Collinear neutron imaging and multiplexed time-of-flight spectroscopy of spherical implosions on OMEGA

Neutron imaging of inertial confinement fusion (ICF) implosions measures the spatial distribution of the thermonuclear hotspot and is robustly implemented at the National Ignition Facility (NIF) within the nuclear imaging systems (NIS). With the advent of repeatable ignition on the NIF, high yield capabilities are being designed to explore new physics in these implosions, including the spatially resolved ion temperature distribution. A 1D proof-of-concept [1] has been successfully demonstrated on the OMEGA laser facility, and a full 2D system is being explored for ignition-class shots on the NIF. A quasi-2D proof-of-concept is also being designed for demonstration at sub-ignition yields – the current design would require temporally multiplexed neutron time-of-flight (nTOF) measurements [2] to be performed collinear with an extended neutron aperture. Recent experiments at the OMEGA laser facility demonstrated neutron imaging collinear with a 3-fiber time-multiplexed nTOF system. Results are compared against a collinear fixed OMEGA nTOF detector to validate the technique and against MCNP [3] simulations to examine the spectral contribution of the aperture.



[1] C. Danly, et al., RSI 94, 043502 (2023).

[2] L. Tafoya, et al., Rev. Sci. Instr. 95, 093512 (2024).

[3] J. Kulesza, et al., MCNP Code 6.3 Manual (2022).



This work was supported by the NSF GRFP under Grant No. DGE 2241144 and the NNSA under the US DOE by Cooperative Agreement No. DE-NA0004148 and LANL under Contract No. 89233218CNA000001.