Rotating-gantry for Heavy-ion Therapy | simulation, ion, heavy-ion, optics | 4080 |
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| We designed a superconducting rotating-gantry for heavy-ion therapy. This isocentric rotating-gantry can transport heavy ions having 430 MeV/u to the isocenter with irradiation angles between 0-360 degrees, and further has the capability of our fast raster-scanning irradiation, as employed in the existing fixed-irradiation-ports. For the magnets, combined-function superconducting-magnets will be employed. The use of these superconducting magnets allowed us to design the compact gantry, while keeping a sufficient scan size at the isocenter; the length and radius of the gantry would be approximately 13m and 5.5m, respectively, which are comparable to those of the existing proton gantries. Superconducting coils were designed by using the 3D field solver, so as to obtain uniform field distributions. The two superconducting magnets are being constructed. We will present the design of the superconducting gantry as well as details of the superconducting magnets. | |||