Title: xcalib : a focal spot calibrator for intense X-ray free-electron laser pulses based on the charge state distributions of light atoms

Abstract

Thexcalibtoolkit has been developed to calibrate the beam profile of an X-ray free-electron laser (XFEL) at the focal spot based on the experimental charge state distributions (CSDs) of light atoms. Characterization of the fluence distribution at the focal spot is essential to perform the volume integrations of physical quantities for a quantitative comparison between theoretical and experimental results, especially for fluence-dependent quantities. The use of the CSDs of light atoms is advantageous because CSDs directly reflect experimental conditions at the focal spot, and the properties of light atoms have been well established in both theory and experiment. Theoretical CSDs are obtained usingxatom, a toolkit to calculate atomic electronic structure and to simulate ionization dynamics of atoms exposed to intense XFEL pulses, which involves highly excited multiple core-hole states. Employing a simple function with a few parameters, the spatial profile of an XFEL beam is determined by minimizing the difference between theoretical and experimental results. The optimization procedure employing the reinforcement learning technique can automatize and organize calibration procedures which, before, had been performed manually.xcalibhas high flexibility, simultaneously combining different optimization methods, sets of charge states, and a wide range of parameter space. Hence, in combination withxatom,xcalibserves as a comprehensive toolmore » to calibrate the fluence profile of a tightly focused XFEL beam in the interaction region.« less

Authors:

Toyota, Koudai; Jurek, Zoltan; Son, Sang-Kil ;

• Search OSTI.GOV for author "Son, Sang-Kil"
• Search OSTI.GOV for ORCID "0000-0001-5395-632X"
• Search orcid.org for ORCID "0000-0001-5395-632X"

Fukuzawa, Hironobu; Ueda, Kiyoshi; Berrah, Nora; Rudek, Benedikt; Rolles, Daniel; Rudenko, Artem; Santra, Robin

• Search OSTI.GOV for author "Santra, Robin"
• Search OSTI.GOV for ORCID "0000-0002-1442-9815"
• Search orcid.org for ORCID "0000-0002-1442-9815"

Publication Date:

2019-05-23

Research Org.:

Kansas State Univ., Manhattan, KS (United States); Univ. of Connecticut, Storrs, CT (United States)

Sponsoring Org.:

USDOE Office of Science (SC)

OSTI Identifier:

1610055

DOE Contract Number:  

FG02-86ER13491; SC0012376

Resource Type:

Journal Article

Journal Name:

Journal of Synchrotron Radiation (Online)

Additional Journal Information:

Journal Volume: 26; Journal Issue: 4; Journal ID: ISSN 1600-5775

Publisher:

International Union of Crystallography

Country of Publication:

United States

Language:

English

Subject:

Instruments & Instrumentation; Optics; Physics