Absolute radiant power measurement of the X-ray free-electron laser at SACLA
Absolute radiant power measurement of the X-ray free-electron laser at SACLA
复制标题
SACLA X 射线自由电子激光器的绝对辐射功率测量
DOI：
10.1088/1742-6596/425/7/072003
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发表时间：
2013
期刊：
影响因子：
--
通讯作者：
T. Ishikawa
中科院分区：
文献类型：
--
作者：
Takahiro Tanaka;Masahiro Kato;T. Kurosawa;N. Saito;T. Kudo;K. Tono;M. Yabashi;T. Ishikawa
日本硬X射线自由电子激光器（XFEL）SACLA（SPring-8 Angstrom Compact free-electron LAser）于2011年6月达到10 keV光子能量的激光放大。SACLA可以提供波长小于0.1nm的XFEL。由于辐射功率是影响XFEL光束非线性效应的一个基本参数，因此它的绝对测量具有重要意义。在本研究中，使用位于SACLA BL 3的低温辐射计测量了XFEL的绝对辐射功率。还测量了作为硅衰减器厚度的函数的辐射功率以估计高次谐波的贡献。在4.4keV、5.8keV、9.6keV、13.6keV和16.8keV的光子能量下，测量了8 μW ~ 1005 μW的辐射功率。除了4.4 keV的光子能量外，高次谐波的贡献可以忽略不计。4.4keV光子能量中的三次谐波分量约为1%。
The Japanese hard X-ray free-electron laser (XFEL), SACLA (SPring-8 Angstrom Compact free-electron LAser), reached laser amplification at 10 keV photon energy in June 2011. SACLA can provide XFELs with its wavelength of shorter than 0.1 nm. Since the radiant power is a fundamental parameter of the XFEL beam which strongly influences nonlinear effects, its measurement in absolute terms is of significant importance. In the present study, the absolute radiant power of the XFEL was measured using a cryogenic radiometer at the BL3 in SACLA. The radiant power as a function of a silicon attenuator thickness was also measured to estimate the contribution of the higher harmonics. The radiant power in the range between 8 μW and 1005 μW was measured in the photon energies of 4.4 keV, 5.8 keV, 9.6 keV, 13.6 keV and 16.8 keV. The contribution of the higher harmonics is negligible except for the photon energy of 4.4 keV. The third harmonics component in the photon energy of 4.4 keV is about 1 %.