Characteristics of focused soft X-ray free-electron laser beam determined by ablation of organic molecular solids

J. Chalupský, L. Juha, J. Kuba, J. Cihelka, V. Hájková, S. Koptyaev, J. Krása, A. Velyhan, M. Bergh, C. Caleman, J. Hajdu, R. M. Bionta (+17 others)
2007 Optics Express  
A linear accelerator based source of coherent radiation, FLASH (Free-electron LASer in Hamburg) provides ultra-intense femtosecond radiation pulses at wavelengths from the extreme ultraviolet (XUV; λ<100nm) to the soft X-ray (SXR; λ<30nm) spectral regions. 25-fs pulses of 32-nm FLASH radiation were used to determine the ablation parameters of PMMA -poly (methyl methacrylate). Under these irradiation conditions the attenuation length and ablation threshold were found to be (56.9±7.5) nm and ~2
more » ... .9±7.5) nm and ~2 mJ·cm -2 , respectively. For a second wavelength of 21.7 nm, the PMMA ablation was utilized to image the transverse intensity distribution within the focused beam at µm resolution by a method developed here.
doi:10.1364/oe.15.006036 pmid:19546907 fatcat:fmg5arowvffsjkbyqgeavo4cc4