Accession Number : AD0749421

Title :   Elemental and Trace Analysis by Energy Dispersive X-Ray Spectrometry.

Descriptive Note : Master's thesis,

Corporate Author : AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OHIO SCHOOL OF ENGINEERING

Personal Author(s) : Hockemeier,John M.

Report Date : MAR 1972

Pagination or Media Count : 63

Abstract : In the study energy-dispersive X-ray spectrometry is examined as an analytical tool for elemental and trace quantity analysis. Characteristic X-rays are generated in samples by gamma and X-ray emitting radioisotopes and by high energy protons. Quantitative analysis, based upon empirical techniques derived from wavelength-dispersion methods gives elemental composition values to within approximately 1% of chemically analyzed standards. In proton activation of X-rays empirical equations and experimentals values result in actual detection of trace quantities of elements to the nanogram level. Extrapolations of detected values indicate that the method is capable of detecting quantities to the picogram level. A vacuum chamber, designed, built and adapted to a 2 MeV Van de Graaff accelerator is used as the target chamber. The targets are thin (200 microgram/square cm) carbon foils on which are deposited the specimens under investigation. An atmospheric sample is a typical specimen examined. Trace quantities of elements such as bromine, lead, mercury, gallium and others are detected in the nanogram range. (Author)

Descriptors :   (*X RAY SPECTROSCOPY, *MICROANALYSIS), PHOTON BOMBARDMENT, GAMMA EMISSION, BROMINE, LEAD(METAL), MERCURY, GALLIUM, VAN DE GRAAFF GENERATORS, THESES, RADIOACTIVE ISOTOPES

Subject Categories : Atomic and Molecular Physics and Spectroscopy

Distribution Statement : APPROVED FOR PUBLIC RELEASE