A 15 T Nb 3 Sn dipole, MDPCT1, with cos-theta-type coils was developed to demonstrate a possible magnet design for a post-LHC proton-proton Collider. The magnet has 4-layer coils with 60-mm aperture, and has graded current density between the inner and outer layers to maximize performance. The coils are constrained by vertically-split, thick iron laminations, connected by aluminum I-clamps, and a thick stainless-steel skin. The magnet was previously tested at Fermilab with reduced pre-load, and achieved record 14.1 T fields at 4.5 K. Now the magnet was reassembled with full pre-load and cryogenically retested. This paper reports the magnetic measurements results of these tests, including field strength, geometrical harmonics, coil magnetization, and iron saturation characteristics of the demonstrator.

The US Department of Energy (DOE) Office of Science (SC), is funding a large bore "Cable Test Facility Magnet" for testing advanced cables and inserts in high transverse field. This is a joint effort between the Office of High Energy Physics (HEP) and the Office of Fusion Energy Sciences (FES). The background field magnet for this facility is being developed at Lawrence Berkeley National Laboratory (LBNL) while the cryostat and test facility will be located and operated by Fermi National Accelerator Laboratory (FNAL). The Nb3Sn dipole magnet, which will provide the transverse background field, is designed to generate a field of 15 T in a 100 x 150 mm bore at 1.9 K. The conceptual design of a block-type dipole with flared ends and a structure based on key-and-bladder technology will be introduced. The results of the magnetic and mechanical analysis will be presented.

High Field Vertical Magnet Test Facility (HFVMTF) is a joint project between the Office of High Energy Physics (HEP) and the Office of Fusion Energy Sciences (FES). Its construction is currently under way at Fermi National Accelerator Laboratory (Fermilab). As a part of the project a new double bath superfluid helium cryostat has been designed. The cryostat can accommodate magnets with up to 20 tonne weight and 1.3 m diameter. This paper discusses challenges and solutions for cryostat, lambda plate and heat exchanger design, and presents results of performance analysis.

The Deep Underground Neutrino Experiment (DUNE) formed a near detector design group (NDDG) which was tasked with delivering a CDR by the end of 2019. The DUNE Near Detectors will be housed in an underground hall on the Fermilab site. The two main detector systems are a liquid argon detector and a high-pressure gas time projection chamber (HPgTPC). The HPgTPC requires a magnet that generates a 0.5 T solenoidal magnetic field in a large volume of 6 m diameter, and 5 m length. In this paper, we present a superconducting magnet system design. We investigated: an open air core magnet with three coils, and a five-coils system having two active fringe field shielding coils. Coils positions were optimized to obtain the specified field homogeneity in the magnet good field region, while minimizing the Lorentz forces and the superconductor volume. We discuss the magnetic, mechanical, and thermal conceptual designs.

Magnetic measurements are an integral part of the development cycle of accelerator magnets, a part which provides necessary feedback to drive design and manufacturing improvements and corrections. Automation of these measurements allows for reduction of human errors and reproducibility of measurements. Realization of automation via coordination that is separated at the architectural level from the functional code provides flexibility in defining measurement procedures and substantial extensibility. The described Single Stretched Wire (SSW) system is an implementation of such a solution with the use of a component-based framework designed to build a family of measurement systems.

Fermilab, in collaboration with CERN, has developed a double-aperture 11-T Nb 3 Sn dipole suitable for the high-luminosity LHC upgrade. During 2012-2014, a 2-m-long single-aperture dipole demonstrator and three 1-m-long single-aperture dipole models were fabricated by FNAL and tested at its Vertical Magnet Test Facility. Collared coils from two of the 1-m-long models were then used to assemble the first double-aperture dipole demonstrator. This magnet had extensive testing in 2015-2016, including quench performance, quench protection, and field quality studies. This paper reports the results of measurements of dynamic effects in the single-aperture and double-aperture 11-T Nb 3 Sn dipoles and compares them with similar measurements in previous NbTi magnets.

The U.S. LHC Accelerator Research Program (LARP) and CERN combined their efforts in developing Nb3Sn magnets for the high-luminosity LHC upgrade. The ultimate goal of this collaboration is to fabricate large aperture Nb3Sn quadrupoles for the LHC interaction regions. These magnets will replace the present 70-mm-aperture NbTi quadrupole triplets for expected increase of the LHC peak luminosity up to 5 × 1034 cm -2s-1 or more. Over the past decade, LARP successfully fabricated and tested short and long models of 90 and 120-mm-aperture Nb3Sn quadrupoles. Recently, the first short model of 150-mm-diameter quadrupole MQXFS was built with coils fabricated both by LARP and CERN. The magnet performance was tested at Fermilab's vertical magnet test facility. This paper reports the test results, including the quench training at 1.9 K, ramp rate and temperature dependence, as well as protection heater studies.

