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Mercer, David James

Publications and source records attributed to Mercer, David James.

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DOE OSTI2023

DOE Radiological Triage Program: Analyst Open Book Exam 2021

This document contains the open book exam for Radiological Triage Program Analysts for Los Alamos National Laboratory. "The following questions test your knowledge relevant to the DOE Radiological Triage program. There is no time limit, and you may use any reference materials or software you like. You may discuss with other analysts but please show your own work. Spectra are provided in electronic form. There are 10 questions and up to 1 point of extra credit is available. A score of 80% is required to pass. Please send your answers in any convenient form to Mercer@LANL.gov."

96 KNOWLEDGE MANAGEMENT AND PRESERVATION↗
DOE OSTI2023

DOE Radiological Triage Program Analyst Open Book Exam 2022

This document contains the 2022 open book examination for Radiological Triage Program Analysts for Los Alamos National Laboratory. "The following questions test your knowledge relevant to the DOE Radiological Triage program. There is no time limit, you may use any reference materials or software you like, and you may discuss with other analysts. No electronic spectra are provided or needed. Please send your answers in any convenient form to Mercer@LANL.gov. You may also take the exam using Survey Monkey (which will provide immediate feedback). A score of 80% is required to pass. There are 25 multiple-choice questions each worth 1 point."

96 KNOWLEDGE MANAGEMENT AND PRESERVATION↗
DOE OSTI2023

Correlated Signal Analysis for Nuclear Emergency Response

In the context of nuclear emergency response (NER) scenarios, the critical task is to quickly identify a "black box" as a potential threat, as failing to do so could have catastrophic consequences. Techniques for passive assay of a “black box” typically include gamma-ray spectroscopy and neutron coincidence/multiplicity counting. However, there are significant challenges associated with these type of measurements. First, the presence of intervening materials can obstruct the detection of relevant signatures. Second, the presence of strong non-fission neutron sources, like (α, n) emitters, can add uncertainties to the neutron multiplicity analysis. In our LDRD-MFR Phase II work, a portable neutron spectrometer, called the Compact Fast Neutron Spectrometer (CFNS), was developed for NER applications. The CFNS system leverages information-rich neutron energy spectra to derive actionable information. This work investigates the use of correlated signals in the CFNS from special nuclear material (SNM) to characterize physical properties, such as intervening shielding material and fission to non-fission neutron contributions. In this report, the Phase II results from bulk SNM measurements at the National Criticality Experiments Research Center (NCERC) are briefly discussed along with the motivation for this work. Afterwards, simulations using the MCNPX-PoliMi transport code are discussed, which were used to expand our correlated signal study. Signal triggered analysis for neutron multiplicity extraction will also be discussed. Lastly, the use neutron-photon correlations for intervening material identification are shown, along with the use of correlated neutron energy spectra for α-ratio extraction.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