A 1.5-T superconducting solenoid-dipole magnet for a magic-angle spinning field

用于魔角旋转场的 1.5T 超导螺线管偶极磁体

• 批准号: 8239103
• 负责人: Yukikazu Iwasa
• 金额: $ 64.73万
• 依托单位: MASSACHUSETTS INSTITUTE OF TECHNOLOGY
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-09-19 至 2014-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8239103
• 关键词: Adopted; Bathing; Data; Detection; Devices; Diagnosis; Disease; Drug toxicity; Ensure; France; Frequencies; Head; Health; Helium; Housing; Human; Laboratories; Liquid substance; Lung; Magic; Magnetic Resonance Imaging; Magnetic Resonance Spectroscopy; Magnetism; Measures; Mechanics; Methods; Mission; Monitor; Nitrogen; Pacific Northwest; Phase; Predisposition; Public Health; Research; Research Personnel; Rotation; Science; Solid; Source; Staging; System; Temperature; Testing; Therapy Evaluation; Time; Tissues; Work; cold temperature; cryogenics; cryostat; design; disorder prevention; improved; innovation; metabolic abnormality assessment; novel; operation; programs; tool; vector

DESCRIPTION (provided by applicant): Phase 1 of this 2-phase program has two specific aims: 1) successful completion of a magic-angle-field (MAF) magnet of a significant field strength with an NMR-quality field homogeneity for slow MAS (magic-angle-spinning) MRI/NMR; and 2) application and demonstration with the proposed system of an innovative cryogenic system suitable for a superconducting magnet spinning in Phase 1 slowly (~0.1 Hz) and in Phase 2 at 6 Hz. Unlike a conventional NMR or MRI magnet that has a field vector of NMR quality directed only in one axis, an MAF vector may be decomposed into two field vectors, one directed in one axis and the other in the direction normal to the first axis. The best, and perhaps the easiest, way to ensure an NMR-quality field directed at an angle of 54.74o from the magnet axis (also the rotation axis) is to ensure independently an NMR-quality field generated by each of the coils comprising an MAF magnet. This is the crux of our innovative design concept to build a successful superconducting MAF magnet: a combination of an axial z-field solenoid coil and an x-axis field dipole coil, each generating an NMR-quality field of a specific strength. By adjusting each coil's field strength, we will be able to achieve with this Phase 1 magnet both requirements of field strength (here 1.5 T) and angle (54.74o). With this magnet, for the very first time, MAS NMR/MRI sciences will have a superconducting MAF magnet that generates an NMR- quality field of significant strength, e.g., 1.5 T >> 36 gauss (the previous high by the UC Berkeley group), operated in persistent mode. Another notable significance is an innovative cryogenics design applied to this magnet (also to used in Phase 2). Instead of operated in a bath of liquid helium (LHe), the magnet will be immersed in solid nitrogen (SN2). (In phase 2,the magnet will be housed in a cryostat which will rotate at 6 Hz.) This all-solid cold body ameliorates thermo-fluid issues associated with LHe under rotation. Also, the presence of SN2 in the cold body not only ensures a more uniform temperature throughout the windings but also provides a large thermal mass, enabling the magnet to maintain its operating field over a time period even when the primarily cooling source (LHe in Phase 1) is shut off. In summary, the successful completion of this 2-phase program will open new opportunities in MAS NMR/MRI sciences, which in turn will open new avenues to modern instrumental analysis, ultimately leading to novel non-invasive biomedical tools for analysis, diagnosis, and disease prevention. PUBLIC HEALTH RELEVANCE: Magnetic Resonance Imaging (MRI) together with localized Magnetic Resonance Spectroscopy (MRS) is a non-invasive method for studying metabolic changes associated with diseases, with applications to detection, diagnosis, monitoring the progress of therapy, and evaluation of drug toxicity. The proposed research is relevant to public health since it promises to extend the capabilities of MRI/MRS to tissues with highly inhomogeneous magnetic susceptibility, such as lung. It is relevant to NIH's mission since it leads directly to innovative research strategies with applications which will ultimately enhance and improve human health.

描述（由申请人提供）：这个两阶段计划的第一阶段有两个具体目标：1) 成功完成具有显着场强的魔角场 (MAF) 磁体，并具有 NMR 质量的场均匀性，适用于慢速 MAS （魔角旋转）MRI/NMR； 2）对所提出的创新低温系统进行应用和演示，该系统适用于超导磁体在第一阶段缓慢旋转（约0.1赫兹）和第二阶段以6赫兹旋转。与具有仅沿一个轴指向的NMR质量的场矢量的传统NMR或MRI磁体不同，MAF矢量可分解为两个场矢量，一个沿一个轴指向，另一个沿垂直于第一轴的方向指向。确保 NMR 质量场与磁体轴（也是旋转轴）成 54.74o 角的最佳（也许是最简单）方法是确保由每个线圈独立生成 NMR 质量场，其中每个线圈包括MAF 磁铁。这是我们构建成功的超导 MAF 磁体的创新设计理念的关键：轴向 z 轴磁场螺线管线圈和 x 轴磁场偶极线圈的组合，每个线圈都会产生特定强度的 NMR 质量场。通过调整每个线圈的磁场强度，我们将能够使用该第一相磁铁实现磁场强度（此处为 1.5 T）和角度（54.74o）的要求。有了这种磁体，MAS NMR/MRI 科学将首次拥有超导 MAF 磁体，该磁体可以产生具有显着强度的 NMR 质量场，例如 1.5 T >> 36 高斯（加州大学伯克利分校小组之前的最高强度） ，以持久模式运行。另一个值得注意的意义是应用于该磁体的创新低温设计（也用于第二阶段）。磁体将浸入固态氮 (SN2) 中，而不是在液氦 (LHe) 浴中运行。 （在第 2 阶段，磁铁将被安置在以 6 Hz 旋转的低温恒温器中。）这种全固态冷体改善了与 LHe 旋转相关的热流体问题。此外，冷体中 SN2 的存在不仅确保了整个绕组的温度更加均匀，而且还提供了较大的热质量，使磁体能够在一段时间内保持其工作磁场，即使主要冷却源（LHe 同相） 1) 已关闭。总之，这个两阶段计划的成功完成将为 MAS NMR/MRI 科学开辟新的机遇，这反过来又将为现代仪器分析开辟新途径，最终带来用于分析、诊断和诊断的新型非侵入性生物医学工具。疾病预防。 公共健康相关性：磁共振成像 (MRI) 与局部磁共振波谱 (MRS) 相结合是一种非侵入性方法，用于研究与疾病相关的代谢变化，可应用于检测、诊断、监测治疗进展和药物评估毒性。拟议的研究与公共卫生相关，因为它有望将 MRI/MRS 的功能扩展到磁化率高度不均匀的组织，例如肺。它与 NIH 的使命相关，因为它直接导致创新研究策略的应用，最终将增强和改善人类健康。