guest ::
| Home > Publications database > Thermal stability of multilayers for use with high X-ray intensities |
| Home > Publications database > Thermal stability of multilayers for use with high X-ray intensities |
| Abstract | PUBDB-2024-01460 |
; ; ;
2024
Abstract: Focusing X-ray free electron laser (XFEL) beams to achieve the necessary power densities for applications such as single-particle imaging or nonlinear physics demands optics with high radiation hardness and minimal absorption. Further development of XFELs towards hard X-ray photon energies challenges existing nano-focusing optics able to withstand XFEL beams [1-2].We are actively developing multilayer Laue lenses (MLLs), which are diffraction-based X-ray optics capable of focusing hard X-rays to nanometer spot sizes [3]. However, current MLLs predominantly utilize high contrast multilayer pairs, which means one of the materials consists of a high atomic number material such as tungsten, tungsten silicide or tungsten carbide. Numerical simulations indicate that these MLLs face significant heat loads under high incident fluxes and pulse repetition rates [4]. Even though MLLs consisting of WC/SiC, for example, have very high thermal stability [5] and the multilayer itself might survive high heat loads, these can cause detachment of the MLLs from the substrate as observed experimentally under particular conditions [6]. This indicates that not only the MLL materials but also the mounting geometry of MLLs to the substrate has to be considered [4]. However, according to numerical simulations, replacing high atomic number materials with lower atomic number materials should be much more effective in reducing the heat load than changing the mounting geometry.Hence, we explored different material pairs with lower atomic numbers, which could potentially form high quality multilayers and could be used to prepare MLLs to focus XFEL beams. Here, we will present our numerical and experimental investigations into screening various multilayer material pairs in terms of their stress, thermal resilience, and expected efficiency. Annealing studies of the most promising multilayer pair of different periods and material ratios will be shown in more detail. According to our numerical simulations the maximum temperature in MLLs consisting of this multilayer should not exceed 300 ºC when focusing an XFEL beam with an energy of 1 mJ per pulse and a repetition rate of 10 kHz. The study was focused on monitoring different properties of the multilayer structure and their change as a function of annealing temperature. Future experiments will determine if these are good predictors of the thermal stability of MLLs under the XFEL beam.References:[1] David, C., et al., (2011). Sci. Reports, 1, (1-5).[2] Yamada, J., et al., (2024). Nature Photonics, (1–6).[3] Bajt, S., et al., (2018). Light: Science & Applications, 7 (1-9).[4] Rek, Z., et al., (2022). Photonics, 9 (1-18). [5] Prasciolu, M., and Bajt, S., (2018), Appl. Sci., 8 (1-15).[6] Prasciolu, M., et al., (2021). SPIE, International Conference on X-Ray Lasers, 11886 (159–166).
|
The record appears in these collections: |