Instrumental Neutron Activation Analysis of Chang’E-5 Lunar Regolith Samples

Abstract

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.

Bulk compositions of the Chang’E-5 lunar soil: Insights into chemical homogeneity, exotic addition, and origin of landing site basalts

“…Whether or not these processes affected the compositions of the CE-5 soil is not currently clear. The extent to which their compositions differ from returned Apollo and Luna samples are not well understood , Yao et al 2022. High concentrations of volatiles and heat-producing elements like K, U, and Th that are mainly distributed in the KREEP, a material characterized by K, rare earth elements, and P-rich, in the mantle source are expected to have sustained young mare magmatism in the Northern Oceanus Procellarum (Laneuville et al, 2018).…”

Determination Of The Multi-Elemental Composition Of Lunar Meteorites Using Instrumental Neutron Activation Analysis

“…The elements (Na, Al, and Mg) with neighboring atomic numbers can yield similar nuclides via fast neutron threshold reactions, such as (n, p) and (n, α). 9 In the present study, the fast neutron fluence rate was obtained through 54 Fe (n, p) 54 Mn nuclear reaction. The fast-neutron-induced reaction interferences were estimated for all relevant elements, and interference corrections were performed.…”

“…This permits a more comprehensive modeling of the origins and distribution of these lunar materials. According The Cl-chondrite-normalized 34 REE patterns for NWA 4734, NWA 11111, Apollo, 32,35 and CE-5 9 samples are shown in Fig. 1.…”

“…In addition to the large range of meteorite compositions, a variety of compositional parameters distinguishes lunar meteorites from terrestrial materials. 11 Nondestructive or non-invasive analytical techniques, such as electron probe microanalysis (EPMA), 12,13 X-ray fluorescence (XRF) analysis, 14 laser-induced breakdown spectroscopy (LIBS), 14 and instrumental neutron activation analysis (INAA), 9,15,16 are increasingly used for analyzing the elemental composition of rare and precious lunar materials. INAA is a sensitive radioanalytical method based on measuring characteristic radiation from radionuclides formed by irradiating samples with neutrons.…”

“…Therefore, it is an ideal technique to determine most of the constituents in precious lunar and meteorite samples. 19,20 Because of the advantages of INAA, the Apollo 17 sample, 21 which was a national gift from the United States to China in 1978, and the first lunar sample acquired by China through the CE-5 mission 4,9 was analyzed using the INAA method.…”