Neutron imaging of the deuterium-tritium tamping gas volume in an inertial confinement fusion hohlraum

N Izumi; D P Higginson; M D Rosen; W M Riedel; B M Haines; D N Fittinghoff; P Volegov; A E Youmans; A Kemp; T Chapman; C Hardy; J Gjemso; C Waltz; S M Rogers; B N Woodworth; T Sarginson; R Cheung; N Masters; R Sandoval; T Cunningham; R Ramirez; J P Holder; R L Reynolds; D M Holunga; T M Briggs; S Vonhof; N T Roskopf; D Schlossberg; A S Moore; S Kerr; K D Hahn; B L Reichelt; A J Mackinnon; J D Moody; J S Ross; D Hinkel

doi:10.1063/5.0219564

Neutron imaging of the deuterium-tritium tamping gas volume in an inertial confinement fusion hohlraum

Rev Sci Instrum. 2024 Oct 1;95(10):103510. doi: 10.1063/5.0219564.

Authors

N Izumi¹, D P Higginson¹, M D Rosen¹, W M Riedel¹, B M Haines², D N Fittinghoff¹, P Volegov¹, A E Youmans¹, A Kemp¹, T Chapman¹, C Hardy¹, J Gjemso¹, C Waltz¹, S M Rogers¹, B N Woodworth¹, T Sarginson¹, R Cheung¹, N Masters¹, R Sandoval¹, T Cunningham¹, R Ramirez¹, J P Holder¹, R L Reynolds¹, D M Holunga¹, T M Briggs¹, S Vonhof³, N T Roskopf¹, D Schlossberg¹, A S Moore¹, S Kerr¹, K D Hahn¹, B L Reichelt⁴, A J Mackinnon¹, J D Moody¹, J S Ross¹, D Hinkel¹

Affiliations

¹ Lawrence Livermore National Laboratory, Livermore, California 94550, USA.
² Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
³ General Atomics, La Jolla, California 92121, USA.
⁴ Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.

PMID: 39365111
DOI: 10.1063/5.0219564

Abstract

To benchmark the accuracy of the models and improve the predictive capability of future experiments, the National Ignition Facility requires measurements of the physical conditions inside inertial confinement fusion hohlraums. The ion temperature and bulk motion velocity of the gas-filled regions of the hohlraum can be obtained by replacing the helium tamping gas in the hohlraum with deuterium-tritium (DT) gas and measuring the Doppler broadening and Doppler shift of the neutron spectrum produced by nuclear reactions in the hohlraum. To understand the spatial distribution of the neutron production inside the hohlraum, we have developed a new penumbral neutron imager with a 12 mm diameter field of view using a simple tungsten alloy spindle. We performed the first experiment using this imager on a DT gas-filled hohlraum and successfully obtained the spatial distribution of neutron production in the hohlraum plasma. We will report on the design of the spindle, characterization of the detectors, and methodology of the image reconstruction.