| Paper | Title | Other Keywords | Page |
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| MOPEA026 | Update on the Innovative Carbon/Proton Non-scaling FFAG Isocentric Gantries for the Cancer Therapy | proton, ion, focusing, betatron | 124 |
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There is a dramatic increase in number of proton/carbon cancer therapy facilities in recent years due to their clear advantage over other radiation therapy treatments. The cost of ion cancer therapy is still prohibitive for most of the hospitals, and the dominant costs are beam delivery systems. We previously presented designs of carbon and proton isocentric gantries using non-scaling alternating gradient fixed field magnets (NS-FFAG) *, where gantry magnet size and weight are dramatically reduced. The weight of the transport elements of our NS-FFAG carbon isocentric gantry is 1.5 tons compared to 130 ton gantries recently constructed Heidelberg C facility at Heidelberg. We have also designed a proton NS-FFAG permanent magnet gantry with an estimated weight of 500 kg. We present an update on these designs. * D. Trbojevic, B. Parker, E. Keil, and A. M. Sessler, |
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| MOPEB033 | Operation of Superconducting Combined Function Magnet System for J-PARC Neutrino Beam Line | dipole, quadrupole, proton, cryogenics | 343 |
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A superconducting magnet system for the J-PARC neutrino beam line was completed at the end of 2008. The system consists of 14 doublet cryostats; each contains 2 combined function magnets (SCFM). The SCFM uses two single layer left/right asymmetric coils that produce a dipole field of 2.6 T and quadrupole of 19 T/m. By 2008, the world first SCFM had been developed and tested successfully at KEK. The mass-production was started in 2005, and completed by summer 2008. The system installation and commissioning took place from Feb. 2008 to Mar. 2009. The beam operation was started in April 2009 and the first neutrino beam was generated on April 23rd. Since then beam operation and commissioning to increase beam intensity has been performed to achieve the near term milestone of 100 kW beam operation. The paper briefly summarizes the history of SCFM development and the system construction as an introduction to a discussion on beam operation experience of the SCFM system. |
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| MOPEB038 | Design and Manufacture of Superconducting Magnet for the Wiggler in SAGA-LS | wiggler, electron, synchrotron, vacuum | 358 |
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A 4T superconducting wiggler for 1.4GeV synchrotron radiation facility Saga Light Source (SAGA-LS) was developed and manufactured. The wiggler consists of one superconducting magnet as main-pole and two normal conducting magnets as side-poles. The superconducting coils are wound with NbTi wires on iron poles, which are directly cooled by a 2-stage GM cryocooler. The structure of the wiggler is made for compactness and cryogen-free operation. This paper describes its magnet design and manufacturing processes. |
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| MOPEB043 | New Techniques for Mechanical Measurements in the Superconducting Magnet Models | monitoring, dipole, instrumentation, alignment | 370 |
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Force transducers based on strain and capacitive gauges have been developed and used for monitoring the coil pre-stress during assembly and excitation of magnet models. This paper will summarize and compare the new techniques of mechanical measurements use at CERN for the New Inner Triplet Project. Furthermore the paper will give a comparison of the gauge performances (Creep effects, temperature effects, etc.) and will present the performances of the new data acquisition system developed at CERN to measure simultaneously the strain gauges, the capacitive gauges and other external parameters for the magnet. |
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| MOPEB057 | Roebel Cable for High-field Low-loss Accelerator Magnets | superconductivity, status, background, magnet-design | 397 |
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High field accelerator magnets are needed for high energy physics applications. Superconducting materials able to reach these fields with low losses are required, and YBCO Roebel cable is being developed to address this issue. Characterization of commercially available Roebel cables for high field low temperature superconducting magnets is needed. YBCO Roebel cable with low AC losses is being developed and has limited commercial availability. Its behavior is not fully understood, however, especially in liquid helium and at high magnetic fields. YBCO Roebel cable will be acquired from a commercial vendor and characterized at cryogenic temperatures, in varying magnetic fields, and different strain configurations. A comprehensive behavior analysis will be performed, including operational and fatigue limits. Characterization of YBCO Roebel cable at low temperatures will be performed, including determination of the current flow path in steady-state and during quench using magneto-optical imaging, investigation of the effects of strand insulation, and examination of the mechanical and quench behavior at 4.2 K, 77 K, and varying magnetic fields. |
