In order to partially compensate for head-on beam-beam effects from polarized proton collisions in the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (BNL), two electron ...lenses (e-Lens) have been manufactured at BNL. For each e-Lens, one for each of the two RHIC rings, a low energy electron beam and the high energy proton beam will interact in a 2.5-m-long superconducting solenoid, which is also accompanied by four other smaller solenoids and 12 corrector dipoles, all of which are superconducting and provide various tuning and corrective functions during operations. The design of this multicoil assembly is a unique and complex one, and likewise, the simultaneous operation of the coils at 4.5 K is also challenging, due to high inductance and individual magnetic fields, which interact with each other. This paper reports on the results from extensive ramp and quench tests at 4.5 K, and the proper operating procedures determined from these tests.
In December 2009 during its first cold test, LQS01, the first Long Nb 3 Sn Quadrupole made by LARP (LHC Accelerator Research Program, a collaboration of BNL, FNAL, LBNL and SLAC), reached its target ...field gradient of 200 T/m. This target was set in 2005 by the US Department of Energy, CERN and LARP, as a significant milestone toward the development of Nb 3 Sn quadrupoles for possible use in LHC luminosity upgrades. LQS01 is a 90 mm aperture, 3.7 m long quadrupole using Nb 3 Sn coils. The coil layout is equal to the layout used in the LARP Technological Quadrupoles (TQC and TQS models). Pre-stress and support are provided by a segmented aluminum shell pre-loaded using bladders and keys, similarly to the TQS models. After the first test the magnet was disassembled, reassembled with an optimized pre-stress, and reached 222 T/m at 4.5 K. In this paper we present the results of both tests and the next steps of the Long Quadrupole R&D.
A magnetic trap for antihydrogen confinement Bertsche, W.; Boston, A.; Bowe, P.D. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
10/2006, Letnik:
566, Številka:
2
Journal Article
Recenzirano
The goal of the ALPHA collaboration at CERN is to test CPT conservation by comparing the 1S–2S transitions of hydrogen and antihydrogen. To reach the ultimate accuracy of 1 part in
10
18
, the ...(anti)atoms must be trapped. Using current technology, only magnetic minimum traps can confine (anti)hydrogen. In this paper, the design of the ALPHA antihydrogen trap and the results of measurements on a prototype system will be presented. The trap depth of the final system will be 1.16
T, corresponding to a temperature of 0.78
K for ground state antihydrogen.
A copper coil dipole magnet from the National Synchrotron Light Source (NSLS) at Brookhaven National Laboratory (BNL) has been retrofitted by HTS-110 Ltd with coils made from Bi-2223 wire and a ...self-contained cryogenic cooling system, while keeping the magnet's original iron yoke. This modified bending dipole, which is the first such known retrofit HTS-based accelerator magnet, provides the benefits of a compact coil design to accommodate space-limited experimental issues and a significant reduction in power costs as compared to the original copper magnet. In order to validate this modified design for use in the synchrotron, a detailed magnetic field map has been measured using a multiple-Hall probe assembly and transporter system. The results are discussed in this paper, along with the performance of the closed circuit cryogenics system in keeping the coils below 45 K.
The RHIC magnet system Anerella, M; Cottingham, J; Cozzolino, J ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
03/2003, Letnik:
499, Številka:
2
Journal Article
Recenzirano
The magnet system of the collider consists of superconducting dipole, quadrupole and correction magnets for guiding and focusing the beams through the regular arcs of the machine lattice as well as ...into collision at the six interaction points. It is designed to allow operation in the energy range 30–100
GeV/
u. Operation with either equal or unequal ion species in the colliding beams is possible, imposing a ratio of up to 2.5:1 in the magnetic fields of the two rings. There are 1740 superconducting magnets in the machine. They were designed to meet stringent requirements on field quality, reproducibility, and long-term reliability while being inexpensive to produce. Wherever feasible, production of magnets and components was carried out in industry, always with build-to-print designs. After several years of operation, no magnet has failed and the magnet system has proven reliable and functional.
After the successful test of the first long Nb 3 Sn quadrupole magnet (LQS01), the US LHC Accelerator Research Program (LARP) has assembled and tested a new 3.7 m-long Nb 3 Sn quadrupole (LQS02). ...This magnet has four new coils made of the same conductor as LQS01 coils, and it is using the same support structure. LQS02 was tested at the Fermilab Vertical Magnet Test Facility with the main goal to confirm that the long models can achieve field gradient above 200 T/m, LARP target for 90-mm aperture, as well as to measure the field quality. These long models lack some alignment features and it is important to study the field harmonics. Previous field quality measurements of LQS01 showed higher than expected differences between measured and calculated harmonics compared to the short models (TQS) assembled in a similar structure. These differences could be explained by the use of two different impregnation fixtures during coil fabrication. In this paper, we present a comparison of the field quality measurements between LQS01 and LQS02 as well as a comparison with the short TQS models. If the result supports the coil fabrication hypothesis, another LQS assembly with all coils fabricated in the same fixture will be produced for understanding the cause of the discrepancy between short and long models.
SuperKEKB beam final focus superconducting magnet system Ohuchi, N.; Arimoto, Y.; Akai, K. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
01/2022, Letnik:
1021
Journal Article
Recenzirano
Odprti dostop
The SuperKEKB was designed and constructed as the upgraded accelerator of KEKB. In this accelerator design, the nano-beam scheme of collision was applied and a luminosity of 8 × 1035 cm−2s−1 was ...targeted. In the design, the beam final focus system was the key component in the accelerator hardware elements. This final focus system consists of 55 superconducting magnets. In this paper, the designs of the magnets, the cryostats and the cryogenic system are shown, and the field measurement results are reported. The SuperKEKB beam operation with the final focus system started on 2018 March 19, and the magnet quench events up to 2020 December 16 are described.
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