Lightweight Asymmetry and Magnetism Probe project (LAMP) was proposed in China to observe the polarized radiation around 250 eV emitted by soft X-ray celestial sources, like puslars, active galactic, black hole binaries, etc. To produce the high efficiency soft X-ray polarizer for LAMP, we are developing Co/C, Cr/C, CoCr/C X-ray multilayers using magnetron sputtering and reactive sputtering with nitrogen. Hard X-ray grazing incidence reflectometry (GIXR) and soft X-ray reflectance measurements were used to study the interface and microstructure of different multilayers. In comparison to the multilayers deposited by normal magnetron sputtering, reactively-sputtered multilayers show higher reflectivity around 250 eV and lower interfacial roughness. As a result, Co/C, Cr/C, CoCr/C multilayers with smaller period can be made with respect to the multilayer fabricated using non-reactive sputtering. The X-ray performance of reactive sputtered Co/C and CoCr/C multilayers can be further improved by optimizing the deposition process.

Date Published: 12 May 2015
PDF: 6 pages
Proc. SPIE 9510, EUV and X-ray Optics: Synergy between Laboratory and Space IV, 95100X (12 May 2015); doi: 10.1117/12.2178633

Published in SPIE Proceedings Vol. 9510:
EUV and X-ray Optics: Synergy between Laboratory and Space IV
René Hudec; Ladislav Pina, Editor(s)