Abstract
Pinhole imagers are common x-ray diagnostics in high energy density physics experiments, where temperatures exceeding $ {10^7}\,{\rm K} $ are reached in the laboratory. In such extreme conditions, self-emitted black-body x-ray radiation is the main drive for physical phenomena (energy transport, shock waves). In order to avoid damages to the detector, high-pass filters are commonly used. The passed photons are $ {\sim} 10 $ times more energetic than the common photon (maximum of the Planckian) and may fail to show the main drive in the experiment. Here we propose a neutral attenuation pinhole (NAP)—a novel, to the best of our knowledge, pinhole design that provides uniform x-ray attenuation over wavelength while keeping the optimal pinhole diameter. Semi-random distribution of thousands of sub-holes, all located within optimal diameter, results in essential large attenuation while keeping image resolution. Simulations and experimental results of the NAP spatial resolution are similar to a regular pinhole. By using a thick enough substrate, the attenuation is uniform over a wide spectrum. A NAP consisting of a 1 µm thick Au substrate allows constant 1:100 attenuation up to 1.5 keV, while a 3 µm thick substrate can be used up to 5 keV.
© 2020 Optical Society of America
Full Article | PDF ArticleMore Like This
V. Bouffetier, L. Ceurvorst, M. P. Valdivia, F. Dorchies, S. Hulin, T. Goudal, D. Stutman, and A. Casner
Appl. Opt. 59(27) 8380-8387 (2020)
Jonathan Workman, James R. Fincke, George A. Kyrala, and Tim Pierce
Appl. Opt. 44(6) 859-865 (2005)
Q. Yang, W. K. Fullagar, G. R. Myers, S. J. Latham, T. Varslot, A. P. Sheppard, and A. M. Kingston
Appl. Opt. 59(29) 9126-9136 (2020)