Fabrication Progress of the Outsert Coils of the Series-Connected Hybrid Magnets

Dixon, I.R.; Adkins, Todd; Ehmler, H.; Marshall, William; Bird, M.D.

doi:10.1109/tasc.2012.2232338

Cited by 11 publications

(7 citation statements)

References 7 publications

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“…A structural analysis for the three cases normal operation, quench and fault of resistive insert coil verified that the conductor stress levels stay well below the limits [16]. The fabrication of the superconducting cable-in-conduit coil and the cold-mass assembly was completed at the National High Magnetic Field Laboratory (NHMFL), Tallahassee, USA at the end of 2013 [17], [18]. Finally the cold mass was transported to Europe for further assembly into the magnet cryostat together with a pair of 20 kA current leads [19].…”

Section: A Series-connected Hybrid Magnetmentioning

confidence: 99%

First Hybrid Magnet for Neutron Scattering at Helmholtz-Zentrum Berlin

Smeibidl

Bird

Ehmler

et al. 2016

IEEE Trans. Appl. Supercond.

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Abstract-Helmholtz-Zentrum Berlin operates two large scale facilities: the research reactor BER 2 and the synchrotron source for soft x-rays BESSY 2. This year HZB's neutron instrument suite around BER 2 has been strengthened by a unique high magnetic field facility for neutron scattering. Its main components are the High Field Magnet (HFM), the most powerful DC magnet for neutron scattering worldwide, and the Extreme Environment Diffractometer (EXED), the dedicated neutron instrument for time-of-flight technique. The hybrid magnet system is projected according to the special geometric constraints of analysing samples by neutron scattering in a high field magnet. Following our past experience only steady state fields are adequate to achieve the goals of the project. In particular inelastic scattering studies would virtually be excluded when using pulsed magnets. The new series-connected hybrid magnet with horizontal field orientation was designed and

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Section: A Series-connected Hybrid Magnetmentioning

confidence: 99%

First Hybrid Magnet for Neutron Scattering at Helmholtz-Zentrum Berlin

Smeibidl

Bird

Ehmler

et al. 2016

IEEE Trans. Appl. Supercond.

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“…Besides being instrumentally challenging, these high rf fields can induce MAS-driven level crossings among the eigenstates of the quadrupolar nuclide, which in turn will periodically result in the loss of the transferred polarization. 19,20 Improvements in superconducting magnet technologies 21,22 have facilitated the solidstate NMR of half-integer quadrupolar nuclei, as the central transition (CT) spectra usually observed in these species are dominated by a second-order quadrupolar interaction that scales the pattern breadth as the inverse of the applied magnetic field. 23 However, field increases may be associated with requirements to cover wider spectral windows due to larger chemical shift dispersions; this may in turn increase the rf strengths needed to implement the HH match.…”

Section: Introductionmentioning

confidence: 99%

Adiabatic sweep cross-polarization magic-angle-spinning NMR of half-integer quadrupolar spins

Kim

Schurko

et al. 2017

Journal of Magnetic Resonance

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The use of frequency-swept radiofrequency (rf) pulses for enhancing signals in the magic-angle spinning (MAS) spectra of half-integer quadrupolar nuclides was explored. The broadband adiabatic inversion cross-polarization magic-angle spinning (BRAIN-CPMAS) method, involving an adiabatic inversion pulse on the S-channel and a simultaneous rectangular spin-lock pulse on the I-channel (H), was applied to I(1/2)→S(3/2) systems. Optimal BRAIN-CPMAS matching conditions were found to involve low rf pulse strengths for both the I- and S-spin channels. At these low and easily attainable rf field strengths, level-crossing events among the energy levels |3/2〉,|1/2〉,|-1/2〉,|-3/2〉 that are known to complicate the CPMAS of quadrupolar nuclei, are mostly avoided. Zero- and double-quantum polarization transfer modes, akin to those we have observed for I(1/2)→S(1/2) polarization transfers, were evidenced by these analyses even in the presence of the quadrupolar interaction. H-Na and H-B BRAIN-CPMAS conditions were experimentally explored on model compounds by optimizing the width of the adiabatic sweep, as well as the rf pulse powers of the H andNa/B channels, for different MAS rates. The experimental data obtained on model compounds containing spin-3/2 nuclides, matched well predictions from numerical simulations and from an average Hamiltonian theory model. Extensions to half-integer spin nuclides with higher spins and potential applications of this BRAIN-CPMAS approach are discussed.

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“…20,[23][24][25] Under moderate field strengths, conventional CP utilizing rectangular 26,27 or ramped 28 pulses fulfills most of the needs for obtaining spectra from common spin-1/2 nuclei like 13 C, 15 N, or 31 P subject to magic-angle-spinning (MAS). [29][30][31][32] However, the advent of new magnet technologies expected to yield platforms operating at fields ≥25 T, 33,34 call for the development of CP methods that cover broader frequency bandwidths under fast MAS rate and reasonable rf power levels. For instance, the ∼250 ppm range characteristic of 13 C chemical shifts will span in excess of 95 kHz at the 36 T magnet currently being built at the National High Magnetic Field Laboratory (NHMFL) in Tallahassee, Florida.…”

Section: Introductionmentioning

confidence: 99%

“…For instance, the ∼250 ppm range characteristic of 13 C chemical shifts will span in excess of 95 kHz at the 36 T magnet currently being built at the National High Magnetic Field Laboratory (NHMFL) in Tallahassee, Florida. 34 This highlights the need to develop efficient, broadband CP techniques suitable for covering ultrawide spectral windows and accommodating high MAS spinning rates also for these spin-1/2 species. The broadbandness of the BRAIN-CP method makes this a natural candidate to be explored.…”

Section: Introductionmentioning

confidence: 99%

Cross-polarization phenomena in the NMR of fast spinning solids subject to adiabatic sweeps

Gan

Schurko

et al. 2015

The Journal of Chemical Physics

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Cross-polarization magic-angle spinning (CPMAS) experiments employing frequency-swept pulses are explored within the context of obtaining broadband signal enhancements for rare spin S = 1/2 nuclei at very high magnetic fields. These experiments employ adiabatic inversion pulses on the S-channel (13 C) to cover a wide frequency offset range, while simultaneously applying conventional spin-locking pulse on the I-channel (1 H). Conditions are explored where the adiabatic frequency sweep width, ∆ν, is changed from selectively irradiating a single magic-angle-spinning (MAS) spinning centerband or sideband, to sweeping over multiple sidebands. A number of new physical features emerge upon assessing the swept-CP method under these conditions, including multiple zero-and double-quantum CP transfers happening in unison with MAS-driven rotary resonance phenomena. These were examined using an average Hamiltonian theory specifically designed to tackle these experiments, with extensive numerical simulations, and with experiments on model compounds. Ultrawide CP profiles spanning frequency ranges of nearly 6 • γB s 1 were predicted and observed utilizing this new approach. Potential extensions and applications of this extremely broadband transfer conditions are briefly discussed.

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Fabrication Progress of the Outsert Coils of the Series-Connected Hybrid Magnets

Cited by 11 publications

References 7 publications

First Hybrid Magnet for Neutron Scattering at Helmholtz-Zentrum Berlin

First Hybrid Magnet for Neutron Scattering at Helmholtz-Zentrum Berlin

Adiabatic sweep cross-polarization magic-angle-spinning NMR of half-integer quadrupolar spins

Cross-polarization phenomena in the NMR of fast spinning solids subject to adiabatic sweeps

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