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The Chang'E-5 (CE-5) lunar samples were analyzed nondestructively for more than 40 elements by instrumental neutron activation analysis (INAA) with a strict quality assurance and quality control. Based on the INAA results, some new observations and discoveries were made. Major, minor, and trace elements in CE-5 are very different from those of the Earth and Apollo lunar samples. The rare earth element (REE) pattern indicated that the CE-5 lunar samples are mare basalts with a clear negative anomaly in Eu. Element correlations are a very interesting discovery; for example, the ratios of Ba/La and FeO/MnO in CE-5 are almost identical to those of the Apollo lunar samples. These observations and discoveries will enrich the understanding of the formation and evolution of the Moon.

Forty-five years after the Apollo and Luna missions returned lunar samples, China's Chang’E-5 (CE-5) mission collected new samples from the mid-latitude region in the northeastern Oceanus Procellarum of the Moon. Our study shows that 95% of CE-5 lunar soil sizes are found to be within the range of 1.40–9.35 μm, while 95% of the soils by mass are within the size range of 4.84–432.27 μm. The bulk density, true density and specific surface area of CE-5 soils are 1.2387 g/cm3, 3.1952 g/cm3 and 0.56 m2/g, respectively. Fragments from the CE-5 regolith are classified into igneous clasts (mostly basalt), agglutinate and glass. A few breccias were also found. The minerals and compositions of CE-5 soils are consistent with mare basalts and can be classified as low-Ti/low-Al/low-K type with lower rare-earth-element contents than materials rich in potassium, rare earth element and phosphorus. CE-5 soils have high FeO and low Mg index, which could represent a new class of basalt.

Samples collected from February 2017 to January 2018 were analyzed by Particle Induced X-ray Emission (PIXE) and Black Carbon meter, and 17 elements were determined. Among them, S, Cl, K, Mn and BC had similar temporal trends with PM2.5, and increased significantly under heavy pollution in winter, while Al、Ca、Mg、Si and Ti were the typical crustal elements. From December 19th to 30th, seven samples were re-measured by short-irradiation of Neutron Activation Analysis (NAA), which performed 15 element concentrations, Ba, Ti, I, Br, Mn, Mg, Cu, In, Na, V, K, Cl, Al, Ca and S. In, Br, V, Ba and I increased remarkably in this process of pollution, compared with those not determined by PIXE. Moreover, NAA has a high sensitivity for In, a trace element in PM2.5,which may be a key element associated with potential pollution sources. For the common elements measured by NAA and PIXE, the values of Mn, Ca, Al, S and Mg were almost equal to each other.

The concentrations of PM2.5, black carbon (BC), elements as well as sources of pollution in Beijing from 2003 to 2018 were investigated. The results show that the concentrations of PM2.5 and BC had similar annual and seasonal trends, especially in autumn-winter, which with declining trends in recent years. The proportion of BC in PM2.5 reduced from 13% in 2013(max) to 8.5% in 2018(min), indicating the reducing measure of replacing coal boiler with gas boilers worked well. In this study, annual trends of 15 elements were also discussed, it is found that the concentrations of S, K, Mn, Ca, Pb, Cu, Mn and Fe displayed remarkable decrease these years. Br, Zn and Cl was growing overall and Cl was more concentrated in PM2.5 in autumn and winter. Moreover, the In detected by NAA with high sensitivity may be a new and crucial fingerprint element associated with coal combustion, industry emission or biomass combustion because of correlation with BC, Na, K, Cu and halogen elements well. Finally, 6-factor solution was identified during 2007 and 2016-2017 by EPA PMF, and the proportions of some pollution sources changed a lot in PM2.5. Soil management in north China reduced the soil and dust source by 9.2%; The contribution of Industry-S or secondary S showed decrease from 27.5% to 22.5% due to industries relocating , gasoline with sulfur optimization and coal burning restriction; Banning straw burning and waste incineration in 2007 kept biomass and waste combustion out gradually. However, initial stage of some policies maybe the main reasons for a small increase of coal combustion source despite some steps taken.

