Liquid Helium Bath Free, Conduction Cooled Nb3Sn Superconducting 7 Tesla Plus Mag

无液氦浴、传导冷却 Nb3Sn 超导 7 Tesla Plus Mag

• 批准号: 9099811
• 负责人: Xuan Peng
• 金额: $ 50.05万
• 依托单位: HYPER TECH RESEARCH, INC.
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-09-19 至 2018-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9099811
• 关键词: Bathing; Beryllium; Caliber; Clinical; Communities; Copper; Development; Dimensions; Elements; Engineering; Environmental Wind; Equation; Filament; Health; Healthcare; Heating; Helium; Hospitals; Hybrids; Image; Joints; Length; Life Cycle Stages; Liquid substance; Magnetic Resonance Imaging; Magnetism; Manufacturer Name; Marketing; Medical; Mission; Modeling; Particle Accelerators; Performance; Phase; Price; Procedures; Property; Resistance; Resolution; Site; Stainless Steel; System; Temperature; Testing; Time; Training; Transition Temperature; Tube; Weight; cost; cost effective; cryostat; density; design; improved; innovation; magnetic field; meter; research and development; thermal stress

DESCRIPTION (provided by applicant): For 7 tesla full body MRI bore magnet systems, NbTi superconductor wire has reached its limit at 4 K. Above 7T if NbTi is used it requires super cooling of helium to 1.8-2.4 K to achieve 7-11T bore MRI and NMR systems. All these 7T full body MRI background magnets sold by Siemens, Philips, and GE have been manufactured by Aligent (formerly known at Varian before that Magnex). Aligent recently announced that they will no longer accept orders for these 7T magnets and sited costs and availability of helium. Some MRI manufacturers have stopped accepting new order for 7T MRIs because of delivery issues and helium shortages. The medical community would like to see 7T MRI's become a clinical system. Hence, the price needs to come down dramatically and in the long run the only real solution is to have conduction cooled magnets to take the helium shortage issue out of the equation. Nb3Sn superconductor wire is the ideal candidate for these applications due to its higher current density at higher field like 10-16T. Plus, the transition temperature (Tc) is higher 17K for Nb3Sn vs. 9K for NbTi. When a large NbTi magnet is cooled in a liquid helium bath, the temperature differential in the coil needs to be less than 1K. At 7K Nb3Sn still retains over 1/2 its engineering current density to enable the design of 7-12T magnetic fields in the bore of large magnets, and it provides the 2-3K margin to enable conduction cooling and can eliminate the need for liquid helium bath cooling. This eliminates the need for 4000-6000 liters of helium every time the magnet needs to be cooled down (training the magnet in the factory, setting up the magnet at the hospital, and when the magnet quenches several times over its useful life cycle of 7-10 years). What enables our specific aim of large conduction cooled Nb3Sn magnets for medical applications is that Hyper Tech has developed a low cost and high performance tube type Nb3Sn superconductor which is an excellent wire candidate to open up this market. With the increase in performance it can economically enable conduction cooled magnets and eliminate the helium batch cooling. This new, Hyper Tech, lower cost, high performance (Jc of 2000A/mm2 at 4.2K-12T) Nb3Sn superconductor wire could cut the wire cost -compared to NbTi wire for a 7 Tesla full body MRI. It would dramatically decrease the magnet weight and size. It will also make the conduction cooling possible for the 4-7K range. During this Fast Track Phase I and Phase II project we will demonstrate that a new low cost Nb3Sn superconductor developed by Hyper Tech can be used to fabricate large conduction cooled 50-100 cm bore coils for 7T tesla MRI and NMR systems. This will benefit the public for MRI and NMR applications that require high resolution and rapid imaging. This matches NIH's mission of delivering cost effective improved health care to the public.

描述（由申请人提供）：对于7特斯拉全身MRI孔磁体系统，NbTi超导导线在4 K时达到极限。在7 T以上，如果使用NbTi，则需要将氦过冷至1.8- 2.4K以实现7- 11 T孔MRI和NMR系统。Siemens、Philips和GE销售的所有这些7 T全身MRI背景磁体均由Aligent（在Magnet之前在Varian称为）制造。Aligent最近宣布，他们将不再接受这些7 T磁体的订单，并确定了氦气的成本和可用性。由于交付问题和氦气短缺，一些MRI制造商已经停止接受7 T MRI的新订单。医学界希望看到7 T MRI成为临床系统。因此，价格需要大幅下降，从长远来看，唯一真实的解决方案是传导冷却磁体，以解决氦气短缺问题。Nb_3Sn超导线材由于其在10- 16 T的高磁场下具有较高的电流密度而成为这些应用的理想候选者。此外，转变温度（Tc）更高 Nb 3Sn为17 K，NbTi为9 K。当大型NbTi磁体在液氦浴中冷却时，线圈中的温差需要小于1 K。在7 K下，Nb 3Sn仍然保持超过1/2的工程电流密度，以使大型磁体的孔中能够设计7- 1/2 T的磁场，并且它提供了2- 3 K的裕度，以使传导冷却成为可能，并且可以消除对液氦浴冷却的需要。这消除了每次磁体需要冷却时需要4000-6000升氦气的需要（在工厂培训磁体，在医院设置磁体，以及磁体在其7-10年的使用寿命周期内淬火多次）。是什么使我们的医疗应用的大型传导冷却Nb 3Sn磁体的具体目标是，Hyper Tech已经开发出一种低成本和高性能的管式Nb 3Sn超导体，这是一个很好的候选线打开这个市场。随着性能的提高，它可以经济地实现传导冷却磁体，并消除氦气批量冷却。这种新的、Hyper Tech、低成本、高性能（在4.2K-12 T下的Jc为2000 A/mm 2）Nb 3Sn超导导线可以降低导线成本-与用于7特斯拉全身MRI的NbTi导线相比。这将大大减少磁铁的重量和尺寸。它还将使传导冷却在4- 7 K范围内成为可能。在这个快速通道第一阶段和第二阶段项目中，我们将证明Hyper Tech开发的新型低成本Nb 3Sn超导体可用于制造7 T特斯拉MRI和NMR系统的大型传导冷却50-100 cm内径线圈。这将有利于公众的MRI和NMR应用，需要高分辨率和快速成像。这符合NIH的使命，即为公众提供成本效益高的医疗保健。