U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Search Publications by: Leticia Pibida (Fed)

Search Title, Abstract, Conference, Citation, Keyword or Author
Displaying 26 - 50 of 166

Comparing Instruments

September 30, 2020
Author(s)
James H. Yen, Dennis D. Leber, Leticia S. Pibida
This document details methods to compare instrument performance. Comparison methods for instruments outputting binary (0-1) responses as well as for instruments outputting continuous numeric responses are shown, first for two instruments and then for

228Th breakthrough in 224Ra samples: what can we know and when can we know it?

April 6, 2020
Author(s)
Denis E. Bergeron, Ryan P. Fitzgerald, Leticia S. Pibida
Recent renewed interest in radium-224 (224Ra) as a radiotherapeutic agent prompted the development of a primary standard for activity at the National Institute of Standards and Technology (NIST). The 224Ra decay chain includes the emission four alpha

Guidebook for Standards-Based Testing of Radiation-Detection Systems

November 12, 2019
Author(s)
Leticia S. Pibida, Chritina Forrested, Peter Chiaro, Don Potter
This guide describes the test setups and processes needed to perform standards-based testing of radiological and nuclear detection systems. This guide is intended to reduce the potential for misinterpretation of performance requirements, test methods, and

Primary standardization of Ra-224 activity by liquid scintillation counting

October 11, 2019
Author(s)
Denis E. Bergeron, Jeffrey T. Cessna, Ryan P. Fitzgerald, Brian E. Zimmerman, Lizbeth Laureano-Perez, Ronald Colle, Leticia S. Pibida, Elisa Napoli
A standard for 224Ra activity has been developed, based on triple-to-double coincidence ratio (TDCR) liquid scintillation (LS) counting. The standard was confirmed by efficiency tracing and 4παβ(LS)-γ(NaI(Tl)) anticoincidence counting, as well as by 4πγ

Preparation and calibration of a Protactinium-231 reference material

August 22, 2019
Author(s)
Richard Essex, Ross W. Williams, Kerri C. Treinen, Ronald Colle, Ryan P. Fitzgerald, Raphael Galea, John Keightley, Jerome LaRosa, Lizbeth Laureano-Perez, Svetlana Nour, Leticia Pibida
A 231Pa reference material has been characterized for amount of Pa. This reference material is primarily intended for calibration of 233Pa tracers produced for 231Pa - 235U model age measurements associated with nuclear forensics and nuclear safeguards

Standardization of I-124 by three liquid scintillation-based methods

August 9, 2019
Author(s)
Denis E. Bergeron, Leticia S. Pibida, Brian E. Zimmerman, Jeffrey T. Cessna, Ryan P. Fitzgerald
A solution of 124I was standardized for activity by 4πβ(LS)-γ(NaI) live-timed anticoincidence (LTAC) counting, with confirmatory measurements by triple-to-double coincidence ratio (TDCR) and CIEMAT-NIST efficiency tracing (CNET) liquid scintillation

Confirming a Performance Threshold with a Binary Experimental Response

July 15, 2019
Author(s)
Dennis D. Leber, Leticia S. Pibida, Alexander L. Enders
Often, experimenters wish to confirm that a test artifact meets some predefined, fixed performance criterion or claim. For example: does the newly formulated pharmaceutical reduce the disease rate by 10 %; will the composite overwrapped pressure vessel

PRIMARY STANDARDIZATION OF THE MASSIC ACTIVITY OF A PROTACTINIUM-233 SOLUTION

August 23, 2018
Author(s)
Ryan P. Fitzgerald, Leticia S. Pibida
Protactinium-233 (233Pa) is used as a tracer for radiochemical analysis and is of particular interest as an isotope dilution mass spectrometry (IDMS) spike for 231Pa/235U radio- chronometry. To this end, we present massic activity determinations by two

Measurements of scatter peaks in 137Cs and 60Co sources

June 28, 2018
Author(s)
Leticia S. Pibida
The results of the testing of radiation detection instruments with radionuclide identification capabilities will depended on the sources used for the tests. High resolution spectra need to be acquired to determine all the observable peaks in the source

Standardization of 64Cu activity

May 25, 2018
Author(s)
Denis E. Bergeron, Jeffrey T. Cessna, Ryan P. Fitzgerald, Leticia S. Pibida, Brian E. Zimmerman
The complex decay scheme that makes 64Cu promising as both an imaging and therapeutic agent in medicine also makes the absolute measurement of its activity challenging. The National Institute of Standards and Technology (NIST) has completed a primary