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| MOPEB076 | Mobile CT-System for In-situ Inspection in the LHC at CERN | controls, vacuum, radiation, diagnostics | 447 |
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For the inspection of certain critical elements of the LHC machine a mobile computed tomography system has been developed and built. This instrument has to satisfy stringent space, volume and weight requirements in order to be usable and transportable to any interconnection location in the LHC tunnel. Particular regions of interest in the interconnection zones between adjacent magnets are the plug in modules (PIM), the soldered splices in the superconducting bus-bars and the interior of the quench diode container. This system permits detailed inspection of these regions without needing to break the cryo vacuum. Limited access for the x-ray tube and the detector required the development of a special type of partial tomography, together with suitable reconstruction techniques for 3 D volume generation from radiographic projections. We present the layout of the complete machine and the limited angle tomography as well as a number of radiographic and tomographic inspection results. |
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| TUPEA082 | Versatile Device for In-situ Discharge Cleaning and Multiple Coatings of Long, Small Diameter Tubes | cathode, electron, plasma, vacuum | 1509 |
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Electron clouds, which can limit machine performance, have been observed in many accelerators including RHIC at BNL. They can be suppressed by low secondary electron yield beam pipe surfaces. Additional concern for the RHIC machine, whose vacuum chamber is made from relatively high resistivity 316LN stainless steel, is high wall resistivity that can result in unacceptably high ohmic heating for superconducting magnets. The high resistivity can be addressed with a copper (Cu) coating; a reduction in the secondary electron yield can be achieved with a TiN or amorphous carbon (a-C) coating. Applying such coatings in an already constructed machine is rather challenging. We started developing a robotic plasma deposition technique for in-situ coating of long, small diameter tubes. The technique entails fabricating a device comprising of staged magnetrons mounted on a mobile mole for deposition of about 5 μm (a few skin depths) of Cu followed by about 0.1 μm of a-C. As a first step, a 15-cm Cu cathode magnetron is being designed and fabricated, after which, 30-cm long sample of the RHIC pipe are to be Cu coated. Deposition rates and affects on RF resistivity are to be measured. |
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| WEPD070 | High Precision Current Control for the LHC Main Power Converters | controls, quadrupole, fibre-optics, dipole | 3260 |
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The LHC was restarted on the 20th of November 2009 after 14 months of shutdown. The machine is composed of 8 powering sectors, each containing a main dipole circuit and two main quadrupole circuits. Each of these main circuits is entirely independent. To operate the LHC, the magnetic fields in the main magnets must be controlled with unprecedented accuracy. Indeed, the current in each power converter must be controlled with an accuracy of a few ppm (parts per million of nominal current) and the currents must be perfectly synchronised between sectors. To achieve the performance required of the LHC power converters, many challenges have been resolved. These include: measuring the power converter currents with an extreme absolute precision, control of these currents without tracking error or overshoot, perfect synchronisation of the current references sent to the power converters of the 24 main circuits. This paper details how these various problems have been resolved to obtain the performance required. Many experimental results are included, in particular the results of the tracking tests performed with the main circuits of the LHC. |
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| THPEA073 | Operational Experience with the LHC Superconducting Links and Evaluation of Possible Cryogenic Schemes for Future Remote Powering of Superconducting Magnets | cryogenics, power-supply, radiation, controls | 3840 |
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In the LHC, a large number of superconducting magnets are powered remotely by 5 superconducting links at distances of 70 up to 540 m. This innovation allowed to choose more convenient locations for installing the electrical feedboxes and their related equipment. The consolidations performed after the first commissioning campaign and the operational experience with the superconducting links over a period of several months are presented. Based on the successful application of superconducting links in the LHC, such devices can be envisaged for powering future accelerator magnets. Several possible cryogenic configurations for future superconducting links are presented with their respective figures of merit from the cryogenic and practical implementation point of view. |