Small-angle x-ray scattering station 4C2 BL of pohang accelerator laboratory for advance in Korean polymer science

Abstract

There are two beamlines (BLs), 4C1 and 4C2, at the Pohang Accelerator Laboratory that are dedicated to small angle X-ray scattering (SAXS). The 4C1 BL was constructed in early 2000 and is open to public users, including both domestic and foreign researchers. In 2003, construction of the second SAXS BL, 4C2, was complete and commissioning and user support were started. The 4C2 BL uses the same bending magnet as its light source as the 4C1 BL. The 4C1 BL uses a synthetic double multilayer monochromator, whereas the 4C2 BL uses a Si(111) double crystal monochromator for both small angle and wide angle X-ray scattering. In the 4C2 BL, the collimating mirror is positioned behind the monochromator in order to enhance the beam flux and energy resolution. A toroidal focusing mirror is positioned in front of the monochromator to increase the beam flux and eliminate higher harmonics. The 4C2 BL also contains a digital cooled charge coupled detector, which has a wide dynamic range and good sensitivity to weak scattering, thereby making it suitable for a range of SAXS and wide angle X-ray scattering experiments. The general performance of the 4C2 BL was initially tested using standard samples and further confirmed by the experience of users during three years of operation. In addition, several grazing incidence X-ray scattering measurements were carried out at the 4C2 BL.

Reversible conformation-driven order–order transition of peptide-mimic poly(n-alkyl isocyanate) in thin films via selective solvent-annealing

“…Synchrotron grazing incidence X-ray scattering (GIXS) measurements GIXS measurements were performed at beamline 3C [19][20][21][22][23] of the Pohang Accelerator Laboratory at the Pohang University of Science and Technology.…”

Dynamic mechanical and morphological studies of styrene-co-methacrylate and sulfonated polystyrene ionomers containing aliphatic dicarboxylate salts

“…The small-angle X-ray scattering (SAXS) experiments were conducted at Station 4C1 of the Pohang Light Source synchrotron radiation source (Pohang, Korea). 15 The generated critical beam energy was 5.5 keV (at 2.5 GeV operation modes), and the size of the beam at the sample was smaller than 1 mm 2 . The position-sensitive two-dimensional CCD X-ray detector was used.…”

New characterization methods for block copolymers and their phase behaviors

“…12,13 The GISAXS patterns appear not ring-shaped but as discrete spots, which correspond to the diffraction patterns that the layers of HPL and planes of {121} DG are parallel to the substrate plane but randomly oriented in-plane. 12,13,108 Figure 11(c) shows a cross-sectional TEM image of the HPL structure. PI domains were selectively stained by OsO 4 and appear darker than PS domains.…”