He jishu (Mar 2022)

Quality assurance and quality control of neutron activation analysis for determination of elements in lunar soil samples returned by Chang'E-5 mission

  • JIN Xiangchun,
  • XIAO Caijin,
  • YAO Yonggang,
  • ZHANG Junxin,
  • WU Peng,
  • WANG Pingsheng,
  • NI Bangfa

DOI
https://doi.org/10.11889/j.0253-3219.2022.hjs.45.030201
Journal volume & issue
Vol. 45, no. 3
pp. 030201 – 030201

Abstract

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BackgroundDetermination of the elements in lunar soil samples returned by Chang'E 5- mission is of great significance for exploring the origin of lunar soil and the physical and chemical conditions for its formation, and for studying the evolutionary history of the moon. Neutron activation analysis (NAA) has the inherent advantages of non-destructiveness, high sensitivity, and the ability to analyze multiple elements. The NAA Laboratory of China Institute of Atomic Energy (CIAE) is responsible for the quantitative analysis of elements in the lunar soil samples returned by Chang'E-5 mission.PurposeThis study aims at the quality assurance and the control of NAA for the determination of element content of lunar soil samples to ensure the accuracy and reliability of the analysis results.MethodsBased on the principle of neutron activation analysis and sources of error, the quality assurance measures taken by NAA laboratory in sample preparation, selection of analysis protocols, γ-ray spectrometer performance control, measurement, spectrum analysis, calibration were discussed. The results of NAA were evaluated and verified by internal quality control samples with known property values (and uncertainties) and the consistent in different characteristics γ rays of the same radionuclide. The analysis results of each element to be measured were compared with relative method and single comparator k0 method to achieve the purpose of internal quality control.ResultsThe analysis results of internal quality control samples meet the laboratory's acceptance criteria. Internal quality control methods such as repeated tests, etc., verify the consistency of the element measurement results.ConclusionsBy analyzing the measurement data, the reliability of the test results is verified, and the quality assurance process and quality control method are proved to be effective.

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