This work is based on the method of Monte Carlo simulation and probabilistic inversion for neutron depth profiling. The depth and concentration distribution of boron in a silicon matrix material is calculated. According to NDP experimental configuration at CARR, the energy spectra of a standard sample (SRM2137) are measured and simulated using MCNP and Geant4 software, and the concentration-depth profile of boron in SRM2137 is obtained by adopting an inverse iteration method through MATLAB software. It is shown that the inverse iteration calculation for NDP is feasible.

Delayed neutron counting (DNC) was applied in quantitative determination of 235U/238U, quantitative determination of 235U and 239Pu in 235U–239Pu co-existing samples at China Institute of Atomic Energy (CIAE). In this work, natural uranium, enriched uranium and their mixtures were used in the determinations of 235U/238U ratios. The results indicated that delayed neuron counting combined with neutron activation analysis(NAA) and k0-NAA for the measurement of gamma rays emitted by 239U decay is suitable for fast determination 235U/238U ratio. In addition, the contents of 235U and 239Pu in 235U–239Pu co-existing samples can also be determined respectively.

An integrated automation system of routine instrumental neutron activation analysis (INAA) with three HPGe detectors has been built at China Institute of Atomic Energy. This system is mainly composed of sample counting system, pneumatic transfer system, software control and analysis systems, etc. The characteristics include more than 200 samples can be controlled for a batch of INAA with three detectors simultaneously, sample counting position can be optimized automatically according to the counting dead time, the real-time tracking and the high consistency between the spectrum and counting sample are possible to be realized through radio frequency identification tag.

Multielements, including some rare earth elements, have been determined by k 0-NAA in three types of ore reference materials from Australia Nuclear Science and Technology Organization. The samples were irradiated in China Mianyang Research Reactor. High purity iron wire and Zr foil were used to monitor the neutron spectrum parameters (f, φ th) at irradiation positions. Uranium fission interferences for Nd, Ce, La were determined and corrected for by Ik0 method. The effective interaction depth was employed to normalize efficiencies at different counting positions. The results are in good agreement with the values reported other laboratories.

In order to do source apportionment of PM2.5 and source trajectories, particle induced X-ray emission and energy disperse-X ray fluorescence were used to analyze chemical composition of samples. Five major sources have been identified by using positive matrix factorization. Source trajectories have been determined by conditional probability function and the potential source contribution function. Extreme events, such as sandstorms, have been identified and traced.

The long lived isotopes 59Ni and 63Ni can be used in many areas such as radioactive waste management, neutron dosimetry, cosmic radiation study, and so on. Based on the large accelerator and a big Q3D magnetic spectrometer, the measurement method for 59Ni and 63Ni is under development at the AMS facility at China Institute of Atomic Energy (CIAE). By using the ΔE-Q3D technique with the Q3D magnetic spectrometer, the isobaric interferences were greatly reduced in the measurements of 59Ni and 63Ni. A four anode gas ionization chamber was then used to further identify isobars. With these techniques, the abundance sensitivities of 59Ni and 63Ni measurements are determined as 59Ni/Ni = 1 × 10−13 and 63Ni/Ni = 2 × 10−12, respectively.

The analysis of elemental distribution in key parts of samples is of importance in the fields of material science. A non-invasive method utilizing neutrons has been presented. The elemental distribution of materials can be obtained by measuring the gamma spectra with collimated neutron beams using in-beam neutron activation analysis. In order to verify the feasibility of neutron imaging and activation analysis in elemental distribution studies, the experimental model was calculated and verified by Monte Carlo simulations. Using the CARR reactor neutron imaging and activation analysis system, the elemental distribution experiment of the flat sample was carried out. The neutron radiography results of the flat sample and the gamma spectrum of each measurement area were analyzed. The distribution of In, Gd, Eu, Au, and B were in good agreement with the sample. Neutron radiography and in-beam activation analysis were effective tools for conducting elemental distribution studies.

The facility for delayed neutron counting was built at the China Institute of Atomic Energy in the 1980s. A method of normalized decaying curve of delayed neutron is proposed in this work. Preliminary experiments show that this method is suitable for the determinations of uranium in samples with a wide range of uranium concentrations.

