Characterization of the LCLS “nanosecond two-bunch” mode for x-ray speckle visibility spectroscopy experiments

Journal Article · Tue May 23 00:00:00 EDT 2017 · Proceedings of SPIE - The International Society for Optical Engineering

DOI:https://doi.org/10.1117/12.2265454· OSTI ID:1393197

Sun, Yanwen ^[1]; Zhu, Diling ^[1]; Song, Sanghoon ^[1]; Decker, Franz -Josef ^[1]; Sutton, Mark ^[2]; Ludwig, Karl ^[3]; Roseker, Wojciech ^[4]; Grubel, Gerhard ^[4]; Hruszkewycz, Stephan ^[5]; Stephenson, G. Brian ^[5]; Fuoss, Paul H. ^[5]; Robert, Aymeric ^[1]

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1. SLAC National Accelerator Lab., Menlo Park, CA (United States)
2. McGill Univ., Montreal, QC (Canada)
3. Boston Univ., Chestnut Hill, MA (United States)
4. Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)
5. Argonne National Lab. (ANL), Lemont, IL (United States)

The generation of two X-ray pulses with tunable nanosecond scale time separations has recently been demonstrated at the Linac Coherent Light Source using an accelerator based technique. This approach offers the opportunity to extend X-ray Photon Correlation Spectroscopy techniques to the yet unexplored regime of nanosecond timescales by means of X-ray Speckle Visibility Spectroscopy. As the two pulses originate from two independent Spontaneous Amplified Stimulated Emission processes, the beam properties fluctuate from pulse pair to pulse pair, but as well between the individual pulses within a pair. However, two-pulse XSVS experiments require the intensity of the individual pulses to be either identical in the ideal case, or with a accurately known intensity ratio. We present the design and performances of a non-destructive intensity diagnostic based on measurement of scattering from a transparent target using a high-speed photo-detector. Individual pulses within a pulse pair with time delays as short as 0.7 ns can be resolved. Moreover, using small angle coherent scattering, we characterize the averaged spatial overlap of the focused pulse pairs. Furthermore, the multi-shot average-speckle contrasts from individual pulses and pulse pairs are compared.

• Research Organization: Argonne National Lab. (ANL), Argonne, IL (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22), Materials Sciences and Engineering Division
• Grant/Contract Number: AC02-06CH11357
• OSTI ID: 1393197
• Journal Information: Proceedings of SPIE - The International Society for Optical Engineering, Vol. 10237; ISSN 0277-786X
• Publisher: SPIE
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY