High Energy Beamlines

Contact Tel: +33(0)47688 +ext Fax: +33(0)476882542 Veijo Honkimäki, Scientist in Charge 2725 Marco di Michiel, Beamline Operations Manager 2123 Diego Pontoni, Scientist 2817 Thomas Buslaps, Materials Science Group Beamline Operations Manager 2684 Control hutches: ID15A ID15B 2606 2605 Email to ID15

Synopsis

ID15A and ID15B beamlines are dedicated to applications using very high energy x-ray radiation up to several hundred keV. At present the two main areas of user activities are engineering materials research and studies of surfaces and buried interfaces. ID15A holds three experimental setups: energy dispersive diffraction (EDD) for depth resolved strain studies, fast micro-tomography for in-situ and time resolved imaging studies and high energy micro-diffraction (HEMD) setup for the studies of buried interfaces. ID15B holds the angular dispersive diffraction (ADD) setup using large area detector and high resolution Compton spectrometer. The concept of the beamlines is to keep scientific options open and retain flexibility to exploit the unique properties of very hard x-rays:

• large penetration depth

• large Ewald spheres

• access to very high momentum transfer

• long extinction lengths

• small radiation doses

Technical overview

Layout of the beamline: ID15A can take white or monochromatic radiation and ID15B takes monochromatic radiation (30, 60 or 90keV).

The x-ray optics and beamline layout, shown in Figure 1, are designed to operate two independent branches simultaneously. ID15A and ID15B share the expertise and equipment, and have always been operated more as a single entity than as isolated facilities.

The ID15 insertion straight section holds a 7 pole 1.84T asymmetric multipole wiggler (AMPW) and a in-vacuum undulator (U22). The critical energy of AMPW is 44keV, and the useful spectrum extends up to 500keV. Below 120keV U22 gives a superior flux. The wiggler gives circularly polarized radiation off-axis so that elastic and inelastic magnetic scattering experiments are feasible. The beamlines operate usually between 70 and 400keV, which contrasts sharply with conventional x-ray terminology, where anything greater than 20keV is considered exotically high. The x-ray energies below 30keV are not available at ID15.

• ID15A technical details

• ID15B technical details

The fluxes of the AMPW (blue) and U22 (green) at the orbit through (1x1)mm² pinhole at 60m distance.

Scientific applications

• Research at ID15A

Since 1999 there have been more that 250 user experiments and about 300 publications based on experiments done at ID15. They cover a wide area of applications and it is impossible to give a full description of them. The following sections concentrate on the most important scientific fields which have developed during this period.

• Combined diffraction and tomography studies
  

• Void formation in Nb₃Sn superconductors
• Creep damage

• Imaging

• Granular materials
• Metallic glass foams
• Phase contrast imaging
• Planar lenses for high energy x–ray micro- and nano-focusing

• Materials science engineering
• Crack tips
• Peening
• In-situ loading of Zircaloy-2

• Surface and interface studies
• Water gap and interface melting of ice
• Investigation of the Schottky contact interface
• Crystal truncation rod measurements using high energy x-rays and an area detector

• Research at ID15B

• Diffraction studies

• Strain on amorphous materials
• Studies on transparent conducting oxides and hydroxyapatites
• Diffuse scattering measurements from binary alloys
• Anomalous diffraction at high energy for macromolecular crystallography
• Studies of friction stir welds

• Inelastic scattering studies

• Fermi surface nesting in Ba_1−xK_xBiO₃
• Correlation of hydrogen bond lengths and angles in liquid water

Complementary information

• Library
• User office