SBIR Phase II: Portable Superconducting Verticle Gravity Gradiometer

这个小型企业创新研究二期项目继续开发高灵敏度便携式垂直重力梯度仪。这是基于使用两个GWR超导重力传感器（SGS），它们的敏感轴共线性安装，并配置在差分信号模式。SGS使用一个直径为1/2英寸的铌球悬浮在超导线圈产生的磁场中。本研究的目的是在运输和现场测量过程中对仪器进行冲击硬化。技术方法使用机械约束和夹具来固定球体。研究包括：小结构和特定材料的工程，以尽量减少机械蠕变，疲劳和滞后；并建议用铌化合物代替铌球，以增加球表面磁通量的钉住力。地下目标的远程探测和表征在环境、地质、采矿、工程、执法和战略武器条约应用中具有重要意义。利用重力梯度来确定地下密度比现在的重力技术要优越得多，因为现在的重力技术既耗时又昂贵。拟议的重力梯度仪将使测量更迅速，不需要精确的高程测量来解释，并将提供更清晰的地下密度特征分辨率。便携式重力梯度仪将有许多工程、环境和军事应用。例如：监测从废物储存区或地下储罐泄漏到土壤中的液体；定位废弃矿井、天然空洞、隧道或地下掩体；监测火山等自然地质灾害；以及石油、天然气、地下水或地热的储层监测。

9529827 Warburton This Small Business Innovation Research Phase II project continues development of a highly sensitive and portable vertical gravity gradiometer. This is based on using two GWR Superconducting Gravity Sensors (SGS) mounted with their sensitive axes co-linear and configured in a differencing signal mode. The SGS uses a 1/2" diameter niobium sphere levitated in a magnetic field produced by superconducting coils. The goal of this research is to shock harden the instruments during transport and field measurements. The technical approach uses a mechanical constraint and a clamp to immobilize the sphere. Investigation includes: the engineering of small structures and specific materials to minimize mechanical creep, fatigue and hysteresis; and propose replacing the Nb sphere with Nb compounds to increase pinning forces of magnetic flux in the sphere's surface. Remote detection an characterization of underground targets is of great importance in environmental, geologic, mining, engineering, law enforcement, and strategic arms treaty applications. Using gravity gradients to determine underground density is a far superior technique than present day gravity techniques which are time consuming and expensive. The proposed gravity gradiometer will make measurements more rapidly, will not require a precise elevation survey for interpretation, and will provide sharper resolution of underground density features. The portable gravity gradiometer would have many engineering, environmental and military applications. Examples include: monitoring fluid leakage from waste storage area or underground tanks into the soil; locating abandoned mine workings, natural voids, tunnels or underground bunkers: monitoring natural geologic hazards such as volcanoes; and reservoir monitoring of petroleum, gas, groundwater or geothermal.