Award Date

2009

Degree Type

Thesis

Degree Name

Master of Science in Health Physics

Department

Health Physics and Diagnostic Sciences

Advisor 1

Ralf Sudowe, Committee Chair

First Committee Member

Steen Madsen

Second Committee Member

Phillip Patton

Graduate Faculty Representative

Vernon Hodge

Number of Pages

114

Abstract

Microprecipitation has become one of the most widely used sample preparation techniques for alpha spectroscopy. Many factors during the precipitation process can affect the yield and energy resolution by adding unwanted mass to the sample. Current applications in nuclear forensics call for an optimization of energy resolution and yield in order to improve identification and quantify specific radionuclides. The purpose of this research is to determine the optimal parameters used for microprecipitation. The optimal solution temperature, precipitation time, carrier amount, and hydrofluoric acid amount are used to investigate the influence of varying the type of carrier, as well as, the addition of hydrochloric acid and other radionuclides. The determined optimal parameter was 0.0125mg of cerium with 1mL of hydrofluoric acid at room temperature for 30 minutes. The optimal carrier concentration for lanthanum was 0.005mg while neodymium was 0.0025mg. A multinuclide solution had no impact on the results; however the addition of 20 mL of HCl should be reduced before performing microprecipitation. The homogeneity of the radionuclides deposited onto the source sample was determined by using autoradiography. The optimal parameters of microprecipitation, in addition to the deposition pattern of the radionuclide, can be used to improve identification and quantification of radionuclides for nuclear forensics applications.

Keywords

Alpha spectroscopy; Crime scene investigations; Forensic techniques; Microprecipitation; Nuclear forensics; Precipitation; Radiochemistry; Source preparation

Disciplines

Analytical Chemistry | Criminology | Evidence | Law Enforcement and Corrections | Nuclear | Radiochemistry

Language

English