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: 8647926
• 负责人: Xuan Peng
• 金额: $ 15.03万
• 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 2015-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8647926
• 关键词: Bathing; Beryllium; Caliber; Clinical; Communities; Copper; Development; Dimensions; Elements; Engineering; Environmental Wind; Equation; Filament; 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; Solutions; Stainless Steel; System; Temperature; Testing; Time; Training; Transition Temperature; Tube; Weight; cost; cost effective; cryostat; density; design; improved; innovation; magnetic field; meter; public health relevance; 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 Tesla全身MRI钻头系统，NBTI超导导线已达到其在4 K处的极限。如果使用NBTI，则需要将氦气的超级冷却至1.8-2.4 K，以实现7-11T Bore MRI和NMR系统。所有这些由西门子，飞利浦和GE出售的7T全身MRI背景磁铁都是由Aligent（以前在Magnex之前在Varian中闻名）制造的。 Aligent最近宣布，他们将不再接受这些7T磁铁的订单，并放置了氦气的成本和可用性。一些MRI制造商由于交付问题和氦短缺而停止接受7T MRI的新订单。医学界希望看到7T MRI成为临床系统。因此，价格需要大幅度下降，从长远来看，唯一真正的解决方案是让传导冷却磁铁以将氦短缺问题从等式中删除。 NB3SN超导导线是这些应用的理想候选者，因为其在较高场（如10-16T）处的电流密度较高。另外，过渡温度（TC）较高 NB3SN与NBTI的9K 17K。当在液态氦气浴中冷却大型NBTI磁铁时，线圈中的温度差异必须小于1K。在7K NB3SN时，仍保留了1/2以上的工程电流密度，以便在大磁铁的孔中设计7-12T磁场，并且提供了2-3K的边缘以实现传导冷却，并消除了对液态氦气浴冷却的需求。这消除了每次需要冷却磁铁时需要4000-6000升氦气的需求（在工厂中训练磁铁，在医院设置磁铁，当磁铁在其7-10年的使用寿命中几次淬火时）。我们的大型传导冷却NB3SN磁铁的特定目的是，Hyper Tech开发了低成本和高性能管NB3SN超导体，这是开放该市场的出色电线候选者。随着性能的提高，它可以从经济上实现传导冷却磁铁并消除氦批冷却。这种新的，超级技术，较低的成本，高性能（JC为2000a/mm2，为4.2k -12t）NB3SN超导电线可以降低与NBTI电线相关的电线成本，以获得7 Tesla全身MRI。它将大大降低磁铁的重量和尺寸。它还将使4-7K范围的传导冷却成为可能。在这个快速轨道I期和II期项目中，我们将证明由Hyper Tech开发的新的低成本NB3SN超导体可用于制造7T TESLA MRI和NMR系统的大型传导冷却50-100厘米的孔线圈。这将使需要高分辨率和快速成像的MRI和NMR应用程序受益。这与NIH的使命是向公众提供具有成本效益的改进医疗保健。