Fabrication of PMMA X-ray compound refractive lenses for the Pohang light source and performance tests

Abstract

The majority of studies previously conducted on X-ray compound refractive lenses (CRLs) were related to synchrotron radiation (SR) facilities that had a relatively high photon energy level of several tens of keV. However, the performance of CRLs at an SR source with the main photon flux at a photon energy of 7 - 9 keV, such as that of the Pohang Light Source (PLS), is still not very apparent. In this present study; to find the effective experimental conditions for CRL applications at the PLS, we focused the SR beam by using a CRL fabricated with poly methyl methacrylate (PMMA) under a photon energy of 8 keV. Various CRLs with different configurations were fabricated using the LIGA (Lithographie, Galvanoformung, Abformtechnik) process, and the focused beam size was measured at the PLS by using two different experimental methods. The size of the measured focused beam was 7.2 mu m at a focal length of 298 mm. The CRLs developed in this study have a high potential and could eventually be used in real SR experiments at the PLS.