Design of a five-layers multi-energy X-ray imaging detector for material sorting.

X-ray transmission imaging (XRT) is widely used for sorting materials. However, conventional single-energy and dual-energy X-ray systems have poor ability to discriminate between materials with similar atomic number (Z), and the count rate of available multi-energy XRT detectors could not support high-speed industrial applications. This paper presents the design of a detector that can potentiality achieve high-speed multi-energy X-ray imaging using Geant4 simulations.

A full spectral analysis method for the gamma spectrum: weighted library least squares.

The traditional library least squares approach (LLS) is affected by the inconsistency of the statistical uncertainties of different channels in a gamma spectrum, which leads to large fluctuations in the analysis results. This work proposes a weighted library least squares approach (WLLS) that uses the square root of the count to weight the regression objective function and has implemented a verification experiment based on Prompt Gamma Neutron Activation Analysis (PGNAA). The results showed that, after weighing using the square root of the count, the fluctuation level of statistical uncertainty in the spectrum was reduced from 44.

Research on the NIQAS device for hazardous goods identification based on PGNAA technology.

In the research, the Nuclide Identification and Quantitative Analysis System (NIQAS) for the identification of hazardous goods was designed and optimized by MCNP simulations. With the D-T neutron generator and HPGe detector set as the core of device, the modules, including reflector, moderator and shielding, etc., were optimized by a Signal-to-Noise Ratio (SNR) evaluation method.

[Study on Simultaneous Mercury and Lead Detection in Water Samples with PGNAA-XRF].

Prompt gamma neutron activation analysis (PGNAA) technology is used in heavy metals measurement. It is found that the detection accuracy of lead (Pb) is impacted heavily by mercury (Hg), because of thermal neutron cross section of mercury is much bigger than lead. In this paper, a new combined detection method was proposed to improve the lead measurement accuracy in situ environmental water rejects analysis by PGNAA-XRF.

Heavy metals detection in sediments using PGNAA method.

A prompt gamma ray neutron activation analysis detection system was developed to detect the heavy metals in sediments by using an (241)Am-Be neutron source and BGO detector. The samples containing cadmium and mercury were used to test the performance of setup. The linear relationship between prompt gamma ray counts and the concentrations was studied.

Online X-ray Fluorescence (XRF) Analysis of Heavy Metals in Pulverized Coal on a Conveyor Belt.

Heavy metals in haze episode will continue to threaten the quality of public health around the world. In order to decrease the emission of heavy metals produced from coal burning, an online X-ray fluorescence (XRF) analyzer system, consisting of an XRF analyzer with data acquisition software and a laser rangefinder, was developed to carry out the measurement of heavy metals in pulverized coal. The XRF analyzer was mounted on a sled, which can effectively smooth the surface of pulverized coal and reduce the impact of surface roughness during online measurement.

[New methodology for heavy metals measurement in water samples by PGNAA-XRF].

In the present paper, a new combined detection method was proposed using prompt gamma neutron activation analysis (PGNAA) and characteristic X-ray fluorescence to improve the heavy metals measurement accuracy for in-situ environmental water rejects analysis by PGNAA technology. Especially, the characteristic X-ray fluorescence (XRF) of heavy metals is induced by prompt gamma-ray directly instead of the traditional excitation sources. Thus, a combined measurement facility with an 241 AmBe neutron source, a BGO detector and a NaI-Be detector was developed to analyze the pollutants in water.