A high-speed radiation imaging system based on liquid scintillator filled capillary arrays

A high-speed radiation imaging system based on an image converter of liquid scintillator filled capillary arrays has been developed, which is sensitive to x rays, gamma rays, and neutrons. This imaging system has advantages of both high spatial resolution and high sensitivity because increasing the thickness of the image converter only leads to little deterioration on imaging resolution. The capillary arrays have dimensions of 150 mm diameter and 50 mm thickness, with 100 µm diameter of each capillary. The fluorescence decay time of the filled liquid scintillator based on the mixture of p-xylene and 2,5-diphenyloxazole has been evaluated to be ∼3 ns with the single photon method under the gamma ray excitation. The spatial resolution has been experimentally evaluated to be about 1.15 and 0.6 mm, under excitation of x rays and neutrons, respectively. The imaging system has been applied for diagnosing the dynamic x-ray spot generated by the rod pinch. Two frames in single shot with 15 ns temporal resolution and 20 ns inter-frame separation time have been obtained, which show the spatiotemporal distribution of the electrons bombarding the tungsten rod, indicating the ability of this imaging system in diagnosing dynamic radiation objects. In addition, the technique of capillary arrays provides a promising path for applications of advanced liquid scintillators in the field of radiation imaging.

Investigation of an InP-based image converter with optical excitation

An image converter based on an indium phosphide has been developed to measure the two-dimensional spatial profile of the incident photon flux by probing the rapid change of the refractive index in the semiconductor. The spatial resolution, dynamic range, and temporal response of this image converter have been investigated with optical methods. The results show that the spatial resolution is ∼15 cycles/mm at the percent modulation transfer function of 0.5, the dynamic range is about 100, and the time response is in the order of 600 ps. This scheme can provide an alternative choice as an imaging diagnostic for experiments in the area of high-energy density physics.