Fabrication of soft x-ray windows based on multilayer graphene films

Soft x-ray windows are critical components for enabling the transmission of x rays from vacuum to the atmosphere. Existing windows face several challenges, including high absorption rates, degradation, complex fabrication processes, and limited transmission efficiency. This paper presents the design of a graphene-based soft x-ray window, leveraging the material’s exceptional optical transparency and impermeability to gases. The window consists primarily of a graphene film deposited on a porous tungsten foil, fabricated using chemical vapor deposition and etching techniques. The study demonstrates that the graphene window exhibits high uniformity, excellent mechanical strength, and robust vacuum sealing properties. The leakage rate of the graphene window increases linearly within the helium gas pressure range of 5–120 kPa, with a maximum leakage rate not exceeding 2 × 10−8 Pa m3 s−1. For soft x rays with energies ranging from 100 to 1000 eV, the graphene window shows an average transmission rate of up to 55%, with the transmission in the self-supporting region reaching as high as 84%, significantly outperforming traditional silicon nitride windows. This novel soft x-ray window has potential applications in fields such as materials characterization, medical diagnostics, and micro- and nanofabrication.