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Search Publications by: Lizbeth Laureano-Perez (Fed)

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Displaying 26 - 44 of 44

Development of an Ultra-Pure, Carrier-Free 209Po Solution Standard

July 23, 2015
Author(s)
Ronald Colle, Ryan P. Fitzgerald, Lizbeth Laureano-Perez
Ultra-pure, carrier-free 209Po solution standards have been prepared and standardized for their massic alpha-particle emission rate. The standards, which will be disseminated by the National Institute of Standards and Technology (NIST) as Standard

The Half-Life of 209Po : Revisited

August 13, 2014
Author(s)
Ronald Colle, Ryan P. Fitzgerald, Lizbeth Laureano-Perez
A substantial 25 % error in the then known and accepted (102  5) year half-life of 209Po was reported on in 2007. This error was detected from decay data from two separate primary standardizations of a 209Po solution standard, which were performed

Standardization of 237Np

December 4, 2013
Author(s)
Lizbeth Laureano-Perez, Ryan P. Fitzgerald, Ronald Colle
The standardization of 237Np was investigated. The certified massic activity for 237Np was obtained by 4 liquid scintillation (LS) counting with correction for the 233Pa daughter using the CIEMAT/NIST efficiency tracing method using a 3H standard

Micelle size effect on Fe-55 Liquid Scintillation Efficiency

December 1, 2013
Author(s)
Denis E. Bergeron, Lizbeth Laureano-Perez
We used efficiency tracing techniques to study the micelle size effect on liquid scintillation counting of the low-energy Auger electron emitter, 55Fe. We determined micelle hydrodynamic diameters for specific LS cocktails via dynamic light scattering, and

Investigation into the Standardization of Tc-99

July 30, 2010
Author(s)
Lizbeth Laureano-Perez, Ronald Colle, Ryan P. Fitzgerald, Brian E. Zimmerman, Lonnie T. Cumberland
The standardization of 99Tc by several primary methods was investigated. This was performed to support a new 99Tc transfer standard that has been developed and will be disseminated by the National Institute of Standards and Technology (NIST) as Standard

A New Primary Standardization of Th-229

January 7, 2010
Author(s)
Ryan P. Fitzgerald, Lizbeth Laureano-Perez, Michelle M. Hammond, Leticia S. Pibida, Svetlana Nour, Brian E. Zimmerman
The National Institute of Standards and Technology (NIST) has certified a high-purity Th-229 Standard Reference Material as SRM 4328C, based on live-timed 4-pi alpha,beta-gamma anticoincidence counting (LTAC) of the equilibrium solution. The LTAC system