Open AccessMeasurement of the absolute number of photons of the hard X‐ray beamline at the Linac Coherent Light Source
Author(s) -
Song Sanghoon,
Alonso-Mori Roberto,
Chollet Matthieu,
Feng Yiping,
Glownia James M.,
Lemke Henrik T.,
Sikorski Marcin,
Zhu Diling,
Moeller Stefan,
Lee Hae Ja,
Hunter Mark S.,
Carini Gabriella,
Tiedtke Kai,
Jastrow Ulf,
Sorokin Andrey,
Richter Mathias,
Owada Shigeki,
Tono Kensuke,
Saito Norio,
Tanaka Takahiro,
Kato Masahiro,
Yabashi Makina,
Robert Aymeric
Publication year - 2019
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/s1600577519000250
Subject(s) - beamline , physics , photon , linear particle accelerator , optics , photon energy , x ray , pulse (music) , synchrotron , atomic physics , detector , beam (structure)
X‐ray free‐electron lasers provide intense pulses of coherent X‐rays with a short pulse duration. These sources are chaotic by nature and therefore, to be used at their full potential, require that every X‐ray pulse is characterized in terms of various relevant properties such as intensity, photon energy, position and timing. Diagnostics are for example installed on an X‐ray beamline to specifically monitor the intensity of individual X‐ray pulses. To date, these can however only provide a single‐shot value of the relative number of photons per shot. Here are reported measurements made in January 2015 of the absolute number of photons in the hard X‐ray regime at LCLS which is typically 3.5 × 10 11 photons shot −1 between 6 and 9.5 keV at the X‐ray Pump–Probe instrument. Moreover, an average transmission of ≈62% of the hard X‐ray beamline over this energy range is measured and the third‐harmonic content of ≈0.47% below 9 keV is characterized.