Stability evaluation of a double crystal monochromator using an optical linear encoder

THP52
18 Sept 2025, 16:40
1h
The Loop

The Loop

Lund, Sweden
Poster Presentation Stability Issues Thursday Poster Session

Speaker

Masato Okui (Kohzu Precision Co., Ltd. (Japan), University of Hyogo)

Description

A dedicated jig with an optical linear encoder was developed to evaluate the pitching stability between the first and second crystals of a double crystal monochromator in a standalone configuration. This method does not require synchrotron radiation, enabling direct assessment of the monochromator's intrinsic stability. Unlike beamline-based measurements influenced by upstream optics, this approach isolates the monochromator's performance. Designed and implemented by Kohzu Precision, the system is currently applied to a symmetrical layout monochromator to assess angular stability in mechanically decoupled configurations. The encoder counter supports readout rates up to 12 MHz; however, considering the latch interval of the system, the effective sampling rate is about 5 kHz. Measurements were conducted at approximately 2 kHz. At a Bragg angle of 10 degrees, the angular stability (RMS) in the pitching direction was better than 20 nrad, and a dominant vibration peak was observed near 180 Hz. These results demonstrate the system's effectiveness in characterizing the stability of high-performance monochromator configurations.

Author

Masato Okui (Kohzu Precision Co., Ltd. (Japan), University of Hyogo)

Co-authors

Atsushi Shimoguchi (Kohzu Precision Co., Ltd. (Japan)) Daiki Nagata (Kohzu Precision Co., Ltd. (Japan)) Hironobu Fukuzawa (Photon Science Innovation Center) Hiroyuki Yamane (Photon Science Innovation Center) Junya Yoshida (Tohoku University) Naoki Yato (Kohzu Precision Co., Ltd. (Japan)) Tetsuya Nakamura (Tohoku University, Photon Science Innovation Center) Yuki Ikeya (Photon Science Innovation Center)

Presentation materials

There are no materials yet.