Design Considerations of a Pair of Power Leads for Fast-Cycling Superconducting Accelerator Magnets Operating at 2 Tesla and 100 kA

Abstract

Abstract-Recently proposed injector accelerator, Low Energy Ring (LER) for the LHC and fast cycling accelerators for the proton drivers (SF-SPS at CERN and DSF-MR at Fermilab) require that a new magnet technology be developed. In support of this accelerator program, a pair of power leads needs to be developed to close the loop between the power supply and accelerator system. The magnet proposed to be used will be a modified transmission line magnet technology that would allow for accelerator quality magnetic field sweep of 2 T/s. The transmission line conductor will be using HTS technology and cooled with supercritical helium at 5 K. The power leads consist of two sections; upper one is a copper and lower section will be using HTS tapes. The accelerator magnet will be ramped to 100 kA in a second and almost immediately ramped down to zero in one second. This paper outlines the design considerations for the power leads to meet the operational requirements for the accelerator system. The power leads thermal analysis during the magnet powering cycle will be included.

Fast-cycling superconducting synchrotrons and possible path to the future of US experimental high-energy particle physics

“…The higher mass value is mostly from terrestrial experiments while the lower one comes from the solar neutrino studies. In the analysis [2] the most likely values of the mixing angle parameters are also given with sin 2 2θ 13 The neutrino mass can not be directly measured, but as neutrinos pass through the matter they can change the flavor, the process that is described as oscillations. The detection of the oscillations would be a manifestation that neutrinos have mass.…”

“…The detection of the oscillations would be a manifestation that neutrinos have mass. The probability of the oscillation is a function of all the mixing angles and other parameters, so the potential smallness of the sin 2 2θ 13 parameter has a strong impact on the probability of the oscillation, and consequently on the feasibility of the experiment. In addition, the complexity of the oscillation function produces typically up to eight-fold degenerate solutions to the experimental data, adversely affecting oscillation detection thresholds.…”

“…The DSFMR ring will accelerate both batches up to 480 GeV, and then extract them into one or two neutrino beam production lines, as desired. Some technical details of the main arc magnet, current leads and power supply designs were presented in [11,12,13]. Using the Main Ring tunnel for the DSFMR allows re-use the existing Tevatron infrastructure (power distribution, cryogenic support, etc.)…”

“…electron cloud effects [14]. With the N b ~ 10 11 protons per bunch the maximum allowable number of stored protons in the Main Injector is ~5.4 x 10 13 . As the DSFMR ring circumference is double in size of the Main Injector and the beam pipe cross-sections are about the same, one should expect to store ~1.08 x 10 14 protons in each of the DSFMR rings.…”

“…Following the successful development of the VLHC low-field magnet a design effort was initiated for a superconducting transmission line that would be suitable for the fast ramping/fast-cycling magnets. Some preliminary studies of 2 Tesla magnets operating with a 2 T/s ramp rate [11], including the associated power supply [12] and the current leads [13] were recently presented at the MT-20 Conference. It was estimated in [11] that the cryogenic power losses associated with 2 T/s B-field ramping speed would not exceed some 4 kW for an accelerator of 7 km circumference (e.g.…”