Plasma synthesized doped boron nanopowder for magnesium diboride superconductors

用于二硼化镁超导体的等离子体合成掺杂硼纳米粉体

• 批准号: 8307792
• 负责人: James V Marzik
• 金额: $ 51.53万
• 依托单位: SPECIALTY MATERIALS, INC.
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-05-15 至 2014-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8307792
• 关键词: Address; Affect; Bathing; Boron; Carbon; Characteristics; Chemicals; Collaborations; Cost Savings; Country; Coupled; Development; Diagnosis; Evaluation; Frequencies; Gases; Goals; Heart; Helium; High temperature of physical object; Hospitals; In Situ; Kilogram; Laboratories; Lead; Length; Liquid substance; Magnetic Resonance Imaging; Marketing; Medical; Metals; Methods; Niobium; Particle Size; Performance; Phase; Plasma; Powder dose form; Price; Process; Property; Public Health; Reaction; Reporting; Research; Resources; Risk; Running; Small Business Innovation Research Grant; Solid; Source; System; Technology; Temperature; Testing; Titania; Titanium; Work; base; commercialization; cost; density; improved; magnesium boride (MgB2); magnetic field; manufacturing process; medical specialties; meter; nanopowder; nanosized; next generation; pressure; programs; risk mitigation; scale up; success; vapor

DESCRIPTION (provided by applicant): The availability of magnetic resonance imaging (MRI) scanners is having a significant impact on public health, and greater availability of these units in the US and throughout the world is desired. A primary factor limiting availability is the existing superconductor magnet technology. Presently, commercial MRI magnets require liquid helium (LHe); however, the world's helium supply is decreasing and the price is increasing. As a result, MRI producers are pushing to develop MRI systems based on LHe-free magnesium diboride (MgB2) superconducting magnets. The goal of this project is to develop doped boron nanopowder made by a plasma synthesis process to be used for producing MgB2. Phase I of this project was highly successful. The plasma synthesis process was scaled from a 10 gram laboratory method to a greater than 200 gram process that can produce the kilometer length wires needed for preliminary evaluation of MRI magnets. Wires made from carbon-doped boron nanopowder had critical current densities, Jc, of greater than 105 A/cm2 out to 8 tesla. These are the world's highest performing MgB2 superconductor wires reported to date. This significant improvement exceeded the goals of the program and makes 1.5 and 3 Tesla MRIs based on MgB2 magnets viable in the near-term (3-5 years). The Phase II specific aims are 1) produce multiple kilogram quantities of doped boron nanopowder and use it to fabricate longer lengths of MgB2 wires; 2) scale up the plasma synthesis process for boron nanopowder by increasing the long-term stability and capacity of the plasma synthesis system; and 3) further develop and scale up a vapor-solid synthesis process to make MgB2 nano-sized powder. Specialty Materials, Inc. will complete the work necessary to develop the plasma synthesis process to produce kilogram-sized batches of boron nanopowder that can be used to fabricate multi-kilometer wires needed for commercial MRI magnets. MgB2 nanopowder development will provide risk mitigation by providing raw material for both in situ and ex situ fabrication of MgB2 wires. This project will be carried out in close collaboration with wire fabricators and MRI end users so that the next generation of MRI scanners based on MgB2 superconducting magnets can be commercialized in a 3-5 year timeframe.

描述（由申请人提供）：磁共振成像（MRI）扫描仪的可用性对公众健康产生重大影响，并且希望这些设备在美国和全世界具有更大的可用性。限制可用性的主要因素是现有的超导磁体技术。目前，商用 MRI 磁体需要液氦 (LHe)；然而，世界氦气供应量正在减少，而价格却在上涨。因此，MRI 生产商正在推动开发基于不含 LHe 的二硼化镁 (MgB2) 超导磁体的 MRI 系统。该项目的目标是开发通过等离子体合成工艺制成的掺杂硼纳米粉末，用于生产 MgB2。 该项目第一阶段非常成功。等离子体合成工艺从 10 克实验室方法扩展到大于 200 克的工艺，可以生产 MRI 磁体初步评估所需的公里长电线。由碳掺杂硼纳米粉末制成的导线的临界电流密度 Jc 在 8 特斯拉时大于 105 A/cm2。这些是迄今为止报道的世界上性能最高的 MgB2 超导线材。这一重大改进超出了该计划的目标，并使基于 MgB2 磁体的 1.5 和 3 特斯拉 MRI 在短期内（3-5 年）可行。 第二阶段的具体目标是 1) 生产数公斤数量的掺杂硼纳米粉末，并用它来制造更长长度的 MgB2 线； 2）通过提高等离子体合成系统的长期稳定性和容量，扩大硼纳米​​粉末的等离子体合成工艺； 3) 进一步开发和扩大气固合成工艺来制造 MgB2 纳米粉末。 Specialty Materials, Inc. 将完成开发等离子体合成工艺所需的工作，以生产公斤级批量的硼纳米粉末，这些硼纳米粉末可用于制造商用 MRI 磁体所需的公里长的电线。 MgB2 纳米粉末的开发将为 MgB2 线的原位和异位制造提供原材料，从而降低风险。该项目将与线材制造商和 MRI 最终用户密切合作，以便基于 MgB2 超导磁体的下一代 MRI 扫描仪可以在 3-5 年内实现商业化。