Femtosecond X-ray Diffraction: Applications for Laser-Irradiated Materials

Journal Article · Thu Sep 10 00:00:00 EDT 2009 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.3241197· OSTI ID:21344620

Wark, Justin S ^[1]

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1. Department of Physics, Clarendon Laboratory, University of Oxford, Parks Road, Oxford, OX1 3PU (United Kingdom)

Over the past few years short pulse x-ray diffraction at the nanosecond and picosecond level has become an established technique in many high-power laser laboratories for interrogating the lattice response of laser-perturbed and shocked matter, and is now finding applications in diagnosing the state of crystalline materials subject to quasi-isentropic compression. We review some of the previous results obtained in this area, for example the direct observation of coherent phonons, the first direct confirmation of the alpha-epsilon transition in shocked iron, and recent measurements indicating that the strength of matter can be measured at shock pressures exceeding a Mbar. The majority of sources used to date have been laser-plasma based, with some work being performed using 3{sup rd} generation synchrotron sources. However, the development of 4{sup th} generation x-ray free-electron lasers, such as LCLS, afford many new opportunities, with pulse lengths in the femtosecond regime. The extremely low divergence and monochromatic nature of the LCLS beam make it well suited to study compressed polycrystalline matter, especially samples with small grain sizes. At extremely short pulse lengths, such that the pulse is shorter than an x-ray extinction depth traversal time, the diffraction process itself becomes time-dependent, and in certain cases the full wave-field solution will be required, particularly if the matter itself is being rapidly perturbed, as will occur if the intense x-ray radiation is used to create warm dense matter, as in recent experiments on FLASH at DESY.

• OSTI ID: 21344620
• Journal Information: AIP Conference Proceedings, Vol. 1161, Issue 1; Conference: 16. international conference on atomic processes in plasmas, Monterey, CA (United States), 22-26 Mar 2009; Other Information: DOI: 10.1063/1.3241197; (c) 2009 American Institute of Physics; ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
COMPRESSION
DEPTH
FREE ELECTRON LASERS
GRAIN SIZE
GRANULAR MATERIALS
IRON
ISENTROPIC PROCESSES
LASER RADIATION
MONOCHROMATIC RADIATION
PHONONS
POLYCRYSTALS
PULSED IRRADIATION
SHOCK WAVES
TIME DEPENDENCE
X-RAY DIFFRACTION
COHERENT SCATTERING
CRYSTALS
DIFFRACTION
DIMENSIONS
ELECTROMAGNETIC RADIATION
ELEMENTS
IRRADIATION
LASERS
MATERIALS
METALS
MICROSTRUCTURE
QUASI PARTICLES
RADIATIONS
SCATTERING
SIZE
TRANSITION ELEMENTS