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Describes the development of an undulator beamline for chemical dynamics experiments conducted at the Advanced Light Source facility in Berkeley, California. Description of the beamline; Characterization of the gas harmonic filter; Measurement of the flux from the white beam and monochromator branchlines; Determination of the off-plane Eagle monochromator resolution.

Describes the results of the measurements of spectral and angular distribution of the U5.0 and U8.0 Advanced Light Source undulators. Theory and measurements for on-axis undulator radiation spectra; Spectra of tapered undulator; Near field effect in the off-axis undulator radiation.

Abstract. High-intensity X-ray pulses from third-generation synchrotron sources make it possible to study the temporal dynamics of rapidly evolving materials. We report a study of rapid and reversible disordering of the structure of an InSb crystal induced by an ultrashort laser pulse. A novel crosscorrelation detection technique is described, which allowed us to observe rapid changes in X-ray diffraction that occur on a time-scale of less than 2 ps. [ABSTRACT FROM AUTHOR]

Abstract: X-ray lasers represent a powerful tool to explore matter under extreme conditions. A rigorous characterization of their output parameters is, therefore, of substantial importance for the purposes of the experiments being conducted at these sources. A profound knowledge of the spatial, temporal, spectral, statistical, coherence, and wavefront beam properties may protect us from an unwanted misinterpretation of the experimental data. We present an experimental technique of the spatial (transverse and longitudinal) characterization of the beam profile. Investigating ablative imprints in various materials, we evaluate the spatial properties of the incident beam, namely, the beam waist radius and position, the Rayleigh range, M 2 parameter, and divergence. In this paper, we recall briefly our recent work at the transverse beam profile reconstruction. A newly developed method of the longitudinal beam profile characterization is the main subject of this work. [Copyright &y& Elsevier]

We have performed experiments where DKDP has been irradiated by short (100 fs), laser pulses. Subsequently X-ray pulses with a duration of 100 ps were used as a probe. Time-resolved X-ray diffraction enables monitoring of the transitions between the paraelectric and ferroelectric phases. By recording the intensity of a peak only present in the paraelectric phase, we observe indications of a phase-transition following laser-irradiation of DKDP in the ferroelectric phase. We have estimated the laser heating effect, by measuring the strain (peak shifts) in the diffraction patterns. Furthermore, the orientation of the ferroelectric domains has been observed. In spite of the fact that the temperature did not rise above the Curie temperature, following interaction with this radiation, the polarization of ferroelectric domains was modified. This indicates a mechanism where short pulses impulsively excite phonons, which enable either reversal of entire domains, the shift of domain walls and/or the broadening of the domain wall widths. [Copyright &y& Elsevier]

Abstract. The generation of femtosecond X-ray pulses will have important scientific applications by enabling the direct measurement of atomic motion and structural dynamics in condensed matter on the fundamental time scale of a vibrational period. Interaction of femtosecond laser pulses with relativistic electron beams is an effective approach to generating femtosecond pulses of X-rays. In this paper we present recent results from proof-of-principle experiments in which 300 fs pulses are generated from a synchrotron storage ring by using an ultrashort optical pulse to create femtosecond time structure on the stored electron bunch. A previously demonstrated approach for generating femtosecond X-rays via Thomson scattering between terawatt laser pulses and relativistic electrons is reviewed and compared with storage-ring based schemes. [ABSTRACT FROM AUTHOR]