Operation of a 930-MHz High-Resolution NMR Magnet at TML

Abstract

A 920-MHz high-resolution NMR spectrometer has been operating at the Tsukuba Magnet Laboratory (TML) since April 2002. It has proved its effectiveness by determining the 3-D structures of protein molecules. To accelerate studies in structural biology and solid-state NMR, a second high-field NMR magnet was developed and installed at TML. Although its basic design was the same as that of the first magnet, some improvements were made. For the innermost coil, a 16%Sn-bronze-processed (Nb Ti) 3 Sn conductor was employed. The increase in the critical current density above that of a 15%Sn-bronze-processed (Nb Ti) 3 Sn conductor made it possible to reduce the conductor size from 3.5 mm 1.75 mm in the first magnet to 2.80 mm 1.83 mm in the second. At the same operating current of the first magnet, the second magnet is expected to operate at 930 MHz. The liquid helium reservoir and the superfluid helium cooler, which were separated in the first system, were united in the same chamber in the new magnet. The latter magnet was energized up to 21.9 T without quenching in March 2004 and has operated in a persistent-mode at that field. It will be utilized mainly for solid-state NMR measurements.Index Terms-High magnetic field, NMR magnet, nuclear magnetic resonance, superconducting magnet.

Properties of a HTS magnet consisting of pancake windings by using the E-J method

“…Cross-section of the HTS tape is divided into 10 elements. Considering the cross-section of the HTS tape is 4.4×0.285 mm 2 , cross-section of an element is 0.44×0.285 mm 2 . In one pancake winding (Fig.…”

“…A number of superconducting machines are being developed, such as, SMES (Superconducting Magnetic Energy Storage), NMR (Nuclear Magnetic Resonance), MRI (Magnetic Resonance Image) and magnetic separator [1][2][3]. Superconducting magnets are used for most of the superconducting machines.…”

Drift Compensation of 600 MHz NMR Magnet

“…The brass wire was wound for structural protection on the outer coil, and finally, this unit was treated with the vacuum impregnation. When the magnet was being operated in the persistent mode, the equation of the coil voltage was described as (1) The main coil involves a slight resistance . The secondary coil (self inductance ) is connected in series to the main coil (self inductance ) and coupled inductively with the primary coil (mutual inductance ).…”

“…T HE Tsukuba Magnet Laboratory (TML) of the National Institute for Materials Science developed 920 MHz (21.6 T) and 930 MHz (21.8 T) NMR magnets using and NbTi wires [1]. High temperature superconductors (HTS) will be necessary to achieve an NMR magnet over 1 GHz (23.5 T).…”

Development of a Superconducting Joint for High Field NMR

“…A HIGH-SENSITIVITY and high-resolution NMR magnet, such as a 930-MHz NMR [1], is constructed using multiple and superconducting magnets. Each magnet is joined in a series by a superconducting joint between the conductor and the conductor (or the NbTi conductor) and is usually operated in the persistent mode.…”