superconducting-magnet

Paper	Title	Other Keywords	Page
MOXBCH01	Industrial Technology for Unprecendented Energy and Luminosity: the Large Hadron Collider	dipole, luminosity, collider, cryogenics	6
	P. Lebrun CERN, Geneva
	With over 2.7 billion Swiss francs procurement contracts under execution in industry and the installation of major technical systems proceeding in its first 3.3 km sector, the Large Hadron Collider (LHC) construction is now in full swing at CERN, the European Organization for Nuclear Research. The LHC is not only the most challenging particle accelerator under construction, it is also the largest global project ever for a scientific instrument based on advanced technology. Starting from accelerator performance requirements, we recall how these can be met by an appropriate combination of technologies, such as high-field superconducting magnets, superfluid helium cryogenics, beam and insulation vacuum or power electronics, with particular emphasis on the developments required to meet demanding specifications, and the industrialization issues which had to be solved for achieving series production of precision components under tight quality assurance and within limited resources. This provides the opportunity for reviewing the production status of the different systems and the progress of the project.
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MOPLT030	Performance Limits and IR Design of a Possible LHC Luminosity Upgrade Based on Nb-Ti SC Magnet Technology	quadrupole, luminosity, radiation, insertion	608
	F. Ruggiero, O.S. Brüning, R. Ostojic, L. Rossi, W. Scandale, T.M. Taylor CERN, Geneva A. Devred CEA/DSM/DAPNIA, Gif-sur-Yvette
	We investigate the maximum LHC performance for a possible IR design based on classical Nb-Ti insertion magnets. We then extend our analysis to a ternary Nb-based ductile alloy such as Nb-Ti-Ta, a less developed but relatively cheap super-conducting material which would allow us to gain about 1 T of peak field on the coils, and discuss the corresponding luminosity reach for a possible LHC upgrade compared to that based on Nb3Sn magnet technology.
MOPLT115	Numerical Simulations and Analyses of Beam-Induced Damage to the Tevatron Collimators	simulation, proton, dipole, collimation	806
	A. Drozhdin, N. Mokhov, D. Still Fermilab, Batavia, Illinois V. Samulyak BNL, Upton, Long Island, New York
	Numerical simulations are performed to analyze the Tevatron collimator damage happened in December 2003 that was induced by a failure in the CDF Roman Pot detector positioning during the collider run. Possible scenarios of this failure resulted in an excessive halo generation and superconducting magnet quench are studied via realistic simulations using the STRUCT and MARS14 codes. It is shown that the interaction of a misbehaved proton beam with the collimators result in a rapid local heating and a possible damage. A detailed consideration is given to the ablation process for the collimator material taking place in high vacuum. It is shown that ablation of tungsten (primary collimator) and stainless steel (secondary collimator) jaws results in creation of a groove in the jaw surface as was observed after the December's accident.
WEXCH01	Experience with LHC Magnets from Prototyping to Large-scale Industrial Production and Integration	dipole, target, quadrupole, sextupole	118
	L. Rossi CERN, Geneva
	The construction of the LHC superconducting magnets is approaching one third of its completion. At the end of 2003, main dipoles cold masses for more than one octant were delivered; meanwhile the winding for the second octant was almost completed. The other big magnets, like the main quadrupoles and the insertion quadrupoles, have entered into series production as well. Providing more than 20 km of superconducting magnets, with the quality required for an accelerator like LHC, is an unprecedented challenge in term of complexity that has required several steps from the construction of 1 meter-long magnets in the laboratory to today production of more than one 15 meter-long magnet per day in Industry. The work and its organization is made even more complex by the fact that CERN supplies most of the critical components and part of the main tooling to the magnet manufacturers, both for cost reduction and for quality issues. In this paper the critical aspects of the construction and the time plan will be reviewed and the actual achievements in term of quality and construction time will be compared with the expectations.
