Soft X‐ray absorption spectroscopy in the low‐energy region explored using an argon gas window. (27th May 2020)

• Record Type: Journal Article
• Authors: Nagasaka, Masanari
• Is Part Of: Journal of synchrotron radiation. Volume 27:Part 4(2020)
• Page Start: 959
• Page End: 962
• Publication Date: 2020-05-27
• Subjects: soft X‐ray absorption spectroscopy -- low‐energy region -- argon gas window -- atmospheric conditions; Synchrotron radiation -- Periodicals; Free electron lasers -- Periodicals; 539.73505
• DOI: 10.1107/S1600577520005883
• Languages: English
• ISSNs: 0909-0495

Abstract

Abstract : Argon gas windows are shown to be effective for soft X‐ray absorption spectroscopy in the low‐energy region below 200 eV under atmospheric conditions. Abstract : The soft X‐ray region below 200 eV is important for investigating chemical and biological phenomena since it covers K ‐edges of Li and B and L ‐edges of Si, P, S and Cl. Helium gas is generally used as the soft X‐ray transmission window for soft X‐ray absorption spectroscopy (XAS) under atmospheric conditions. However, the helium gas window cannot be applied to XAS in the low‐energy region since transmitted soft X‐rays mostly consist of high‐order X‐rays due to the low transmission of first‐order X‐rays. In this study, the argon gas window is proposed as a new soft X‐ray transmission window in the low‐energy region. High‐order X‐rays are removed by the absorption of the Ar L ‐edge (240 eV), and first‐order X‐rays become the major contribution of transmitted soft X‐rays in the low‐energy region. Under atmospheric argon conditions, the double‐excitation Rydberg series of helium gas (60 eV), Si L ‐edge XAS of an Si3 N4 membrane (100 eV) and S L ‐edge XAS of dimethyl sulfoxide gas (170 eV) are successfully measured, indicating that the argon gas window is effective for soft X‐ray transmission in the low‐energy region from 60 eV to 240 eV.