The Fermilab Mu2e experiment seeks to measure the rare process of direct muon to electron conversion in the field of a nucleus. The experiment makes use of three large superconducting solenoids: the ...production solenoid (PS), the transport solenoid (TS), and the detector solenoid (DS). The TS is an "S-shaped" solenoid with a warm-bore aperture of half a meter and field between 2.5 and 2.0 T. The three solenoids are based on four different types of Al stabilized NbTi conductors. All the conductors are composed of a Rutherford cable embedded in an aluminum matrix through a conforming process. This paper describes the various steps that led to the successful procurement of 3 km of Al-stabilized prototype cable for the Mu2e TS. The main cable properties and results of electrical and mechanical tests are presented and discussed for each stage of the cable development process. Results are compared to design values to show how the prototype cable lengths satisfied all the design criteria starting from the NbTi wires all the way to the Al-stabilized cables. Following the successful completion of this initial phase, the TS prototype cable is currently being used to manufacture a prototype TS coil in industry. The cable production phase has recently been launched, with the goal of producing 700 km of superconducting wire for a total of 44 km of TS Al-stabilized cable needed to build the entire Transport Solenoid system.
Test Results of the LARP HQ02b Magnet at 1.9 K Bajas, H.; Ambrosio, G.; Anerella, M. ...
IEEE transactions on applied superconductivity,
06/2015, Letnik:
25, Številka:
3
Journal Article
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The HQ magnet is a 120-mm aperture, 1-m-long Nb 3 Sn quadrupole developed by the LARP collaboration in the framework of the High-Luminosity LHC project. A first series of coils was assembled and ...tested in five assemblies of the HQ01 series. The HQ01e model achieved a maximum gradient of 170 T/m at 4.5 K at LBNL in 2010-2011 and reached 184 T/m at 1.9 K at CERN in 2012. A new series of coils incorporating major design changes was fabricated for the HQ02 series. The first model, HQ02a, was tested at Fermilab where it reached 98% of the short sample limit at 4.5 K with a gradient of 182 T/m in 2013. However, the full training of the coils at 1.9 K could not be performed due to a current limit of 15 kA. Following this test, the azimuthal coil pre-load was increased by about 30 MPa and an additional current lead was installed at the electrical center of the magnet for quench protection studies. The test name of this magnet changed to HQ02b. In 2014, HQ02b was then shipped to CERN as the first opportunity for full training at 1.9 K. In this paper, we present a comprehensive summary of the HQ02 test results including: magnet training at 1.9 K with increased preload; quench origin and propagation; and ramp rate dependence. A series of powering tests was also performed to assess changes in magnet performance with a gradual increase of the MIITs. We also present the results of quench protection studies using different setting for detection, heater coverage, energy extraction and the coupling-loss induced quench (CLIQ) system.
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.
Indirect searches have the potential to probe scales beyond the realm of direct searches. In this paper, we consider the implications of two parity violating experiments: weak charge of proton QWp ...and the Caesium atom QWCs on the solutions to lepton flavor nonuniversality violations in the decay of B mesons. Working in a generic implementation of a minimal Z′ model, we assume the primary contribution being due to the electron to facilitate comparison with the low q2 parity violating experiments. We demonstrate that the conclusion is characterized by different limiting behavior depending on the chirality of the lepton current. The correlation developed in this study demonstrates the effectiveness in studying the synergy between different experiments leading to a deeper understanding of the interpretation of the existing data. It is shown that a possible future improvement in the parity violating experiments can have far reaching implications in the context of direct searches. We also comment on the prospect of addition of the muon to the fits and the role it plays in ameliorating the constraints on models of Z′. This offers a complimentary understanding of the pattern of the coupling of the new physics to the leptons, strongly suggesting either a muon only or a combination of solutions to the anomalies.
The management of heart failure with reduced ejection fraction (HF-REF) has improved significantly over the last two decades. In contrast, little or no progress has been made in identifying ...evidence-based, effective treatments for heart failure with preserved ejection fraction (HF-PEF). Despite the high prevalence, mortality, and cost of HF-PEF, large phase III international clinical trials investigating interventions to improve outcomes in HF-PEF have yielded disappointing results. Therefore, treatment of HF-PEF remains largely empiric, and almost no acknowledged standards exist. There is no single explanation for the negative results of past HF-PEF trials. Potential contributors include an incomplete understanding of HF-PEF pathophysiology, the heterogeneity of the patient population, inadequate diagnostic criteria, recruitment of patients without true heart failure or at early stages of the syndrome, poor matching of therapeutic mechanisms and primary pathophysiological processes, suboptimal study designs, or inadequate statistical power. Many novel agents are in various stages of research and development for potential use in patients with HF-PEF. To maximize the likelihood of identifying effective therapeutics for HF-PEF, lessons learned from the past decade of research should be applied to the design, conduct, and interpretation of future trials. This paper represents a synthesis of a workshop held in Bergamo, Italy, and it examines new and emerging therapies in the context of specific, targeted HF-PEF phenotypes where positive clinical benefit may be detected in clinical trials. Specific considerations related to patient and endpoint selection for future clinical trials design are also discussed.
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