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WEPKF010	Design of an Automatic System for the Electrical Quality Assurance during the Assembly of the Electrical Circuits of the LHC	instrumentation, dipole, sextupole, quadrupole	1612
	D. Bozzini, V. Chareyre, A. Jacob, K.H. Mess, S. Russenschuck, R. Solaz Cerdan CERN, Geneva
	During the assembly of the LHC one of the challenges will be the correct wiring of the 1712 circuits powering the 10094 magnet units, for which all-together 70000 splices have to be done. Considering the complexity of the electrical scheme the risk of wrong wiring is high. Errors, if not detected during the assembly phase, will perturb the LHC operation. A method has been developed to verify automatically the cabling scheme. It first detects the continuity of a portion of circuit and then verifies the correct polarity and type of the magnets in the circuit. A 108-meter LHC cell is the shortest length that can be tested. The system is composed of a unit to be placed at the center of the cell and two de-multiplexers positioned at the extremities of the cell. The central unit contains a data acquisition system where in total 217 signals can be acquired and more than 3000 voltage combinations are possible. Pointing to different databases, a LabVIEW program automatically executes the test procedure, generates, and stores the reports. The hardware and software design, the data flow between databases, and the testing methodology applied to the different circuit types are described.
WEPKF021	Non-destructive Testing of Bus-bar Joints Powering LHC Superconducting Magnets, by Using Gamma Sources	quadrupole, dipole, photon, target	1642
	B. Skoczen CERN, Geneva J. Kulka AGH, Cracow
	The main LHC superconducting magnets (dipoles and quadrupoles) are powered by using Rutherford type cables, stabilized electrically and thermally with copper profiles. The portions of cables are connected to each other by a soft soldering technique (Sn96Ag4) with the overlapping length corresponding to one pitch of the superconducting strands. The splice constitutes a ?composite? structure with the interchanging layers of Sn96Ag4 and NbTi superconductor, located inside a Cu cage. In order to assure a high level of reliability (failure probability not exceeding 10-8) for some 10000 connections in the LHC, a non-destructive technique of checking the quantity of solder in the joint is planned to be implemented. The technique is based on a gamma ray source (241_Am) and the detection is position-sensitive in the transmission mode. 5 scintillating detectors of gamma rays are used and their accumulated length corresponds to the length of the radioactive source (120 mm). The method can be used in-situ, the equipment being optimized and portable, with implementation of direct on-line operation mode. The relevant criteria of acceptance of the splices have been defined. The first results of application of this technique will be shown.
WEPKF061	Study of Electrical Steel Magnetic Properties for Fast Cycling Magnets of SIS100 and SIS300 Rings	dipole, induction, power-supply, pick-up	1741
	I. Bogdanov, S. Kozub, A. Shcherbakov, L. Tkachenko IHEP Protvino, Protvino, Moscow Region E. Fischer, F. Klos, G. Moritz, C. Muehle GSI, Darmstadt
	The operation conditions of yoke steels in superconducting magnets of the SIS100 and SIS300 are at 4.2 K and unipolar cycles with high magnetic induction. The results of measurements of different classes of electrical steels, both isotropic and anisotropic, in the operating conditions of superconducting dipoles are presented. The measurements are carried out on ring samples in quasistatic mode. Dependence of B(H) as well as values of Hc and hysteresis losses in bipolar and unipolar cycles are determined from hysteresis loops at different temperatures. The anisotropy of steels is measured at room temperature on the strip samples, cut along the rolling direction and across one. The comparison of results on ring and strip samples is carried out. The results of calculations of hysteresis and eddy current losses in iron yoke of fast-cycling dipole for the SIS300 are presented. The recommendations on choice of grade steels for fast cycle superconducting magnets are given.
WEPKF062	Study of the Quench Process in Fast-cycling Dipole for the SIS300 Ring	dipole, power-supply, simulation, dumping	1744
	I. Bogdanov, S. Kozub, A. Shcherbakov, L. Tkachenko, S. Zintchenko, V. Zubko IHEP Protvino, Protvino, Moscow Region J. Kaugerts, G. Moritz GSI, Darmstadt
	The results of numerical quench process simulation in the coil of superconducting dipole with magnetic field of 6 T and 100-mm aperture for high-energy ion and proton synchrotron facility SIS300 are presented. The peculiarities of quench process developed in dipole are discussed for several variants of quench conditions. The coil quench behavior determines the features, scopes, and limitations in possible quench protection scheme. Main design characteristics of the preferable protection system are considered.
