Fast neutron radiography (FNR) using divergent neutron beams has the characteristic to magnify small cracks in low-Z materials. For such magnifying FNR systems, a simple method was developed using Monte Carlo simulations to estimate the spatial resolution. The resolution degrading factors, including neutron source size, object thickness, and crosstalk in the detector, have been investigated in this method. The calculated results of this method compare favorably to independent estimations of various designs for the same FNR system. For a magnifying FNR system, a better spatial resolution can be expected with larger magnifications and smaller sources.

Deuterium–tritium neutron yield has reached up to about 1013 at the 100 kJ-level laser facility, which makes measurement of neutron emission images possible with the neutron imaging system. There are two methods to collect neutron images from the scintillator array, optical fiber taper and the lens system. Here, we report a design of the lens system for the neutron imaging system at the 100 kJ-level laser facility. The lens system, which consists of a nine-element collecting lens, with a spatial resolution of 20 µm and a light-collection efficiency of 5.9% has been designed.

Neutron/x-ray combined radiography can integrate the merits of x-ray and neutron radiography and have an enhanced non-destructive detecting capability compared to single neutron or x-ray radiography. In this work, magnifying neutron/x-ray combined radiography along the same line of sight was performed at the Shenguang (SG) laser facility for the first time. Based on [Formula: see text] mm point-like backlight sources of neutrons and x rays, structural defects on the order of ∼0.2 mm within polyethylene and Fe were observed in neutron and x-ray radiography, respectively. In addition, the spatial resolution obtained was 0.68 ∼ 2.05 mm in the object position for neutron radiography and ∼0.14 mm for x-ray radiography. This indicated that the combined radiography system arranged along the same line of sight at the SG laser facility possessed the ability to inspect structural defects within both low-Z and high-Z materials simultaneously, with relatively high spatial resolution.

To achieve ignition in a laboratory via inertial confinement fusion, a spherical capsule containing a frozen layer of deuterium and tritium (DT) fuel will be imploded on an MJ-class laser facility. However, if pure deuterium fuel can be used in place of DT fuel for tuning shots, we may speed up the process of ignition experiments while maintaining the surrogacy by significantly reducing the level of radioactivity. Unfortunately, it has long been assumed that neither the approach of symmetrical infrared irradiation used in the Omega direct-drive experiments nor the method of beta-layering used in the NIF experiments can be used to smooth the D layered capsule in cylindrical hohlraums. The difficulty in smoothing the D ice layer prevents us from taking advantage of cryogenic D-layered capsules in indirect-drive experiments. In this work, we established a procedure to form a uniform D-ice layer for capsules held in cylindrical hohlraums and carried out indirect-drive cryogenic D-layered implosion experiments using a squared laser pulse on the Shenguang laser facility in China. The quality of the D ice layer is characterized by phase-contrast imaging. The root-mean-square of the power spectrum in modes 2-100 is about 2.2μm. The implosion performance of the D-layered capsules is close to the prediction of one-dimensional simulations. The measured neutron yield and areal fuel density are 1.2×1011 and 80mg/cm2, respectively.