On the thermal stability of multilayer optics for use with high X-ray intensities

Zakharova, Margarita (author), Rek, Zlatko (author), Šarler, Božidar (author), Bajt, Saša (author)

High-intensity X-ray free electron laser (XFEL) beams require optics made of materials with minimal radiation absorption, high diffraction efficiency, and high radiation hardness. Multilayer Laue lenses (MLLs) are diffraction-based X-ray optics that can focus XFEL beams, as already demonstrated with tungsten carbide/silicon carbide (WC/SiC)-based MLLs. However, high atomic number materials such as tungsten strongly absorb X-rays, resulting in high heat loads. Numerical simulations predict much lower heat loads in MLLs consisting of low atomic number Z materials, although such MLLs have narrower rocking curve widths. In this paper, we first screen various multilayer candidates and then focus on Mo2C/SiC multilayer due to its high diffraction efficiency. According to numerical simulations, the maximum temperature in this multilayer should remain below 300°C if the MLL made out of this multilayer is exposed to an XFEL beam of 17.5 keV photon energy, 1 mJ energy per pulse and 10 kHz pulse repetition rate. To understand the thermal stability of the Mo2C/SiC multilayer, we performed a study on the multilayers of three different periods (1.5, 5, and 12 nm) and different Mo2C to SiC ratios. We monitored their periods, crystallinity, and stress as a function of annealing temperature for two different heating rates. The results presented in this paper indicate that Mo2C/SiC-based MLLs are viable for focusing XFEL beams without being damaged under these conditions.

• Language: English
• Keywords: x-ray optics, multilayer Laue lens, thermal stability, numerical simulation
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FS - Faculty of Mechanical Engineering
• Publication status: Published
• Publication version: Version of Record
• Year: 2024
• Number of pages: Str. 1933-1948
• Numbering: Vol. 14, iss. 8
• PID: 20.500.12556/RUL-159255
• UDC: 535:519.62
• ISSN on article: 2159-3930
• DOI: 10.1364/OME.527226
• COBISS.SI-ID: 200647939
• Publication date in RUL: 04.07.2024

Record is a part of a journal

• Title: Optical materials express
• Shortened title: Opt. mater. express
• Publisher: Optical Society of America
• ISSN: 2159-3930
• COBISS.SI-ID: 17733142

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.

Secondary language

• Language: Slovenian
• Keywords: rentgenska optika, večplastna leča Laue, termična stabilnost, numerične simulacije