학술논문
Bootstrap estimation of the effect of instrument response function uncertainty on the reconstruction of fusion neutron sources.
Document Type
Academic Journal
Author
Lamb KM; Los Alamos National Laboratory, Los Alamos, New Mexico 87544, USA.; Geppert-Kleinrath V; Los Alamos National Laboratory, Los Alamos, New Mexico 87544, USA.; Birge NW; Los Alamos National Laboratory, Los Alamos, New Mexico 87544, USA.; Danly CR; Los Alamos National Laboratory, Los Alamos, New Mexico 87544, USA.; Divol L; Lawrence-Livermore National Laboratory, Livermore, California 94550, USA.; Fittinghoff DN; Lawrence-Livermore National Laboratory, Livermore, California 94550, USA.; Freeman MS; Los Alamos National Laboratory, Los Alamos, New Mexico 87544, USA.; Pak AE; Lawrence-Livermore National Laboratory, Livermore, California 94550, USA.; Wilde CH; Los Alamos National Laboratory, Los Alamos, New Mexico 87544, USA.; Zylstra AB; Lawrence-Livermore National Laboratory, Livermore, California 94550, USA.; Volegov PL; Los Alamos National Laboratory, Los Alamos, New Mexico 87544, USA.
Source
Publisher: American Institute Of Physics Country of Publication: United States NLM ID: 0405571 Publication Model: Print Cited Medium: Internet ISSN: 1089-7623 (Electronic) Linking ISSN: 00346748 NLM ISO Abbreviation: Rev Sci Instrum Subsets: PubMed not MEDLINE; MEDLINE
Subject
Language
English
Abstract
Neutron imagers are important diagnostics for the inertial confinement fusion implosions at the National Ignition Facility. They provide two- and three-dimensional reconstructions of the neutron source shape that are key indicators of the overall performance. To interpret the shape results properly, it is critical to estimate the uncertainty in those reconstructions. There are two main sources of uncertainties: limited neutron statistics, leading to random errors in the reconstructed images, and incomplete knowledge of the instrument response function (the pinhole-dependent point spread function). While the statistical errors dominate the uncertainty for lower yield deuterium-tritium (DT) shots, errors due to the instrument response function dominate the uncertainty for DT yields on the order of 10 16 neutrons or higher. In this work, a bootstrapping method estimates the uncertainty in a reconstructed image due to the incomplete knowledge of the instrument response function. The main reconstruction is created from the fixed collection of pinhole images that are best aligned with the neutron source. Additional reconstructions are then built using subsets of that collection of images. Variations in the shapes of these additional reconstructions originate solely from uncertainties in the instrument response function, allowing us to use them to provide an additional systematic uncertainty estimate.