January 2015 Archives

At the soft X-ray free-electron laser (XFEL) facility, FLASH, in Hamburg, Germany, all-optical synchronization has finally been achieved. Scientists are reporting that the timing is better than 30 fs rms for 90 fs X-ray photon pulses. As one of the most promising experiments using XFEL is time-resolved analysis based on the pump & probe scheme, it is crucial to synchronize all independent components, including all accelerator modules and all external optical lasers, to better than the delivered free-electron laser pulse duration such as shorter than 100 fs. For more information, see the paper, "Femtosecond all-optical synchronization of an X-ray free-electron laser", S. Schulz et al., Nature Communications, 6, 5895 (2015).

At the European Synchrotron Radiation Facility (ESRF) in Grenoble, France, scientists from Italy, Germany and France have succeeded in 'reading' letters inside a papyrus roll found in the ancient library, discovered in Herculaneum. The experiments were done at the beamline ID17, and the X-ray phase contrast tomography technique was employed. The team was successful in extracting words under several papyrus layers in a fragment, and finally found that they are the complete Greek alphabet. For more information, see the paper, "Revealing letters in rolled Herculaneum papyri by X-ray phase-contrast imaging", V. Mocella et al., Nature Communications, 6, 5895 (2015). An interesting movie has also been uploaded to Youtube, https://www.youtube.com/watch?v=d3aWBgNYOCU