14–19 Jun 2026
Monterey, California (USA)
US/Pacific timezone
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Neutron and gamma-ray characterization of the ATHENA NIF energy tuning assembly

18 Jun 2026, 15:20
20m
Monterey, California (USA)

Monterey, California (USA)

Hilton Garden Inn Monterey
Oral Presentations Parallel

Speaker

Darren Bleuel (LLNL)

Description

A THermal Energy Neutron Assembly (ATHENA) is an experimental platform based at the National Ignition Facility (NIF) for performing neutron irradiation experiments. It consists of a cone-shaped assembly deployed as close as 6 cm from the NIF implosion, moderating the neutron flux from a pure 14 MeV DT spectrum to an analogue of a mixed fusion/fission spectrum for materials testing and integral benchmarks for nuclear data. This neutron spectrum has been modeled with neutronics codes like MCNP, but lacks comprehensive experimental verification. The photon spectrum created by neutron interactions in ATHENA is similarly ill-characterized and initial measurements with low-resolution monitors at the NIF have suggested a much higher induced photon flux than models predict.

To more accurately characterize both the moderated neutron and induced photon spectrum of ATHENA in response to DT fusion neutrons, measurements were conducted with a DT generator as the source. A number of detectors measured multiple aspects of the field in several locations, including deuterated organic scintillators, a high-purity germanium detector, a LaBr3 detector, and a suite of activation foils. Preliminary observations from each of these detectors will be presented.

Contribution category Experiment
Presenter status Faculty/Staff

Author

Darren Bleuel (LLNL)

Presentation materials

There are no materials yet.