Carmichael J R, Polsky Y, An K, Anovitz L M, Bingham P, Dessieux Luc, Ekici K, Frost M, Pemberton S
Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
University of Tennessee Knoxville, Knoxville, Tennessee 37996, USA.
Rev Sci Instrum. 2020 Aug 1;91(8):084502. doi: 10.1063/5.0013433.
Neutron scattering and neutron imaging have emerged as powerful methods for experimentally investigating material deformation and fluid flow in the interior of otherwise inaccessible or opaque structures. This paper describes the design and provides example uses of a pressure cell developed for investigating such behaviors within geological materials. The cell can accommodate cylindrical samples with diameters up to 38.1 mm and lengths up to 154 mm. Ports in the cell and a pressure isolating sleeve around the sample allow the independent application of confining pressure up to 69 MPa and axial pressure up to 34.5 MPa. Two material versions of the cell have been manufactured and used to date. An aluminum version is typically used for temperatures below 40 °C, because of its relative transparency to neutrons, while a titanium version, which is comparatively more neutron attenuating, is used for experiments requiring triaxial pressurization under conditions up to 350 °C. The pressure cells were commissioned at the VULCAN engineering diffractometer at the Oak Ridge National Laboratory (ORNL), Spallation Neutron Source, and have since been used at the ORNL high flux isotope reactor CG1-D imaging beamline, National Institute of Standard and Technology (NIST) BT-2, and NIST NG6 imaging beamlines.
中子散射和中子成像已成为实验研究难以接近或不透明结构内部材料变形和流体流动的有力方法。本文描述了一种为研究地质材料中的此类行为而开发的压力室的设计，并提供了其应用示例。该压力室可容纳直径达38.1毫米、长度达154毫米的圆柱形样品。压力室中的端口以及样品周围的压力隔离套筒允许独立施加高达69兆帕的围压和高达34.5兆帕的轴向压力。迄今为止，已制造并使用了两种材料版本的压力室。铝制版本通常用于温度低于40°C的情况，因为它对中子具有相对透明度，而钛制版本对中子的衰减相对较大，用于在高达350°C的条件下需要三轴加压的实验。这些压力室已在橡树岭国家实验室（ORNL）的VULCAN工程衍射仪、散裂中子源投入使用，此后还在ORNL高通量同位素反应堆CG1-D成像束线、国家标准与技术研究院（NIST）的BT-2以及NIST的NG6成像束线中使用。
