Determination of x-ray free electron laser power using a room-temperature calorimeter
At a Glance
Section titled āAt a Glanceā| Metadata | Details |
|---|---|
| Publication Date | 2016-01-15 |
| Journal | Metrologia |
| Authors | Takahiro Tanaka, Masahiro Kato, Norio SaitƓ, Kensuke Tono, Makina Yabashi |
| Institutions | SPring-8, National Institute of Advanced Industrial Science and Technology |
| Citations | 4 |
Abstract
Section titled āAbstractāA room-temperature calorimeter was developed for the absolute laser power measurement of x-ray free electron lasers (XFELs) at the SPring-8 Angstrom Compact free electron LAser facility in Japan. In the photon energy range from 4.5 keV to 15 keV, this calorimeter was demonstrated to accurately measure laser powers of XFEL up to 6.9 mW. In addition, an online beam monitor, based on the detection of backscattered x-rays from a thin diamond film, was calibrated with the room-temperature calorimeter. The calibration results were compared with those obtained previously with a cryogenic radiometer (the primary standard detector for synchrotron radiations in Japan). The calibration results obtained with the two detectors agreed well within 1.2%, which is well below their combined relative standard uncertainty. Moreover, the spectral responsivity of the beam monitor was found to show a strong photon energy dependence owing to Debye-Scherrer diffraction patterns from the thin-film.