Open AccessFocusing X‐ray free‐electron laser pulses using Kirkpatrick–Baez mirrors at the NCI hutch of the PAL‐XFEL
Author(s) -
Kim Jangwoo,
Kim Hyo-Yun,
Park Jaehyun,
Kim Sangsoo,
Kim Sunam,
Rah Seungyu,
Lim Jun,
Nam Ki Hyun
Publication year - 2018
Publication title -
journal of synchrotron radiation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.172
H-Index - 99
ISSN - 1600-5775
DOI - 10.1107/s1600577517016186
Subject(s) - beamline , free electron laser , physics , optics , femtosecond , laser , synchrotron , photon energy , linear particle accelerator , beam (structure) , photon
The Pohang Accelerator Laboratory X‐ray Free‐Electron Laser (PAL‐XFEL) is a recently commissioned X‐ray free‐electron laser (XFEL) facility that provides intense ultrashort X‐ray pulses based on the self‐amplified spontaneous emission process. The nano‐crystallography and coherent imaging (NCI) hutch with forward‐scattering geometry is located at the hard X‐ray beamline of the PAL‐XFEL and provides opportunities to perform serial femtosecond crystallography and coherent X‐ray diffraction imaging. To produce intense high‐density XFEL pulses at the interaction positions between the X‐rays and various samples, a microfocusing Kirkpatrick–Baez (KB) mirror system that includes an ultra‐precision manipulator has been developed. In this paper, the design of a KB mirror system that focuses the hard XFEL beam onto a fixed sample point of the NCI hutch, which is positioned along the hard XFEL beamline, is described. The focusing system produces a two‐dimensional focusing beam at approximately 2 µm scale across the 2–11 keV photon energy range. XFEL pulses of 9.7 keV energy were successfully focused onto an area of size 1.94 µm × 2.08 µm FWHM.