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At least 145 records · Page 8
All sourcesNASA NTRSDOE OSTI
DOE OSTI2025

Magnetic and Mechanical Analysis of Bi-2212 Rutherford Cable in a Cos-Theta Sub-Scale Dipole Coil

The U.S. Magnet Development Program (US-MDP) explores high-field accelerator magnets compatible with operational conditions beyond the limits of Nb$_3$Sn technology. The ongoing R&D High-Temperature Superconductors (HTS) suggests using Bi$_2$Sr$_2$CaCu$_2$O$_{8-x}$ (Bi-2212) as superconducting element. Bi-2212 Rutherford cables maintain a high critical current (I$_C$) when exposed to a large external magnetic field. However, Bi-2212 exhibits an oversensitive stress-strain response when subject to large Lorentz forces. This paper reports on the magnetic and mechanical analysis of the Bi-2212 cosine-theta insert being developed at Fermilab for a hybrid magnet composed of two external layers of Nb$_3$Sn and two internal layers of Bi-2212. We performed a FEM analysis of the insert to estimate the HTS stress state in the coil's strands under magnetic and mechanical loads.

43 PARTICLE ACCELERATORS↗
DOE OSTI2024

Modeling of Bi-2212 strand and Rutherford cable in a dipole coil insert

The U.S. Magnet Development Program (US-MDP) explores high-field accelerator magnets compatible with op- erational conditions beyond the limits of Nb3Sn technology. The ongoing R&D High-Temperature Superconductors (HTS) suggests using Bi2Sr2CaCu2O8−x (Bi-2212) as superconducting element. Bi-2212 Rutherford cables maintain a high critical current (IC ) when exposed to a large external magnetic field. However, Bi-2122 exhibits an oversensitive stress-strain response when subject to large Lorentz forces. This paper reports on the magnetic and mechanical analysis of the Bi-2212 cosine-theta insert being developed at Fermilab for a hybrid magnet composed of 2 external layers of Nb3Sn and 2 internal layers of Bi-2212. We performed a FEM analysis of the insert to estimate the HTS stress state in the coil s strands under magnetic and mechanical loads.

D'Agliano, A.↗
NASA NTRS1993

Toys in Space, 2

In this educational video from the 'Liftoff to Learning' series, astronauts from the STS-54 Mission (Mario Runco, John Casper, Don McMonagle, Susan Helms, and Greg Harbaugh) explain how microgravity and weightlessness in space affects motion by using both mechanical and nonmechanical toys (gravitrons, slinkys, dart boards, magnetic marbles, and others). The gravitational effects on rotation, force, acceleration, magnetism, magnetic fields, center of axis, and velocity are actively demonstrated using these toys through experiments onboard the STS-54 Mission flight as a part of their spaceborne experiment payload. [Resource Guide referenced in the video is not available.]

Herbert, Dexter↗
DOE OSTI2023

Large-Aperture High-Field Nb 3 Sn Quadrupole Magnets for HiLumi

The HL-LHC Inner Triplet quadrupole magnets use Nb 3 Sn superconductor for the first time in a particle accelerator. Coil peak field, forces, and stored energy density are significantly higher than in previous accelerator magnets. The original design addressed all these challenges. Lessons learned in the early phases made the final design and specifications for series magnets more robust.

43 PARTICLE ACCELERATORS↗
DOE OSTI2024

Rapid-cycling HTS magnet for muon acceleration

A very wide range of operational temperatures of the HTS (YBCO) superconductor makes it suitable for the construction of rapid-cycling magnets required for the muon acceleration. The measured [3] very low power loss of the 0.4 T magnet operating at 300 T/s suggested a realistic possibility of the HTS-based accelerator magnet with much higher magnetic field and ramp rate. The magnet core and the HTS cable designs for the 2 T field in the 30 mm beam gap are presented. The simulation of the HTS cable hysteresis power loss for the 1000 T/s ramp rate is discussed in terms of the operational temperatures and required cryogenic power.

43 PARTICLE ACCELERATORS↗
DOE OSTI2022

Rotating-Coil Measurement System for Small-Bore-Diameter Magnet Characterization

Rotating-coil measurement systems are widely used to measure the multipolar fields of particle accelerator magnets. This paper presents a rotating-coil measurement system that aims at providing a complete data set for the characterization of quadrupole magnets with small bore diameters (26 mm). The PCB magnetometer design represents a challenging goal for this type of transducer. It is characterized by an aspect ratio 30% higher than the state of the art, imposed by the reduced dimension of the external radius of the rotating shaft and the necessity of covering the entire magnet effective length (500 mm or higher). The system design required a novel design for the mechanical asset, also considering the innovation represented by the commercial carbon fiber tube, housing the PCB magnetometer. Moreover, the measurement system is based primarily on standard and commercially available components, with simplified control and post-processing software applications. The system and its components are cross-calibrated using a stretched-wire system and another rotating-coil system. The measurement precision is established in a measurement campaign performed on a quadrupole magnet characterized by an inner bore diameter of 45 mm.

