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The Kirkpatrick–Baez (KB) microscope is an effective instrument for x-ray imaging of hot spot. However, the non-uniform distribution of response efficiency in the field of view is a drawback of the KB microscope. A more accurate hot spot image requires the correction of the measured image by combining the hot spot position and the response efficiency distribution. Here, we describe a method to locate the position of the hot spot in the field of view during hot spot imaging with a KB microscope. The position of the hot spot in the field of view can be obtained by measuring the grazing incidence angle change during hot spot imaging. In the experiment of hot spot self-emission imaging with a four-channel KB microscope, the location of the hot spot with an accuracy of 15 μm was realized, and the intensity corrected hot spot image was obtained. This will solve the problem of the non-uniform distribution of the response efficiency of the KB microscope and enable quantitative measurement of hot spot radiation intensity.

Diagnosing the layered cryogenic DT implosions with traditional absorption based x-ray backlight radiography in inertial confinement fusion is a challenge because of the low opacity of the cold fuel. Refraction enhanced x-ray phase-contrast imaging was proposed for diagnosing optically opaque material. In this paper, A Monte Carlo tool based on Geant4 is employed to model the x-ray phase-contrast imaging for diagnosing cold fuel layer in cryogenic implosions. This model can successfully explain the x-ray phase-contrast imaging experimental results on a micro focus x-ray tube with triple-layer ablator capsules. Furthermore, the radiographs of ignition-scale capsule target is calculated. The fuel layer of DT ice can be observed with the phase contrast imaging and the image is faded using absorption imaging only. Our simulations show that the shape of cold fuel and implosion velocity can be inferred directly with the phase contrast imaging in inertial confinement fusion(ICF).

Two neutron time-of-flight (nToF) detectors have been employed to measure the neutron time-of-flight spectrum in different lines-of-sight, i.e., at the equator plane and the south pole, on Shenguang-III (SG-III) laser facility. The contribution of scattered neutrons has been calculated with the Monte Carlo code JMCT for each nToF detector. The results show that the scattered neutron spectrum is dominated by neutrons scattered on materials in the experiment hall, including the vacuum chamber. The shape of the scattered neutron spectrum depends on the view line, which has been observed with nToF detectors located in the experiment hall of the SG-III laser facility. A method based on the convolution of the calculated neutron time-of-flight spectrum and the instrument response function has been developed for the ion temperature determination. The calculated neutron spectra with the contribution of scattered neutrons can fit the measured results. No obvious ion temperature anisotropy has been observed on the SG-III laser facility at present.