TY - GEN
T1 - Determining the transmission of thin foil filters for soft X-ray free-electron laser radiation
T2 - SPIE Optics + Optoelectronics 2019
AU - Burian, Tomáš
AU - Hájková, Věra
AU - Saksl, Karel
AU - Vozda, Vojtěch
AU - Makhotkin, Igor A.
AU - Louis, Eric
AU - Schreiber, Siegfried
AU - Tiedtke, Kai
AU - Toleikis, Sven
AU - Keitel, Barbara
AU - Plönjes, Elke
AU - Ruiz-Lopez, Maria Isabel
AU - Kuhlmann, M.
AU - Wodzinski, A.
AU - Enkisch, Hartmut
AU - Hermann, Martin
AU - Strobel, Sebastian
AU - Loch, R.A.
AU - Sobierajski, Ryszard
AU - Jacyna, Iwanna
AU - Klinger, Dorota
AU - Jurek, Marek
AU - Pełka, Jerzy B.
AU - de Vries, Gosse
AU - Störmer, Michael
AU - Scholze, Frank
AU - Siewert, Frank
AU - Mey, Tobias
AU - Chalupský, Jaromir
PY - 2019/5/14
Y1 - 2019/5/14
N2 - An accurate transmission measurement of thin foils (usually made of elemental metals and/or semiconductors), which routinely are used as attenuators in soft x-ray beamlines, end-stations and instruments, represents a long standing problem over the wide experimentation field with photon beams, see for example [1-4]. Such foils are also frequently utilized for blocking long wavelength emission, i.e., UV-Vis-IR radiation, from plasma and high order harmonic sources, whilst soft x-rays emitted from the source pass through the foil with only a slight attenuation. Despite the enormous amount of data available in the literature, e.g., Henke’s tables [5], measurements made on real foils often provide surprising results. In this study, a procedure based on the ablation imprints method is utilized for determination of soft x-ray filter transmission, namely the f-scan technique [6,7]. This technique combines the GMD (Gas Monitor Detector) pulse energy measurement and attenuation of the beam by foils (made of different metallic/semiconducting elements of varying thickness) with areas of ablation imprints created on a suitable target, e.g. PMMA – Poly(methyl methacrylate). The results show only a partial overlap with transmission values found in Henke’s tables. Nevertheless, a good agreement with transmission values determined by conventional radiometry techniques at synchrotron radiation beamlines has been found. Such a difference between the experimentally obtained values and transmissions calculated for a pure element is usually explained by spontaneous formation of oxidized layers on the filter surface and in the near-surface layer and their possible alteration by intense FEL radiation. The first results obtained with Al, Nb, Zr and Si filters at FLASH/FLASH2 (Free-electron LASer in Hamburg tuned to 13.5 nm) facilities will be shown and discussed in this presentation.
AB - An accurate transmission measurement of thin foils (usually made of elemental metals and/or semiconductors), which routinely are used as attenuators in soft x-ray beamlines, end-stations and instruments, represents a long standing problem over the wide experimentation field with photon beams, see for example [1-4]. Such foils are also frequently utilized for blocking long wavelength emission, i.e., UV-Vis-IR radiation, from plasma and high order harmonic sources, whilst soft x-rays emitted from the source pass through the foil with only a slight attenuation. Despite the enormous amount of data available in the literature, e.g., Henke’s tables [5], measurements made on real foils often provide surprising results. In this study, a procedure based on the ablation imprints method is utilized for determination of soft x-ray filter transmission, namely the f-scan technique [6,7]. This technique combines the GMD (Gas Monitor Detector) pulse energy measurement and attenuation of the beam by foils (made of different metallic/semiconducting elements of varying thickness) with areas of ablation imprints created on a suitable target, e.g. PMMA – Poly(methyl methacrylate). The results show only a partial overlap with transmission values found in Henke’s tables. Nevertheless, a good agreement with transmission values determined by conventional radiometry techniques at synchrotron radiation beamlines has been found. Such a difference between the experimentally obtained values and transmissions calculated for a pure element is usually explained by spontaneous formation of oxidized layers on the filter surface and in the near-surface layer and their possible alteration by intense FEL radiation. The first results obtained with Al, Nb, Zr and Si filters at FLASH/FLASH2 (Free-electron LASer in Hamburg tuned to 13.5 nm) facilities will be shown and discussed in this presentation.
U2 - 10.1117/12.2524718
DO - 10.1117/12.2524718
M3 - Conference contribution
T3 - SPIE conference proceedings
BT - Optics Damage and Materials Processing by EUV/X-ray Radiation VII
Y2 - 1 April 2019 through 3 April 2019
ER -