42 ENGINEERING↗
DOE OSTI2020

Development and performance of a 2.9 Tesla dipole magnet using high-temperature superconducting CORC® wires

Although the high-temperature superconducting (HTS) REBa 2 Cu 3 O x (REBCO, RE-rare earth elements) material has a strong potential to enable dipole magnetic fields above 20 T in future circular particle colliders, the magnet and conductor technology needs to be developed. As part of an ongoing development to address this need, here we report on our CORC® canted cosθ magnet called C2 with a target dipole field of 3 T in a 65 mm aperture. The magnet was wound with 70 m of 3.8 mm diameter CORC® wire on machined metal mandrels. The wire had 30 commercial REBCO tapes from SuperPower Inc. each 2 mm wide with a 30 µm thick substrate. The magnet generated a peak dipole field of 2.91 T at 6.290 kA, 4.2 K. The magnet could be consistently driven into the flux-flow regime with reproducible voltage rise at an engineering current density between 400-550 A mm -2 , allowing reliable quench detection and magnet protection. The C2 magnet represents another successful step towards the development of high-field accelerator magnet and CORC® conductor technologies. The test results highlighted two development needs: continue improving the performance and flexibility of CORC® wires and develop the capability to identify locations of first onset of flux-flow voltage.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2025

Fabrication and Test of C3a: A Six-Layer Subscale Canted $\cos \theta$ Dipole Magnet Using High-Temperature Superconducting corc Wires

REBCO coated conductors have a strong potential for high-field magnet applications. The REBCO technology, however, is still in its infancy for accelerator magnet applications. As part of the U.S. Magnet Development Program (MDP), we developed a six-layer canted cos θ dipole magnet, C3a, using CORC® wires developed by Advanced Conductor Technologies LLC. All the layers were wound using a semi-automated winding machine. Three layers of the magnet used CORC® wires containing the SuperPower “AP” REBCO tapes and the remaining layers used the wires containing the “HM” tapes. At 77 K, both kinds of CORC® wires showed 5% to 10% degradation, after bending to a minimum bend radius of 30 or 35 mm, with respect to the self-field critical current measured before winding. At 4.2 K, the magnet reached 9.5 kA at a ramp rate of 9 A s -1 and generated a dipole field of 1.4 T. Further, the critical current of one layer degraded by 4% after a current transient up to 10.5 kA ramped in an averaged rate of 175 kA s -1 or 20 T s -1 . We confirmed the HM CORC® wire can carry a higher current than the AP CORC® wire at 4.2 K. The test results of the C3a magnet showed that the fabrication and assembly procedure can be used for the upcoming full-scale C3 magnet.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2024

Deflection of Plasma by High Magnetic Fields at Variable Pressures (Final Report)

The goal of the proposed work is to study the deflection of plasma by high magnetic fields using the high uniform magnetic field of the Magnetized Dusty Plasma Experiment (MDPX) located at the Magnetized Plasma Research Laboratory (MPRL) at Auburn University. The proposal team consists of faculty from the University of Alabama in Huntsville (UAH). One of the motivations for this work is to study the concept of a magnetic nozzle for pulsed fusion propulsion. Fusion propulsion can provide extremely high specific impulse, >30,000 sec, for fuel-efficient and thus mass-efficient trips to other planets. One such fusion propulsion design of interest in this research is the Pulsed Fission-Fusion (PuFF) concept. PuFF uses a Z-pinch device to create a fusion reaction at the back of the spacecraft inside the magnetic nozzle. As the resulting plasma explosion is isotropic, a large portion of the momentum will be directed toward the ship and needs to be redirected to efficiently produce thrust. The magnetic nozzle is thus necessary to redirect or deflect the plasma from an isotropic expansion into the directed thrust. Thus, the pulsed-fusion propulsion nozzle is herein referred to as a deflection magnetic nozzle, as opposed to the more traditional and well-studied accelerating magnetic nozzle. The purpose of this project was thus to study the behavior of a plasma in the MDPX fields to better understand the plasma-field interactions and how it could lead to deflection and a pulsed fusion magnetic nozzle.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
DOE OSTI2025

Integral Field Probe for Mapping of Curved Magnets

The Single Stretched Wire (SSW) method allows highly precise integral field measurements by recording voltage across a tensioned wire mounted to 2-axis linear stages at either end of the magnet aperture. However, traditional SSW probes are not well suited for curved accelerator magnets, which are essential for steering charged particles along arced trajectories in storage rings or beamlines. The tension required to eliminate sag demands a purely straight path, making them incompatible with non-linear magnet geometries. To address this limitation for curved magnets, a modified approach was developed using a segmented, 3D-printed support structure that incorporates a pre-shaped anti-sag curve. Under its own weight and that of the wire bundle, the structure deforms to lie flat while conforming to the curvature of the magnet in the horizontal plane. The optimal geometry of the probe was derived using an iterative process combining FEA simulations in Ansys Mechanical with testing of various carbon fiber-reinforced filaments. The printed and assembled probe was successfully used to measure the SDD-059 magnet at Fermilab, yielding promising results.