A 2-m-long single-aperture dipole demonstrator and two 1-m-long single-aperture models based on Nb 3 Sn superconductor have been built and tested at FNAL. The two 1-m-long collared coils were then assembled in a twin-aperture Nb 3 Sn dipole demonstrator compatible with the LHC main dipole and tested in two thermal cycles. This paper summarizes the quench performance of the FNAL twin-aperture Nb 3 Sn 11 T dipole in the temperature range of 1.9-4.5 K. The results of magnetic measurements for one of the two apertures are also presented. Test results are compared to the performance of coils in a single-aperture configuration. A summary of quench propagation studies in both apertures is given.

The development of Nb3Sn quadrupole magnets for the High-Luminosity LHC upgrade is a joint venture between the US LHC Accelerator Research Program (LARP)* and CERN with the goal of fabricating large aperture quadrupoles for the LHC interaction regions (IR). The inner triplet (low-β) NbTi quadrupoles in the IR will be replaced by the stronger Nb3Sn magnets boosting the LHC program of having 10-fold increase in integrated luminosity after the foreseen upgrades. Previously, LARP conducted successful tests of short and long models with up to 120 mm aperture. The first short 150 mm aperture quadrupole model MQXFS1 was assembled with coils fabricated by both CERN and LARP. The magnet demonstrated a strong performance at Fermilab's vertical magnet test facility reaching the LHC operating limits. This paper reports the latest results from MQXFS1 tests with changed prestress levels. The overall magnet performance, including quench training and memory, ramp rate, and temperature dependence, is also summarized.

Top quark physics is one of the most important successes of the concluding Tevatron program. In this paper, a summary of the most recent measurements of top quark properties, including the mass and its 2011 average, will be presented. Some common techniques and discussion of major systematic uncertainties for top measurements will also be presented.

This Letter describes the current most precise measurement of the W boson pair production cross section and most sensitive test of anomalous WW gamma and WWZ couplings in p (p) over bar collisions at a center-of-mass energy of 1.96 TeV. The WW candidates are reconstructed from decays containing two charged leptons and two neutrinos. Using data collected by the CDF II detector from 3: 6 fb(-1) of integrated luminosity, a total of 654 candidate events are observed with an expected background of 320 +/- 47 events. The measured cross section is sigma(p (p) over bar -> W+W- +X) = 12.1 +/- 0.9(stat)(-1.4)(+1.6)(syst) pb, which is in good agreement with the standard model prediction. The same data sample is used to place constraints on anomalous WW gamma and WWZ couplings.

Fermilab has finished the first phase of Nb3Sn technology scale up by testing 2-m and 4-m long shell-type dipole coils in a 'magnetic mirror' configuration. The 2-m long coil, made of Powder-in-Tube (PIT) Nb3Sn strand, reached its short sample limit at a field level of 10 T. The 4-m long coil, made of advanced Nb3Sn strand based on the Restack Rod Process (RRP) of 108/127 design, has been recently fabricated and tested. Coil test results at 4.5 K and 2.2 K are reported and discussed.

The random part of the integral field harmonics in a series of superconducting magnets has been used in the past to identify the reproducibility of the coil positioning. Using a magnetic model and a Monte-Carlo approach, coil blocks are randomly moved and the amplitude that best fits the magnetic measurements is interpreted as the reproducibility of the coil position. Previous values for r.m.s. coil displacements for Nb-Ti magnets range from 0.05 to 0.01 mm. In this paper, we use this approach to estimate the reproducibility in the coil position for Nb3Sn short models that have been built in the framework of the FNAL core program (HFDA dipoles) and of the LARP program (TQ quadrupoles). Our analysis shows that the Nb3Sn models manufactured in the past years correspond to r.m.s. coil displacements of at least 5 times what is found for the series production of a mature Nb-Ti technology. On the other hand, the variability of the field harmonics along the magnet axis shows that Nb3Sn magnets have already reached values similar to this obtained for Nb-Ti ones.

The latest top quark mass measurements by the CDF and D0 experiments are presented here. The mass has been determined in the dilepton (t{bar t} {yields} e{mu}, ee, {mu}{mu} + jets + E{sub T}) and lepton plus jets (t{bar t} {yields} e or {mu} + jets + E{sub T}) final states. The most accurate single result from lepton plus jets channel is 173.5{sub -3.6}{sup +3.7}(stat. + Jet Energy Scale Systematic) {+-} 1.3(syst.) GeV/c{sup 2}, which is better than the combined CDF and D0 Run I average. A preliminary and unofficial average of the best experimental Run II results gives M{sub top} = 172.7 {+-} 3.5 GeV/c{sup 2}.