A 1.15 GHz nuclear magnetic resonance (NMR) spectrometer magnet has been under study at the Institute of Electrical Engineering of the Chinese Academy of Sciences. This NMR magnet requires spatial field homogeneity to reach 4 per million (ppm) in a sphere with a diameter of 40 millimeters. To achieve such a high magnetic field quality, each double pancake was wound with Bi-2223 tapes to reduce...
We present the updated REBCO insert coil technologies applied to the 835-MHz REBCO insert (H835) for the MIT 1.3-GHz NMR magnet (1.3G). As a replacement for the previous 800-MHz REBCO insert that was damaged when it quenched during operation in 2018, we are constructing the 19.6-T H835 based on our new single-coil formation design with a stacked of 40 stainless-steel-co-wound no-insulation...
No-insulation HTS magnets with high thermal stability and high current density have great advantages in the fabrication of ultra-high field NMR magnets. However, the turns of the double pancake coil of NMR magnet made by no-insulation technology are usually inconsistent with the theoretical value to keep the outer diameter of the coil consistent in engineering application, which affects the...
A desktop 300MHz nuclear magnetic resonance (NMR) superconducting magnet with conduction-cooled cryostat system was developed in Institute of Electrical Engineering, Chinese Academy of Sciences (IEE, CAS). The magnet has a standard 54mm-diameter warm bore with length 600mm, and the 5 Gauss line is actively shielded within the region 650mm (z) ×400mm (r). The operating current is 111.46A with a...
Aiming at the very small-scale NMR magnets, the authors have studied to detect NMR signals for NMR relaxometry using the single-sided magnetic pole which contained the high temperature superconducting (HTS) bulk magnet. The NMR signal relaxation rate depends on the mobility of molecules, including fluctuations and diffusion, in the microscopic environment. This measurement method can acquire...
A ferromagnetic shimming has been applied to improve the field homogeneity of NMR magnets. The study deals with the results of evaluating the magnetic field distribution for a 400 MHz all-REBCO NMR magnet at the 20 mm DSV(diameter sphere volume) with mapping experiments. The mapping path consists of 128 positions that moving along the surface of the cylinder 24 mm in diameter and 30 mm in...
A nuclear magnetic resonance (NMR) magnet system equipped with a persistent current switch (PCS) operates efficiently without Joule loss in persistent current mode (PCM). The superconducting joint technique and a persistent current switch (PCS) are essential to develop the PCM. In this study, we fabricated NbTi superconducting joints and measured the resistance of these joints. Based on the...