July 13, 2018

Colloquium Speaker: Captain Drake Brewster


Captain Drake Brewster is an active duty officer with the United States Army.  His current assignment is as an instructor in the Department of Physics and Nuclear Engineering at the United States Military Academy at West Point.  Drake recently completed a Master’s of Science in Physics from the Naval Postgraduate School in Monterey, California.  His master’s thesis concentrated on actinide isotope ratio measurements in collaboration with Lawrence Livermore National Laboratory.




Colloquium Topic: Actinide Isotope Ratios Measured by Resonance Ionization Mass Spectrometry: Optimization of Ionization Schemes and Demonstration Using Nuclear Fallout

Resonance Ionization Mass Spectrometry is a technology for analysis of isotopic composition of samples that was developed as early as the 1980s. Since its development, technological advancements have enabled instruments such as the Laser Ionization of Neutrals instrument at Lawrence Livermore National Laboratory to measure isotope ratios with an accuracy within one percent at high measurement efficiency while remaining relatively free of isobaric interferences. The instrument has recently been successfully used to quantify uranium isotope ratios in nuclear fallout debris. The work covered in this talk explores recent developments in simplified laser excitation schemes, surface oxidation reduction, and future research opportunities in isotope ratio measurements.