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Search Publications by: Leticia Pibida (Fed)

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Displaying 1 - 25 of 84

Activity standard and calibrations for 227Th with ingrowing progeny

April 20, 2024
Author(s)
Denis E. Bergeron, Jeffrey T. Cessna, Brittany Broder, Leticia Pibida, Ryan P. Fitzgerald, Morgan DiGiorgio, Elisa Napoli, Brian E. Zimmerman
Thorium-227 was separated from its progeny and standardized for activity by the triple-to-double coincidence ratio (TDCR) method of liquid scintillation counting. Confirmatory liquid scintillation-based measurements were made using efficiency tracing with

Ambient humidity, the overlooked influencer of radioactivity measurements

November 27, 2023
Author(s)
Stefaan Pomme, Michael P. Unterweger, Ryan P. Fitzgerald, Denis E. Bergeron, Leticia Pibida, International Collaboration
When verifying the validity of the exponential-decay law through 128 precise decay rate measurement series at various nuclear laboratories, minor violations have been observed in the shape of annual cycles in the residuals with different amplitudes and

Liquid scintillation efficiencies, gamma-ray emission intensities, and half-life for Gd-153

November 9, 2023
Author(s)
Denis E. Bergeron, Jeffrey T. Cessna, Ryan P. Fitzgerald, Gulakhshan Hamad, Lizbeth Laureano-Perez, Leticia Pibida, Brian E. Zimmerman
Gadolinium-153 was standardized for activity by live-timed anticoincidence counting and an ampoule was submitted to the international reference system (SIR). Absolute emission intensities for the main γ rays were determined with calibrated high-purity

Update of the BIPM comparison BIPM.RI(II)-K1.Co-60 of activity measurements of the radionuclide 60Co to include the 2020 result of the PTB (Germany), the 2020 result of the NIST (United States), the 2020 result of the SMU (Slovakia), the 2021 result of th

March 20, 2023
Author(s)
R Coulon, C Michotte, S Courte, M Nonis, F van Wyngaardt, M Smith, A Bowan, C Keevers, E Clark, M Zarifi, A Ravindra, DB Kulkarni, R Sharma, Marco Capogni, P De Felice, M Capone, P Carconi, A Fazio, C Bobin, R Lins da Silva, A Leiras, J de Almeida Rangel, M Aguiar Leobino da Silva, A Iwahara, Denis E. Bergeron, Jeffrey T. Cessna, Ryan P. Fitzgerald, Lizbeth Laureano-Perez, Leticia Pibida, MW Van Rooy, Jf Lubbe, MJ van Staden, John Keightley, A Pearce, N Ramirez, E Bendall, S Collins, T Ziemek, E Lech, P Saganowski, M Czudek, A Listkowska, O Nahle, Karsten Kossert, M Takacs, M Krivosik, I Bonkova
Since 1976, 30 laboratories have submitted 85 samples of 60Co to the International Reference System (SIR) for activity comparison at the Bureau International des Poids et Mesures (BIPM), with comparison identi_er BIPM.RI(II)-K1.Co-60. Recently, the PTB

Primary standardization of 212Pb activity by liquid scintillation counting

September 22, 2022
Author(s)
Denis E. Bergeron, Jeffrey T. Cessna, Ryan P. Fitzgerald, Lizbeth Laureano-Perez, Leticia Pibida, Brian E. Zimmerman
An activity standard for 212Pb in equilibrium with its progeny was realized, based on triple-to-double coincidence ratio (TDCR) liquid scintillation (LS) counting. A Monte Carlo-based approach to estimating uncertainties due to nuclear decay data

Characterization Method of Ionization Chamber Type Detectors

February 25, 2022
Author(s)
Leticia Pibida, Ronaldo Minniti, Miles McCord
A wide variability in accuracy exists among commercial radiation detection instruments used to measure exposure rate or ambient dose equivalent rate. These instruments are used to measure both the radiation background and the radiation field produced by

BIPM comparison BIPM.RI(II)-K1.Gd-153 of activity measurements of the radionuclide 153Gd to include the 2020 result of the NIST (United States)

November 25, 2021
Author(s)
Denis E. Bergeron, Jeffrey T. Cessna, Ryan P. Fitzgerald, Lizbeth Laureano-Perez, Leticia Pibida, Carine Michotte, S Courte, M Nonis, R Coulon, S Judge
Since 1988, 3 laboratories have submitted 5 samples of 153Gd to the International Reference System (SIR) for activity comparison at the Bureau International des Poids et Mesures (BIPM), with comparison identifier BIPM.RI(II)- K1.Gd-153. Recently, the NIST

Bilateral comparison of the activity concentration for a standardized 137Cs solution between the National Institute of Standards Technology (NIST) and the National Institute of Nuclear Research (ININ)

November 10, 2021
Author(s)
Leticia Pibida, Willie Regits, Olga Garcia Diaz, Lucia Martinez Ayala, Hector Mendoza Nava
This paper summarized the results of the activity concentration of a 137Cs solution performed as a bilateral comparison between the National Institute of Standards and Technology (NIST) in the United States of America and the National Institute of Nuclear

Recalibration Intervals for Radiation Detection Instruments

April 2, 2021
Author(s)
Leticia Pibida, Ben Estes, Manuel Mejias, Gladys Klemic
In this work we provide a summary of the National Conference of Standards Laboratories (NCSL) Recommended Practice RP-1 calibration interval analysis method, and examples of the method applied to three sets of available NIST data (two models of radiation

Ra-224 activity, half-life, and 241 keV gamma ray absolute emission intensity: a NIST-NPL bilateral comparison

December 31, 2020
Author(s)
Denis E. Bergeron, Sean Collins, Leticia Pibida, Jeffrey T. Cessna, Ryan P. Fitzgerald, Brian E. Zimmerman, Peter Ivanov, John Keightley, Elisa Napoli
The national metrology institutes for the United Kingdom and the United States have compared activity standards for 224Ra, an -particle emitter of interest as the basis for therapeutic radiopharmaceuticals. Solutions of 224RaCl2 were assayed by absolute

False Alarm Testing for Radiation Detection Systems

October 2, 2020
Author(s)
Dennis D. Leber, Leticia S. Pibida
An operator of a radiation detection system that displays a high rate of false alarms may be- come desensitized to these alarms. This action is known as alarm fatigue and can have detri- mental results as the operator may cease to respond to what may be

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