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Luttman, Aaron

Publications and source records attributed to Luttman, Aaron.

14 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2019

Quantifying Spatially Varying Blur in X-ray Radiographic Imaging Systems

Two goals of quantitative analysis of radiographic data from dynamic material experiments are to identify edge locations and infer material density. Understanding the systematic effect of blur of the imaging system through calibration imagery is the fist step to quantifying, modeling, and eventually mitigating its effect. If modeling geometry and assumptions can be expressed through operator transformations, this leads to natural modifications of the likelihood and prior in a Bayesian formulation of the inverse problem.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2019

Tomographic Reconstruction of the Neutron Time-Energy Spectrum from a Dense Plasma Focus

A dense plasma focus (DPF) nuclear fusion generator is an attractive pulsed neutron source in many applications, due to its relatively large neutron yield, produced in a short time duration. In order to design a DPF that generates neutrons within a specified time profile, or generates a neutron energy spectrum with specific properties, it is necessary to understand and be able to fully characterize the results of the fusion process releasing the neutrons. The time-energy spectrum of fusion neutrons is an ideal quantity to use to validate multiphysics codes that simulate the pinch and fusion processes, because it is a quantity that requires the physics of each of the stages leading up to and ending in the fusion reaction to be simulated correctly. In particular, since DPF fusion neutrons are not monoenergetic – and there can often be several fusion pinches creating neutrons – a computer simulation matching high quality neutron spectrum measurements provides great confidence in the fidelity of the simulation. In order to make such a comparison, it is first necessary to have quality measurements from which to infer the spectrum. In this work we pose neutron spectroscopy as the classical tomographic inverse problem from neutron time of flight data at multiple distances, but enhanced by using detector pairs designed to reduce the scatter background and with an additional measurement of the time profile of the fusion pinch near its source. The detector pairs enhance the quality of the time of flight measurements and the additional constraint posed by the measured time profile allows for temporal resolution in the spectrum reconstruction that is equal to the measurement resolution, which can be subnanosecond, and energy resolution in the 10’s of keV, without the problem being underconstrained. We present results from a Deuterium-fueled DPF at the U.S. Department of Energy’s Nevada National Security Site and show that we can infer the time-energy spectrum from our measurements for both single and multi-pinch fusion reactions with equal fidelity.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
DOE OSTI2018

Dense Plasma Focus Technology and Applications at the Nevada National Security Site

The Nevada National Security Site (NNSS) is used by U.S. national laboratories to conduct nuclear security experiments. Among these investigations is the development and deployment of Dense Plasma Focus (DPF) neutron source technology. These sources include a Megajoule-class source and a portable 1-kilojoule class source both of which fuse deuterium to produce neutrons, and a 300 kilojoule-class source that fuses deuterium and tritium. The applications currently under investigation are reactivity measurements and detection of radiological material.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2018

Interdependent Networks

This presentation will be given at the FY18 NA-22 SWRD program review at LANL.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2018

Mathematical Models for Adaptive Multi-modal Sensing

Project Proposal for Graduate Student Program - This is a project proposal for a group of graduate students in the Institute for Mathematics and Its Applications Math-to-Industry Bootcamp.

97 MATHEMATICS AND COMPUTING↗