Dangerous materials inspection is an important technique to confirm dangerous materials crimes. It has significant impact on the prohibition of dangerous materials-related crimes and the spread of dangerous materials. Lobster-Eye Optical Imaging System is a kind of dangerous materials detection device which mainly takes advantage of backscatter X-ray. The strength of the system is its applicability to access only one side of an object, and to detect dangerous materials without disturbing the surroundings of the target material.
The device uses Compton scattered x-rays to create computerized outlines of suspected objects during security detection process. Due to the grid structure of the bionic object glass, which imitate the eye of a lobster, grids contribute to the main image noise during the imaging process. At the same time, when used to inspect structured or dense materials, the image is plagued by superposition artifacts and limited by attenuation and noise. With the goal of achieving high quality images which could be used for dangerous materials detection and further analysis, we developed effective image process methods applied to the system. The first aspect of the image process is the denoising and enhancing edge contrast process, during the process, we apply deconvolution algorithm to remove the grids and other noises. After image processing, we achieve high signal-to-noise ratio image. The second part is to reconstruct image from low dose X-ray exposure condition. We developed a kind of interpolation method to achieve the goal. The last aspect is the region of interest (ROI) extraction process, which could be used to help identifying dangerous materials mixed with complex backgrounds. The methods demonstrated in the paper have the potential to improve the sensitivity and quality of x-ray backscatter system imaging.
In order to counter drug-related crimes effectively, and to safeguard homeland security as well as public safety, it is important to inspect drugs, explosives and other contraband quickly and accurately from the express mail system, luggage, vehicles and other objects.
In this paper, we discuss X-ray backscatter inspection system based on a novel lobster-eye X-ray objective, which is an effective inspection technology for drugs, explosives and other contraband inspection. Low atomic number materials, such as drugs and explosives, leads to strong Compton scattering after irradiated by X-ray, which is much stronger than high atomic number material, such as common metals, etc. By detecting the intensity of scattering signals, it is possible to distinguish between organics and inorganics. The lobster-eye X-ray optical system imitates the reflective eyes of lobsters, which field of view can be made as large as desired and it is practical to achieve spatial resolution of several millimeters for finite distance detection. A novel lobster-eye X-ray objective is designed based on modifying Schmidt geometry by using multi-lens structure, so as to reduce the difference of resolution between the horizontal and vertical directions. The demonstration experiments of X-ray backscattering imaging were carried out. A suitcase, a wooden box and a tire with several typical samples hidden in them were imaged by the X-ray backscattering inspection system based on a lobster-eye X-ray objective. The results show that this X-ray backscattering inspection system can get a resolution of less than five millimeters under the FOV of more than two hundred millimeters with ~0.5 meter object distance, which can still be improved.
X-ray imaging of the laser produced plasma plays an important role in plasma diagnostics. Based on the urgent needs of
conducting deeper and finer physical experiments, we developed a high-energy Kirkpatrick Baez microscope working at
17.48keV with a spectral resolution (E/▵E) of ~30. The concave spherical substrates was polished, ultrasonically cleaned
and coated. The substrates have a radius of curvature of 20m with a roughness better than 0.3nm. The grazing incidence
angles are designed at 0.7° and 0.73° for separate reflecting mirrors. The x-ray backlit imaging experiments show its
spatial resolution is ~5.5μm at best focus. The effective field of view is measured to be ~90μm, which is consistent with
the multilayer design. This article provides detailed informations for the optical design, multilayers coating and
characterization of the microscope. The microscope promises to be a high-energy, high-resolution, and energy resolved
X-ray diagnostics instrument for SG series laser facility.
In the field of target diagnostics for Initial Confinement Fusion experiment, high resolution X-ray imaging system is
seriously necessary to record the evolution details of target ablation-front disturbance at different energy points of backlight
conditions. Kirkpatrick-Baez mirror is a wide used imaging system to achieve a large efficient field of view with high
spatial resolution and energy transmitting capability. In this paper, we designed a novel type of reflective microscope based
on Kirkpatrick-Baez structure, and this system can achieve 5μm spatial resolution at 600μm field of view specific energy
point in one dimension.