The search for dark matter (DM) is a hot field nowadays, a number of innovative techniques have emerged. The superheated droplet technique is relatively mature; however, it is recently revitalized in a number of frontier fields including the search for DM. In this work, the acoustic response of Superheated Droplet Detectors (SDDs) to neutrons was studied by using a 252Cf neutron source, SDDs developed by the China Institute of Atomic Energy, a sound sensor, a sound card and a PC. Sound signals were filtered. The characteristics of FFT spectra, power spectra and time constants were used to determine the authenticity of the bubbles analyzed.

Neutron bubble detector is so far the only personal neutron dosimeter satisfying the energy response criteria of the International Committee of Radiation Protection 60 (ICRP 60). This paper presents our studies on neutron bubble detectors including the manufacture, the relevant equipments, the basic calibrations and on-site tests for monitoring personal neutron dose. The results of calibrations show that the highest sensitivity so far manufactured by the authors reaches about 4bubbles/μSv, the correlation coefficient of dose response is 0.99, and the in-batch consistency and reproducibility are up to the ISO standards. The results of on-site test show that the in-batch consistency and between-batch consistency are within 15% relative standard uncertainty. The results are directly readable. The detectors are portable, especially suitable for on-site neutron dose monitoring in n-γ mixed radiation fields.

Taking advantages of nuclear analytical techniques (NATs) with non-destruction, multielement capability, small and estimable uncertainties over a wide range of sample sizes, the sampling behavior of multielements for a home-made natural matrix material was studied with sample sizes ranging from several hundred mg down to tenths ng, namely nine orders of magnitude, by a combination of three NATs, neutron activation analysis (NAA), proton induced X-ray emission (PIXE) and synchrotron radiation X-ray flurescence (SR-XRF), in an effort to explore a procedure for the development of certified reference materials (CRMs) suitable for quality control of microanalysis. For accurately weighable sample sizes (>1 mg), sampling uncertainties for 13 elements were found to be less than 1% by INAA. For sample sizes unable to be accurately weighed (

A total of 178 aerosol samples in two size fractions, PM10-2.5 (coarse) and PM2.5 (fine), were collected on nucleopore films using a Gent stacked filter unit sampler at the Graduate School of China Nuclear Industrial Group during May 2007 to November of 2009. Black carbon was determined by a reflectometer. A total of 16 elements, Mg, Al, S, Si, P, Cl, Ca, K, Ti, Mn, Fe, Ni, Cu, Zn, As and Pb, were determined by Particle Induced X-ray Emission. Mg, Al, Ca, K and Mn were also determined by Neutron Activation Analysis. Concentrations of all these elements were used to identify possible pollution sources and directions of the airborne particulate matter by means of softwares PMF and CPF. Some extraordinary events, such as sandstorms, firework and transboundary fire smoke were pinpointed by a combination of time series of multielement, relevant meteorological data and softwares Wind rose, Hysplit, and Google earth.

Twenty different brands of Chinese tea were analyzed for multiple trace elements, including some essential and toxic elements, by neutron activation analysis (NAA). A comparison among tea brands from China, India, US and other countries was made for the ranges and averages of concentrations for Na, K, Mn, Cu, and Br. It has been observed that the trace element contents in tea leaves are largely dependent upon the soil and the environment where the tea grows. Chinese tea is rich in Mn and Cu comparing with those of other counties surveyed, but is indigent in Na. The transference ratio for each element determined (i.e., the fraction of an element in tea leave transferred into solution when tea is leached by percolation) is also reported. Adult daily intakes of some essential and toxic elements from tea drinking were also estimated.

An expression of γ-ray efficiency for large samples is proposed based on numerical integration of efficiencies over compositional point sources. The widely used expression on radial variation of HPGe efficiency for point source originally proposed by Noguchi et al. (Int J Appl Radiat Isot 32:17–22, 1980 [1]) was amended and a new expression was proposed. A comparison between the two expressions indicates that the newly proposed expression brings about an obvious improvement, and Self-absorption correction for a voluminous source is also given out by using the EID principle. The functional relationship between HPGe efficiency for γ-rays from a point source and the spatial position of the source was established. The results of this study can be applied in order to determine γ attenuation effects of unknown bulky samples with various shapes and materials.