Project Title: Radiochemical Analysis by High Sensitivity Dual-Optic Micro X-ray Fluorescence

Havrilla, George J. ; Gao, Ning

Los Alamos National Laboratory

关键词: Bremsstrahlung;    12 Management Of Radioactive Wastes, And Non-Radioactive Wastes From Nuclear Facilities;    Fluorescence;    37 Inorganic, Organic, Physical And Analytical Chemistry;    Excitation;   

DOI  :  10.2172/835000
RP-ID  :  EMSP-81967-2002
RP-ID  :  FG07-01ER63280
RP-ID  :  835000

美国|英语

来源: UNT Digital Library

【 摘 要 】

A novel dual-optic micro X-ray fluorescence instrument will be developed to do radiochemical analysis of high-level radioactive wastes at DOE sites such as Savannah River Site and Hanford. This concept incorporates new X-ray optical elements such as monolithic polycapillaries and double bent crystals, which focus X-rays. The polycapillary optic can be used to focus X-rays emitted by the X-ray tube thereby increasing the X-ray flux on the sample over 1000 times. Polycapillaries will also be used to collect the X-rays from the excitation site and screen the radiation background from the radioactive species in the specimen. This dual-optic approach significantly reduces the background and increases the analyte signal thereby increasing the sensitivity of the analysis. A doubly bent crystal used as the focusing optic produces focused monochromatic X-ray excitation, which eliminates the bremsstrahlung background from the X-ray source. The coupling of the doubly bent crystal for monochromatic excitation with a polycapillary for signal collection can effectively eliminate the noise background and radiation background from the specimen. The integration of these X-ray optics increases the signal-to-noise and thereby increases the sensitivity of the analysis for low-level analytes. This work will address a key need for radiochemical analysis of high-level waste using a non-destructive, multi-element, and rapid method in a radiation environment. There is significant potential that this instrumentation could be capable of on-line analysis for process waste stream characterization at DOE sites.