title: Soft X-ray scanning transmission X-ray microscopy (STXM) of actinide particles.
abstract: A descriptive account is given of our most recent research on the actinide dioxides with the Advanced Light Source Molecular Environmental Science (ALS-MES) Beamline 11.0.2 soft X-ray scanning transmission X-ray microscope (STXM) at the Lawrence Berkeley National Laboratory (LBNL). The ALS-MES STXM permits near-edge X-ray absorption fine structure (NEXAFS) and imaging with 30-nm spatial resolution. The first STXM spectromicroscopy NEXAFS spectra at the actinide 4d5/2 edges of the imaged transuranic particles, NpO2 and PuO2, have been obtained. Radiation damage induced by the STXM was observed in the investigation of a mixed oxidation state particle (Np(V,VI)) and was minimized during collection of the actual spectra at the 4d5/2 edge of the Np(V,VI) solid. A plutonium elemental map was obtained from an irregular PuO2 particle with the dimensions of 650 x 650 nm. The Pu 4d5/2 NEXAFS spectra were collected at several different locations from the PuO2 particle and were identical. A representative oxygen K-edge spectrum from UO2 was collected and resembles the oxygen K-edge from the bulk material. The unique and current performance of the ALS-MES STXM at extremely low energies (ca. 100 eV) that may permit the successful measurement of the actinide 5d edge is documented. Finally, the potential of STXM as a tool for actinide investigations is briefly discussed.
authors: The Glenn T. Seaborg Center, Chemical Sciences Division, Lawrence Berkeley National Laboratory, One Cyclotron Road, Berkeley, CA 94720, USA.
authors: Hans J
authors: HJ
authors: Nilsson
authors: Tolek
authors: T
authors: Tyliszczak
authors: Richard E
authors: RE
authors: Wilson
authors: Lars
authors: L
authors: Werme
authors: David K
authors: DK
authors: Shuh
mesh_terms: D008671:Actinoid Series Elements / Q000737:chemistry*; D000327:Adsorption; D001672:Biocompatible Materials / Q000737:chemistry*; D015374:Biosensing Techniques; D008855:Microscopy, Electron, Scanning / Q000379:methods*; D009405:Neptunium / Q000737:chemistry; D010084:Oxidation-Reduction; D010316:Particle Size; D017785:Photons; D011005:Plutonium / Q000737:chemistry; D017974:Uranium Compounds / Q000737:chemistry; D014965:X-Rays
chemical_list: D008671:Actinoid Series Elements; D001672:Biocompatible Materials; D017974:Uranium Compounds; C026885:plutonium dioxide; D011005:Plutonium; D009405:Neptunium; C012597:uranium dioxide