Open AccessDesign of a prototype split‐and‐delay unit for XFEL pulses, and their evaluation by synchrotron radiation X‐rays
Author(s) -
Sakamoto Jun'ya,
Ohwada Kenji,
Ishino Masahiko,
Mizuki Jun'ichiro,
Ando Masami,
Namikawa Kazumichi
Publication year - 2017
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/s1600577516017744
Subject(s) - optics , physics , picosecond , femtosecond , synchrotron radiation , laser
A prototype split‐and‐delay unit (SDU) for X‐ray free‐electron laser (XFEL) pulses is proposed based on the Graeff–Bonse four‐Bragg‐reflection interferometer by installing 12.5° slopes. The SDU can continuously provide a delay time from approximately −20 to 40 ps with a resolution of less than 26 fs. Because the SDU was constructed from a monolithic silicon crystal, alignment is straightforward. The obtained thoroughputs of the SDU reached 0.7% at 7.46 keV and 0.02% at 14.92 keV. The tunability of the delay time using the proposed SDU was demonstrated by finding the interference effects of the split X‐rays, and the time resolution of the proposed SDU was evaluated using the width of the interference pattern recorded on the X‐ray charge‐coupled device camera by changing the energy, i.e. longitudinal coherence length, of the incident X‐rays. It is expected that the proposed SDU will be applicable to XFEL experiments using delay times from tens of femtoseconds to tens of picoseconds, e.g. intensity correlation measurements.