کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1825681 | 1027367 | 2011 | 5 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Beam parameters of FLASH beamline BL1 from Hartmann wavefront measurements Beam parameters of FLASH beamline BL1 from Hartmann wavefront measurements](/preview/png/1825681.png)
We report on online measurements of beam parameters in the soft X-ray and extreme ultraviolet (EUV) spectral range at the free-electron laser FLASH. A compact, self-supporting Hartmann sensor operating in the wavelength range from 6 to 30 nm was used to determine the wavefront quality of individual free-electron laser (FEL) pulses. Beam characterization and alignment of beamline BL1 was performed with λ13.5 nm/90 accuracy for wavefront rms (wrms). A spot size of 159 μm (second moment) and other beam parameters are computed using a spherical reference wavefront generated by a 5 μm pinhole. Beam parameters are also computed relative to a reference wavefront created by a laser-driven plasma source of low coherence, proving the feasibility of such a calibration and reaching λ13.5 nm/7.5 wrms accuracy. The sensor was used for alignment of the toroidal focusing mirror of beamline BL1, resulting in a reduction of wrms by 25%, and to investigate wavefront distortions induced by thin solid filters.
Journal: Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment - Volume 635, Issue 1, Supplement, 11 April 2011, Pages S108–S112