Beam parameters of FLASH beamline BL1 from Hartmann wavefront measurements
| Autor: | Svea Kapitzki, Kai Tiedtke, Bernd Schäfer, Barbara Keitel, Klaus Mann, Pavle Juranić, Elke Plönjes, Peter Großmann, Bernhard Flöter |
|---|---|
| Rok vydání: | 2011 |
| Předmět: |
Physics
Wavefront Nuclear and High Energy Physics business.industry Extreme ultraviolet lithography Free-electron laser Laser 01 natural sciences law.invention 010309 optics Optics Beamline law Extreme ultraviolet 0103 physical sciences 010306 general physics Adaptive optics business Instrumentation Coherence (physics) |
| Zdroj: | Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. 635:S108-S112 |
| ISSN: | 0168-9002 |
| DOI: | 10.1016/j.nima.2010.10.016 |
| Popis: | 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. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect