Thermal Radiation Properties of High-Temperature Superconducting Films

高温超导薄膜的热辐射性能

• 批准号: 9102879
• 负责人: Markus Flik
• 金额: --
• 依托单位: Massachusetts Institute of Technology
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-09-01 至 1995-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9102879&HistoricalAwards=false
• 关键词: Thermal; Radiation; Properties; Temperature; Superconducting

High-Tc superconducting films are very promising as coatings for low-temperature radiation shields, potentially yielding heat leaks an order of magnitude smaller than gold films. However, accurate knowledge of the high-Tc film optical properties is required to evaluate the effectiveness of this use of the films. At present, there are no high-precision experimental data for the infrared reflectance of high-Tc superconducting films at low temperatures. Existing data suffer from limited instrument accuracy and reference mirror errors. There are no engineering methods for the precise prediction of this paramever, particularly in the high- reflectance region. To address this problem reflectance measurements of high-Tc superconducting films are being performed with a precision grating spectrometer using an eightfold reflection technique that does not employ a reference mirror. Two theories of superconductor optical properties, based on BCS theory and valid in the pure limit, are compared to these measurements. Approximate relations for engineering use will be derived. The precision reflectance data collected in this study provide for the first time a quantitative assessment of the feasibility of high-Tc superconducting radiation shields.

高温超导薄膜作为低温辐射屏蔽涂层非常有前景，其产生的热泄漏可能比金薄膜小一个数量级。 然而，需要准确了解高 Tc 薄膜的光学特性来评估这种薄膜用途的有效性。 目前，高温超导薄膜在低温下的红外反射率还没有高精度的实验数据。 现有数据受到仪器精度有限和参考镜误差的影响。 没有工程方法可以精确预测该参数，特别是在高反射率区域。 为了解决这个问题，高 Tc 超导薄膜的反射率测量正在使用精密光栅光谱仪进行，该光谱仪使用不使用参考镜的八倍反射技术。 将基于 BCS 理论并在纯极限下有效的两种超导体光学特性理论与这些测量进行了比较。 将导出工程使用的近似关系。 本研究收集的精确反射率数据首次对高温超导辐射屏蔽的可行性进行了定量评估。