WEPKF065	Study of Thermal Stability and Quench Process of HTS Dipole	dipole, superconductivity, simulation, magnet-design	1753
	V. Zubko, I. Bogdanov, S. Kozub, A. Shcherbakov, L. Tkachenko IHEP Protvino, Protvino, Moscow Region
	The dipole with a coil made from HTS composite on a Bi2223 basis and placed in the ferromagnetic yoke has been developed and produced in IHEP. A designed magnetic field of the dipole in 20-mm aperture is 1 T at temperature of liquid nitrogen. The numerical analysis of factors, having influence on thermal stability of the magnet, as well as the computer simulations of dipole heating during quench was carried out. An anisotropy of voltage-current characteristics of HTS tapes in a magnetic field is taken into account in calculations of quench process. The measured results of voltage-current characteristics during powering and quench of the coil are in a good agreement with the numerical calculations
WEPKF066	Stability of Fast-cycling Dipole for SIS300 Ring	dipole, coupling, simulation, lattice	1756
	V. Zubko, I. Bogdanov, S. Kozub, A. Shcherbakov, L. Tkachenko, S. Zintchenko IHEP Protvino, Protvino, Moscow Region M. Kauschke, G. Moritz GSI, Darmstadt
	Funding AgencyShould not exceed 200 charactersFootnotesFootnotes: Not exceeding 200 chaThe main requirement to the superconducting dipole with 100-mm aperture, 6-T magnetic field amplitude and 1-T/s field ramp rate for the SIS300 accelerator, developed in the GSI, Darmstadt, is a stability of the magnet influenced by various heat releases arising during operation mode. The computer simulation of the heating of superconducting dipoles and cooling helium during the SIS300 operating cycle was carried out. The analysis of stability is based on the numerical solution of the heat balance equation in the coil and in a single?phase helium flow. Temperature margin of the superconducting dipole during the SIS300 operating cycle was calculated. Possible ways to increase the temperature margin are discussed.
WEPKF070	Design Issues for the Superconducting Magnet that goes around the Liquid Hydrogen Absorber for the Muon Ionization Cooling Experiment (MICE)	vacuum, focusing, magnet-design, radiation	1765
	M.A. Green, G. Barr, J. Cobb, W. Lau, R.S. Senanayake, H. Witte, S.Q. Yang OXFORDphysics, Oxford, Oxon E. Baynham, T.W. Bradshaw, P. Drumm, Y. Ivanyushenkov, J. Rochford CCLRC/RAL, Chilton, Didcot, Oxon
	This report describes the design issues that are associated with a superconducting focusing solenoid that goes around a liquid hydrogen absorber for the Muon Ionization Cooling Experiment (MICE) proposed for the Rutherford Appleton Laboratory. The solenoid consists of two superconducting coils that may operated at the same polarity or at opposite polarities. As a result, the coils and their support structure must be designed to carry a 300 ton inter-coil force that is forcing the coils apart along their axis. The basic design parameters for the focusing magnet are discussed. The magnet and its cryostat are designed so that the absorber can be assembled and tested before installation into the pre-tested focusing solenoid. A safety requirements for MICE dictate that the insulating vacuum for the superconducting magnet be separated from the insulating vacuum for the absorber and that both vacuum be separated from the experiment vacuum and the vacuum within adjacent RF cavities. The safety issues associated with the arrangement of the various vacuums in the MICE focusing modules are presented. The effect of magnet operation and magnet quench on the liquid hydrogen absorber is also discussed.
WEPKF086	A Model for Determining Dipole, Quadrupole and Combined Function Magnet Costs	dipole, quadrupole, linac, diagnostics	1807
	R. Palmer, J.S. Berg BNL, Upton, Long Island, New York
	One of the most important considerations in designing large accelerators is cost. Magnet costs are a significant component of that. This paper describes a model for estimating magnet costs. The reasoning behind the cost model is explained, and the parameters of the model are chosen so as to correctly give the costs for existing magnets.
THPLT170	Finding the Circular Magnet Aperture which Encloses an Arbitrary Number of Midplane-centered Beam Ellipses	closed-orbit, coupling, lattice	2858
	J.S. Berg BNL, Upton, Long Island, New York
	In specifying the magnets for an accelerator, one must be able to determine the aperture required by the beam. In some machines, in particular FFAGs, there is a significant variation in the closed orbit and beta functions over the energy range of the machine. In addition, the closed orbit and beta functions may vary with the longitudinal position in the magnet. It is necessary to determine a magnet aperture which encloses the beam ellipses at all energies and all positions in the magnet. This paper describes a method of determining the smallest circular aperture enclosing an arbitrary number of midplane-centered ellipses.