Fabrication and characterization of the source grating for visibility improvement of neutron phase imaging with gratings
Fabrication and characterization of the source grating for visibility improvement of neutron phase imaging with gratings
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DOI：
10.1063/1.4810014
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发表时间：
2013-06-01
影响因子：
1.6
通讯作者：
Lee, Seung Wook
中科院分区：
文献类型：
--
作者：
Kim, Jongyul;Lee, Kye Hong;Lee, Seung Wook
光栅的制造包括用于高中子吸收线的金属沉积工艺是实现基于光栅的相位成像系统的良好可见性的关键问题。用于中子Talbot-Lau干涉仪的源光栅是钆（Gd）结构的阵列，其通常通过溅射、光刻和化学湿法蚀刻制成。然而，它是非常具有挑战性的，以制造足够的中子衰减约超过20 μ m的Gd结构，使用传统的金属沉积方法，因为缓慢的Gd沉积速率，薄膜应力，高材料成本，等等，在这篇文章中，我们制作的源光栅的中子Talbot-Lau干涉仪通过填充硅结构与Gd 3颗粒。这种新的制造方法使我们能够以一种非常稳定和有效的方式实现比Gd膜结构高得多的GdR填充结构，并且甚至更适合于热多色中子，这比冷中子更难停止。在韩国原子能研究所的HANARO多色热中子光栅干涉仪系统上对新制作的源光栅进行了测试，并将具有新源光栅的中子相位成像系统的亮度和图像与Gd沉积方法制作的源光栅进行了比较。(C)2013 AIP Publishing LLC.
The fabrication of gratings including metal deposition processes for highly neutron absorbing lines is a critical issue to achieve a good visibility of the grating-based phase imaging system. The source grating for a neutron Talbot-Lau interferometer is an array of Gadolinium (Gd) structures that are generally made by sputtering, photo-lithography, and chemical wet etching. However, it is very challenging to fabricate a Gd structure with sufficient neutron attenuation of approximately more than 20 mu m using a conventional metal deposition method because of the slow Gd deposition rate, film stress, high material cost, and so on. In this article, we fabricated the source gratings for neutron Talbot-Lau interferometers by filling the silicon structure with Gadox particles. The new fabrication method allowed us a very stable and efficient way to achieve a much higher Gadox filled structure than a Gd film structure, and is even more suitable for thermal polychromatic neutrons, which are more difficult to stop than cold neutrons. The newly fabricated source gratings were tested at the polychromatic thermal neutron grating interferometer system of HANARO at the Korea Atomic Energy Research Institute, and the visibilities and images from the neutron phase imaging system with the new source gratings were compared with those fabricated by a Gd deposition method. (C) 2013 AIP Publishing LLC.