33 research outputs found
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Developmentof the 15 T Nb3Sn dipole HD2
The Superconducting Magnet Program at Lawrence Berkeley National Laboratory (LBNL) is continuing the development of HD2, a 1 m long Nb{sub 3}Sn dipole generating a dipole field of 15 T in a 36 mm clear bore. With tilted (flared) ends to avoid obstructing the beam path, HD2 represents a step towards the development of cost effective accelerator quality magnets. The design has been optimized to minimize geometric harmonics and to address iron saturation and conductor magnetization effects. The support structure is based on an external aluminum shell, pre-tensioned with pressurized bladders and interference keys. Aluminum axial rods and stainless steel end plates provide longitudinal support to the coil ends during magnet excitation. This paper reports on field quality optimization and magnet parameters. The design and fabrication of the coil and structure components, and results from coil winding, reaction, and potting are also presented
Measured Strain of Nb3Sn Coils During Excitation and Quench
The strain in a high field Nb{sub 3}Sn coil was measured during magnet assembly, cool-down, excitation and spot heater quenches. Strain was measured with a full bridge strain gauge mounted directly over the turns and impregnated with the coil. Two such coils were placed in a ''common coil'' fashion capable of reaching 11T at 4.2K. The measured steady state strain in the coil is compared with results obtained using the FEM code ANSYS. During quenches, the transient strain (due to temperature rise) was also measured and compared with the calculated mechanical time response to a quench
Disasters and History
Disasters and History offers the first comprehensive historical overview of hazards and disasters. Drawing on a range of case studies, including the Black Death, the Lisbon earthquake of 1755 and the Fukushima disaster, the authors examine how societies dealt with shocks and hazards and their potentially disastrous outcomes. They reveal the ways in which the consequences and outcomes of these disasters varied widely not only between societies but also within the same societies according to social groups, ethnicity and gender. They also demonstrate how studying past disasters, including earthquakes, droughts, floods and epidemics, can provide a lens through which to understand the social, economic and political functioning of past societies and reveal features of a society which may otherwise remain hidden from view
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Construction and Test of 3.5 m Nb3Sn Racetrack Coils for LARP.
Development of high-performance Nb{sub 3}Sn quadrupoles is one of the major goals of the LHC Accelerator Research Program (LARP). As part of this program, long racetrack magnets were made in order to check the fabrication steps for long Nb{sub 3}Sn coils, that the changes in coil length that take place during reaction and cooldown are correctly accounted for in the quadrupole design, and the use of a long aluminum shell for the support structure. This paper reports the construction of the first long Nb{sub 3}Sn magnet with racetrack coils 3.6 m long. The magnet reached a nominal 'plateau' at 9596 A after five quenches. This is about 90% of the estimated conductor limit. The peak field in the coils at this current was 11 T
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Structure for a 90mm Nb3Sn cosine-2 theta IR quadrupole magnet
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Progress in Wind-and-React Bi-2212 Accelerator Magnet Technology
We report on our progress in the development of the technology for the application of Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+x}(Bi-2212) in Wind-and-React accelerator magnets. A series of superconducting subscale coils has been manufactured at LBNL and reacted at the wire manufacturer SWCC. Selected coils are impregnated and tested in self-field, even though the coils exhibited leakage during the partial melt heat treatment. Other coils have been disassembled after reaction and submitted to critical current (Ic) tests on individual cable sections. We report on the results of the current carrying capacity of the coils. Voltage-current (VI) transitions were reproducibly measured up to a quench currents around 1400 A, which is 25% of the expected performance. The results indicate that the coils are limited by the inner windings. We further compare possibilities to use Bi-2212 and Nb{sub 3}Sn tilted solenoid, and YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} (YBCO) racetrack inserts to increase the magnetic field in HD2, a 36 mm bore Nb{sub 3}Sn dipole magnet which recently achieved a bore magnetic field of 13.8 T. The application of Bi-2212 and/or YBCO in accelerator type magnets, if successful, will open the road to higher magnetic fields, far surpassing the limitations of Nb{sub 3}Sn magnet technology