Laboratory for Advanced Photonics (LAP)

An international collaboration consisting of metrology and photon diagnostics groups Germany, the U.S.A., Switzerland, and Japan performed a set of cross-calibration measurements of optical properties on the Bernina branch of the Aramis beamline [1].  The collaboration saw the DESY-developed gas detector, a novel diamond detector from Brookhaven, and a room temperature radiometer from AIST in Japan placed at the Bernina end station and measure the absolute intensity of the FEL light as it passed through the optical elements.  The cross-calibrated measurements used in conjuction with the photon beam intensity-gas (PBIG) monitor at the front end of the Aramis beamline to characterize the performance of the optical components on the Bernina branch and then compare them to the expected theoretical values.  The measurements were performed at photon energies of 6.08 and about 7.22 keV.

The high brilliance of new X-ray sources such as X-ray Free Electron Laser opens the way to non-linear spectroscopies. These techniques can probe ultrafast matter dynamics that would otherwise be inaccessible. One of these techniques, Transient Grating, involves the creation of a transient excitation grating by crossing X-ray beams on the sample. Scientists at PSI have realized a demonstration of such crossing by using an innovative approach well suited for the hard X-ray regime.