Quantification of uncertainty in photon source spot size inference during laser-driven radiography experiments at TRIDENT

Technical Report · Tue Oct 24 00:00:00 EDT 2017

DOI:https://doi.org/10.2172/1402669· OSTI ID:1402669

Tobias, Benjamin John ^[1]; Palaniyappan, Sasikumar ^[1]; Gautier, Donald Cort ^[1]; Mendez, Jacob ^[1]; Burris-Mog, Trevor John ^[1]; Huang, Chengkun K. ^[1]; Favalli, Andrea ^[1]; Hunter, James F. ^[1]; Espy, Michelle E. ^[1]; Schmidt, Derek William ^[1]; Nelson, Ronald Owen ^[1]; Sefkow, Adam ^[2]; Shimada, Tsutomu ^[1]; Johnson, Randall Philip ^[1]; Fernandez, Juan Carlos ^[1]

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1. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2. Univ. of Rochester, NY (United States)

Images of the R2DTO resolution target were obtained during laser-driven-radiography experiments performed at the TRIDENT laser facility, and analysis of these images using the Bayesian Inference Engine (BIE) determines a most probable full-width half maximum (FWHM) spot size of 78 μm. However, significant uncertainty prevails due to variation in the measured detector blur. Propagating this uncertainty in detector blur through the forward model results in an interval of probabilistic ambiguity spanning approximately 35-195 μm when the laser energy impinges on a thick (1 mm) tantalum target. In other phases of the experiment, laser energy is deposited on a thin (~100 nm) aluminum target placed 250 μm ahead of the tantalum converter. When the energetic electron beam is generated in this manner, upstream from the bremsstrahlung converter, the inferred spot size shifts to a range of much larger values, approximately 270-600 μm FWHM. This report discusses methods applied to obtain these intervals as well as concepts necessary for interpreting the result within a context of probabilistic quantitative inference.

• Research Organization: Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA)
• DOE Contract Number: AC52-06NA25396
• OSTI ID: 1402669
• Report Number(s): LA-UR-17-28604
• Country of Publication: United States
• Language: English

Related Subjects

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radiography
laser-driven radiography
uncertainty