Conveners
Fri-Mo-Po.04 - Magnets for NMR
- Vijay Soni (GE HealthCare Technology & Innovation)
- Bin He (Siemens (ShenZhen) Magnetic Resonance Ltd.)
In this paper, we present the finalized design, construction, and test results of a cryogen-free, iron-shielded 23.5-T/28-mm room-temperature bore REBCO magnet, developed for use in benchtop 1-GHz microcoil NMR spectroscopy. This benchtop magnet is composed entirely of REBCO conductors and operates at ~10 K in a conduction-cooled cryostat, featuring an external iron cylinder outside the vacuum...
Accurate magnetic field correction is essential in MR applications to achieve high field homogeneity and reduce manufacturing complexities. This study proposes an adaptive shim design method that leverages recursive linear programming for efficient optimization of shim configurations. Conventional nonlinear optimization approaches, such as Sequential Quadratic Programming (SQP), often result...
The Halbach magnets are assembled from multiple magnetic pole modules according to certain rules. Due to its small size, it can be made into desktop magnetic resonance equipment and have wide applications in food composition testing and chemical composition detection areas. Because of the use of permanent magnetic materials and assembly processes, the magnetic field uniformity of Halbach is...
Building upon the successful development of 26.86 T @ 30 mm and 16.6 T @ 100 mm fully REBCO high temperature superconducting (HTS) magnets, we have initiated the research and development of an 800 MHz NMR magnet with a 54 mm room-temperature bore. High-field HTS magnets face significant challenges during operation, such as pronounced screening current effects, which lead to poor magnetic field...
Extremely high field NMR magnets have received much attention by improved resolution and higher sensitivity. However, one of the main reasons limiting its development is the magnetic field inhomogeneities generated by high-temperature superconducting (HTS) magnets cannot be compensated by conventional superconducting and room temperature shim coils. The design, fabrication, and testing results...
We have been conducting the basic design, fabrication, and testing of a joint-less high-temperature superconducting (HTS) magnet operating in persistent current mode using second-generation HTS conductors. The joint-less winding method is typically used to produce double pancake coils, but for magnet applications, multiple coils must be stacked. However, the inherent characteristics of the...
The extremely high magnetic fields offer significant advantages in improving imaging quality and analyzing the fine structures of materials. However, these benefits critically depend on achieving high levels of B0 magnetic field homogeneity. This necessitates the development of advanced shimming technologies, which can be effectively realized using superconducting shim coils. This paper...
A 9.4 T cryogen-free system developed by Cryogenic Limited has been used for the high resolution solid-state magic angle spinning (MAS) and liquid-state NMR experiments. The temporal magnetic field distortion due to the cold head operation was 2 Hz peak-to-peak on the resonance frequency 400 MHz [1]. This distortion occurred at the frequency of 1.7 Hz in our experimental setup.
In...
