Recent studies have shown that strong, alternating focusing magnets can be used to greatly increase the momentum acceptance of hadron therapy gantries. With the high gradients achievable with ...superconducting magnets a level of momentum acceptance can be reached which may have significant implications to medical gantries and to the introduction of superconducting technology in this area. The design of such a superconducting magnet system for a proton therapy gantry will be presented. The Canted-Cosine-Theta concept is extended to a curved magnet system generating the desired bending and alternating focusing fields for the achromatic optics. Magnetic, structural, and thermal analysis of this design is presented along with preliminary efforts towards fabrication and assembly of the curved magnet.
A two-layer subscale canted-cosine-theta 4.5 T has been built and successfully tested. The design of the magnet is based on Nb 3 Sn cable wound into aluminum bronze mandrels, and an external aluminum ...shell. The magnet was conceived as an agile platform for the development of canted-cosine-theta magnets and general magnet technology. The main fabrication, assembly and analysis processes developed for this magnet are discussed in detail. The training behavior and mechanical response of magnet's structure in relation to previous canted-cosine-theta magnets are also discussed.
Canted-Cosine-Theta (CCT) magnet is an accelerator magnet that superposes fields of nested and tilted solenoids that are oppositely canted. The current distribution of any canted layer generates a ...pure harmonic field as well as a solenoid field that can be cancelled with a similar but oppositely canted layer. The concept places windings within mandrel's ribs and spars that simultaneously intercept and guide Lorentz forces of each turn to prevent stress accumulation. With respect to other designs, the need for pre-stress in this concept is reduced by an order of magnitude making it highly compatible with the use of strain sensitive superconductors such as Nb 3 Sn or HTS. Intercepting large Lorentz forces is of particular interest in magnets with large bores and high field accelerator magnets like the one foreseen in the future high energy upgrade of the LHC. This paper describes the CCT concept and reports on the construction of CCT1 a "proof of principle" dipole.
The canted-cosine-theta (CCT) is an advantageous design for high-field superconducting dipoles because of its modular construction and significant reduction in Lorentz-forceinduced conductor stress. ...This is accomplished by introducing layered structural elements within the coilpack to both position the conductor and prevent the accumulation of Lorentz forces. This paper presents 3-D structural analysis of a CCT dipole consisting of four inner layers of Bi2212 high-temperature superconductor (HTS) and eight outer layers of Nb3Sn. Finite-element calculations in ANSYS are shown for configurations with and without the HTS insert. The effectiveness of using mandrels as an internal structure is demonstrated by local conductor stress components of less than 75 MPa in Bi2212 and less than 100 MPa in Nb3Sn with minimal structure external to the coilpack.
High-temperature superconducting <inline-formula><tex-math notation="LaTeX">\rm{REBa}_{2} Cu_{3} O_{7-x}</tex-math></inline-formula> ( REBCO ) conductors have the potential to generate a high ...magnetic field over a broad temperature range. The corresponding accelerator magnet technology, still in its infancy, can be attractive for future energy-frontier particle colliders such as a multi-TeV muon collider. To help develop the technology, we explore the requirements and potential characteristics of a REBCO magnet, operating at 4.2 or 20 K, with a dipole field of 8 - 10 T in a clear aperture of 150 mm. We use the canted <inline-formula><tex-math notation="LaTeX">\cos \theta</tex-math></inline-formula> magnet configuration to reduce the electromagnetic stresses on the conductors. We present the resulting dipole fields, field gradients for combined-function cases, conductor stresses, magnet dimensions and conductor lengths. We also discuss the conductor performance that is required to achieve the target dipole field at 4.2 and 20 K. The information can provide useful input to the development of REBCO magnet and conductor technology for collider-ring magnets in a muon collider.
Future high-energy accelerators will need very high magnetic fields in the range of 20 T. The Enhanced European Coordination for Accelerator Research and Development (EuCARD-2) Work Package 10 is a ...collaborative push to take high-temperature superconductor (HTS) materials into an accelerator-quality demonstrator magnet. The demonstrator will produce 5 T stand alone and between 17 and 20 T when inserted into the 100-mm aperture of a Fresca-2 high-field outsert magnet. The HTS magnet will demonstrate the field strength and the field quality that can be achieved. An effective quench detection and protection system will have to be developed to operate with the HTS superconducting materials. This paper presents a ReBCO magnet design using a multistrand Roebel cable that develops a stand-alone field of 5 T in a 40-mm clear aperture and discusses the challenges associated with a good field quality using this type of material. A selection of magnet designs is presented as the result of the first phase of development.
The Canted-Cosine-Theta (CCT) magnet design offers significant reductions in conductor stress by using mandrels to prevent the accumulation of operating Lorentz forces. Each mandrel consists of a ...cylindrical spar with ribs guiding the conductor. These ribs intercept the turn-to-turn accumulation of forces by transferring them to the spar. Design studies of a layered CCT coil pack coupled to a shell-based structure are shown. The use of a 3-D periodic symmetry region to reduce the problem size for finite element modeling is detailed along with a discussion of axial boundary conditions. ANSYS calculation results for a two layer NbTi dipole being constructed at LBNL (CCT1) are presented. ANSYS calculations show the Lorentz force induced stress in CCT1 at the single turn level, demonstrating interception and suggesting investigation of CCT design with minimal structure external to the coil pack.
A multilayer high field dipole magnet has been designed for future particle accelerators. The magnet has eight layers of a Nb 3 Sn outsert coil and four layers of a Bi-2212 insert coil (see Figs. 1 ...and 2). The layers are graded, delivering a short-sample field of 17.7 T in a 40-mm bore. The coil layers are of a canted cosine-theta design-with ribs and spars that guide and support the coil windings, shape the field, intercept Lorentz forces, and minimize conductor prestress. We present a general overview of the concept and report on the magnetic and mechanical design including an initial cost estimate and construction plan.
Cost-effective design for a neutrino factory Berg, J. S.; Bogacz, S. A.; Caspi, S. ...
Physical review special topics. PRST-AB. Accelerators and beams,
01/2006, Letnik:
9, Številka:
1
Journal Article
Recenzirano
Odprti dostop
There have been active efforts in the U.S., Europe, and Japan on the design of a neutrino factory. This type of facility produces intense beams of neutrinos from the decay of muons in a high-energy ...storage ring. In the U.S., a second detailed feasibility study (FS2) for a neutrino factory was completed in 2001. Since that report was published, new ideas in bunching, cooling, and acceleration of muon beams have been developed. We have incorporated these ideas into a new facility design, which we designate as study 2B (ST2B), that should lead to significant cost savings over the FS2 design.
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