M 4, 5 edge studies on Uranium (BIGRAD consortium)

  • Mosselmans, J. Frederick W (Principal Investigator)
  • Shaw, Samuel (Co-investigator)
  • Livens, Francis (Co-investigator)
  • Bots, Pieter (Co-investigator)
  • Williamson, Adam (Co-investigator)
  • Law, Gareth (Co-investigator)
  • Lloyd, Jonathan R. (Co-investigator)
  • Marshall, Timothy A. (Co-investigator)
  • Coker, Victoria S. (Co-investigator)
  • Morris, Katherine (Co-investigator)

Project: ResearchEquipment Only

Description

Beamtime at the micro XAS / XRF beamline (I18) at Diamond Light Source, funded through Diamond Light Source.

Abstract of research proposal:
After a trial experiment on I18, we have evidence that the M4,5 edges of U are clearer indicators of U oxidation state than L-edge data. We want to continue this model study by measuring a the M4 and M5 edges of a set of differently ligated U standards to check that the limited dataset we have is not "special" and the the results are relatively transferable.
If we verify the validity of the method we would intend further studies in particular possible time frozen studies in attempts to see possible U(V) intermediates.
The oxidation state of U in contact with bacteria and mineral phases is an important parameter with respect to its transport properties. As part of the Bigrad experimental studies we are determining U interactions with minerals relevant to a UK nuclear repository often by L3,2 XAFS studies but L-edge oxidation state determination is hindered by the large core hole width.
StatusFinished
Effective start/end date6/02/136/02/13