Soft X-ray Synchrotron Radiation Investigations of Actinide Materials Systems Utilizing X-ray Emission Spectroscopy and
- PDF / 192,091 Bytes
- 6 Pages / 612 x 792 pts (letter) Page_size
- 84 Downloads / 193 Views
DD3.10.1
Soft X-ray Synchrotron Radiation Investigations of Actinide Materials Systems Utilizing X-ray Emission Spectroscopy and Resonant Inelastic X-ray Scattering D. K. Shuh,1 S. M. Butorin,2 J.-H. Guo,3 and J. Nordgren2 1 Chemical Sciences Division, Lawrence Berkeley National Laboratory (LBNL), Berkeley, California 94720 USA 2 Department of Physics, Uppsala University, Box 530, S-751 21 Uppsala, Sweden 3 Advanced Light Source Division, Lawrence Berkeley National Laboratory (LBNL), Berkeley, California 94720 USA ABSTRACT Synchrotron radiation (SR) methods have been utilized with increasing frequency over the past several years to study topics in actinide science, ranging from those of a fundamental nature to those that address a specifically-targeted technical need. In particular, the emergence of microspectroscopic and fluorescence-based techniques have permitted investigations of actinide materials at sources of soft x-ray SR. Spectroscopic techniques with fluorescence-based detection are useful for actinide investigations since they are sensitive to small amounts of material and the information sampling depth may be varied. These characteristics also serve to simplify both sample preparation and safety considerations. Examples of investigations using these fluorescence techniques will be described along with their results, as well as the prospects for future investigations utilizing these methodologies. INTRODUCTION The state-of-the-art understanding of the electronic structure, surface chemistry, and interfacial properties of actinide materials lags substantially behind that of other materials systems in part because of radiological safety issues that have prevented the actinide science community from taking advantage of SR methodologies in the soft x-ray region, which revolutionized the approach to surface chemistry/physics twenty years ago. A major unresolved question in the properties of actinide materials is the nature of the 5f electrons and their exact role in chemical bonding which determines their materials chemistry. The radiological safety concerns arise due to the difficulty of safely handling, preparing, and performing measurements on actinide materials under vacuum shared with beamlines and soft x-ray SR storage rings. One of the most powerful techniques for studying electronic structure is photoelectron spectroscopy employing tunable soft x-ray SR. Determining the features attributable solely to 5felectrons is difficult if a photoelectron spectrum is collected at a single photon energy. The ability to perform resonant photoemission measurements at the 5d threshold, where 5f emission is selectively enhanced, is crucial to better understand actinide materials. Tunable light near the actinide 5d absorption edges (~98 eV for U) makes the identification possible due to the large Fano resonances. Recently, significant results from resonant photoemission investigations of metallic Pu have been obtained at the Advanced Light Source (ALS), as well as a tunable light source.[1-3] However, soft x-ray SR ph
Data Loading...