Jakopin, Alexander [Northern Illinois U.]↗
DOE OSTI2024

Multispecies Ion Acceleration in 3D Magnetic Reconnection with Hybrid-Kinetic Simulations

Magnetic reconnection drives multispecies particle acceleration broadly in space and astrophysics. Here we perform the first 3D hybrid simulations (fluid electrons, kinetic ions) that contain sufficient scale separation to produce nonthermal heavy-ion acceleration, with fragmented flux ropes critical for accelerating all species. We demonstrate the acceleration of all ion species (up to Fe) into power-law spectra with similar indices, by a common Fermi acceleration mechanism. The upstream ion velocities influence the first Fermi reflection for injection. The subsequent onsets of Fermi acceleration are delayed for ions with lower charge-mass ratios (Q/M), until growing flux ropes magnetize them. This leads to a species-dependent maximum energy/nucleon ∝(Q/M) α . These findings are consistent with in situ observations in reconnection regions, suggesting Fermi acceleration as the dominant multispecies ion acceleration mechanism.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2024

Development and test of a large-aperture Nb3Sn cos-theta dipole coil with stress management

The stress-managed cos-theta (SMCT) coil is a new concept which was proposed and is being developed at Fermilab in the framework of US Magnet Development Program (US-MDP) for high-field and/or large-aperture accelerator magnets based on low-temperature and high-temperature superconductors. A 120-mm aperture two-layer Nb3Sn SMCT dipole coil has been developed at Fermilab to demonstrate and test the SMCT concept including coil design, fabrication technology and performance. The first SMCT demo coil was fabricated and assembled with 60-mm aperture Nb3Sn coil inside a dipole mirror configuration and tested separately and in series with the insert coil. This paper summarizes the design, parameters, and quench performance of the 120-mm aperture SMCT coil in a dipole mirror configuration.

43 PARTICLE ACCELERATORS↗
DOE OSTI2024

Assessment of Training Performance, Degradation and Robustness of Paraffin-Wax Impregnated Nb 3 Sn Demonstrator Under High Magnetic Field

In the context of high-energy physics, the use of Nb 3 Sn superconducting magnets as a cost-effective and reliable technology depends on improvements in the following areas: long development and manufacturing cycles, conductor degradation after thermal cycling, long training, as well as a demonstration in accelerator magnets with a beam aperture of the full potential of modern Nb 3 Sn conductors. In short, performance, robustness, and cost are the three issues to be addressed. The Magnet Development project (MagDev) of the Swiss Accelerator Research and Technology initiative (CHART) at the Paul Scherrer Institute (PSI) aims to contribute to the solutions to each of these issues, re-thinking the manufacturing and design process. Here in our program, every innovation is to be validated by means of a panoply of fast-turnaround tools: from non-powered and powered samples and coils, tested under background field, to low-field subscale magnets and high field short prototypes. This work presents one element in this panoply of R&D vehicles: a stress-managed Nb 3 Sn coil called BigBOX, impregnated with paraffin wax, and tested, through a collaboration with the Magnet Development Program of the United States (US-MDP), in the background field of Brookhaven National Laboratory (BNL)’s common coils dipole DCC17.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2023

Significant reduction in the low-field magnetization of Nb 3 Sn superconducting strands using the internal oxidation APC approach

Nb 3 Sn superconductors are promising for building accelerator magnets for future energy-frontier circular colliders. A critical factor for this application is the low-field persistent-current magnetization because it leads to several critical issues: e.g. low-field instability (including flux jumps), hysteresis loss, and field errors in magnet bores. Suppression of low-field magnetization requires reduction of low-field critical current density (J c ) or effective subelement size (d eff ). However, reduction of deff of state-of-the-art Nb 3 Sn conductors—the restacked-rod-process (RRP ® ) type—below 40–50 μm without a pronounced decrease in high-field J c is difficult. On the other hand, the internal oxidation method which forms artificial pinning centers (APC) in Nb 3 Sn offers an alternative approach to reducing the low-field magnetization. Compared with a conventional Nb 3 Sn conductor whose flux pinning force versus field (F p –B) curve peaks at ~20% of its irreversibility field (B irr ), the F p –B curve peaks of APC conductors shift to higher fields due to the point pinning effect, leading to flattening of the J c –B curves. The goal of this paper is to quantitatively study how much the APC approach can reduce the low-field magnetization. Here we measured the J c –B curves of an RRP ® conductor and two APC conductors (reacted at 700 °C) from zero field to B irr using a high-field vibrating sample magnetometer. Here the results showed that the APC conductors have higher non-Cu J c at high fields (e.g. 32%–41% higher at 16 T) and simultaneously lower non-Cu Jc at low fields (e.g. 28%–34% lower at 1 T) compared with the RRP ® . This effect is due to a competition between their Nb3Sn layer fraction ratios and layer F p ratios. Suppose they reach the same 16 T non-Cu J c , then the 1 T non-Cu J c and magnetization of the APC conductors are only half or even less compared with the RRP ® conductor.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
NASA NTRS1988

