[10p-M112-1~7] 7.1 X-ray technologies

[10p-M112-7] Fabrication of large scale evaporated Gd absorption grating for neutron phase imaging

〇Tetsuo Samoto¹, Hidekazu Takano¹, Atsushi Momose¹ (1.IMRAM, Tohoku Univ.)

Keywords:X-ray microtomography, gadolinium, diffraction grating

A fabrication method for enlargement of the area of neutron absorption grating was studied using Si microfabrication technology and the oblique evaporation method to get a large field of view of neutron phase imaging. Especially using gadolinium for the neutron absorption grating, it is difficult to make a high aspect ratio structure. A 64-mm square area and 9-μm pitch Gd absorption grating was fabricated through a combination of moving the Si mold and restricting the Gd incident angle during evaporation. This is to upgrade uniformity perpendicular to the grating grooves (X axis). For the uniformity parallel to the grating grooves (Y axis), a long and narrow evaporation boat was employed. We analyzed the density of the obliquely evaporated Gd film using X-ray microtomography. A Gd absorption grating with an effective height of 18 μm in bulk density and a duty cycle of about 0.5 was realized.