Helical magnetohydrodynamic turbulence and the coronal heating problem

Numerical simulations are used to investigate the relaxation of an unconfined, helically turbulent, fully three-dimensional magnetofluid, with conditions similar to those which are thought to result in the heating of the solar corona. In these simulations, the system evolves through a succession of force free states. After a relatively quiescent period of Ohmic decay, a phase of accelerated magnetic energy dissipation occurs. Some magnetic energy is transformed into kinetic energy, and the magnitude of entrophy created is a nontrival fraction of the mean square electric current. Concentrated vorticity structures are seen to play almost as important a role as electric current sheets in the heating process. Coincident with this accelerated dissipation process, a reorganization of the magnetic fields occurs, with transfer of magnetic energy to both shorter and longer wavelength modes than are initially present. The ratio of the magnetic field to the electric current density, alpha does not in general tend to assume a constant value in the force free regions during the evolution of the magnetofluid.

Dahlburg, R. B.↗
DOE OSTI2025

The Low-Beta Quadrupoles for the High-Luminosity Large Hadron Collider: enabling higher luminosity by using Nb_3Sn conductor

The large-aperture, high-gradient Low Beta Quadrupoles for the High Luminosity Large Hadron Collider at CERN are the cornerstones of this collider. They are first-of-the-kind accelerator magnets bringing Nb_3Sn conductor to High Energy Physics colliders. In the US they are being fabricated and tested by the HL-LHC Accelerator Upgrade Project (AUP), and in Europe by CERN. The design was developed by AUP and CERN in close collaboration. The Q1/Q3 cryo-assemblies contain two 4.2 m long magnets (MQXFA) fabricated and by AUP. They are tested vertically before use in a cry-assembly. In this paper we are going to present the main features of the MQXFA design, results of vertical tests, and main lessons learned. We will also discuss lessons learned for future use of Nb_3Sn magnets in HEP colliders.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2023

Comparison of Multi-Scale Nonlinear and Conventional Linear Methods for Stress Analysis of Nb 3 Sn Superconducting Magnets

Here this is an extension of the work on a multi-scale nonlinear procedure that demonstrated how to conduct nonlinear stress analysis of Nb 3 Sn superconducting accelerator magnets. The nonlinear procedure uses measured stress-strain curves of annealed copper, Nb 3 Sn strands and coil samples as inputs, which reduces the number of assumptions made for material properties—key uncertainties of any engineering analysis. The results from nonlinear analysis, semi-nonlinear analysis, and linear analysis of the same QFFB2 Nb 3 Sn quadrupole magnet under the same temperature and loads, were compared and discussed. The comparison illustrates that nonlinear stress analysis is significantly more accurate than other methods. As the superconducting coil block is a complex, composite material, it would be inadequate to assume the whole coil block to be linear, either isotropic or orthotropic. It is imperative to conduct nonlinear analysis by simulating the superconducting coil to the level of detail of the individual cables and individual strands. The nonlinear stress analysis procedure can be used to simulate not only Nb 3 Sn magnets, but also NbTi and HTS magnets.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2020

Generation of focusing ion beams by magnetized electron sheath acceleration

Abstract We present the first 3D fully kinetic simulations of laser driven sheath-based ion acceleration with a kilotesla-level applied magnetic field. The application of a strong magnetic field significantly and beneficially alters sheath based ion acceleration and creates two distinct stages in the acceleration process associated with the time-evolving magnetization of the hot electron sheath. The first stage delivers dramatically enhanced acceleration, and the second reverses the typical outward-directed topology of the sheath electric field into a focusing configuration. The net result is a focusing, magnetic field-directed ion source of multiple species with strongly enhanced energy and number. The predicted improvements in ion source characteristics are desirable for applications and suggest a route to experimentally confirm magnetization-related effects in the high energy density regime. We additionally perform a comparison between 2D and 3D simulation geometry, on which basis we predict the feasibility of observing magnetic field effects under experimentally relevant conditions.

42 ENGINEERING↗