STP1102

    HPGe Gamma Spectroscopy Measurement of Natural Radionuclides in Water with a Focus on Current Hardware and Software Technologies

    Published: Jan 1991


      Format Pages Price  
    PDF Version (684K) 28 $25   ADD TO CART
    Complete Source PDF (9.4M) 28 $76   ADD TO CART


    Abstract

    High-resolution gamma spectroscopy provides fast, accurate, non-destructive isotopic analysis of natural radionuclides in environmental samples. Larger-volume, high-purity germanium detectors with relative efficiencies over 100% and less than 2.0 keV FWHM resolution for the 1332- keV peak of 60Co provide improved peak-to-background performance, which translates directly into either better sensitivity in constant counting time or better throughput for a given sensitivity. Short length-to-diameter coaxial detectors also provide improved resolution and lower noise than planar geometries. These short coaxial detectors also provide benefits for unfolding multiple peak features at lower energies, including the 226Ra and 235U interference at 185 keV and excellent sensitivity for low-energy X and gamma rays. Modern analyzers that provide 16000 channels of data memory allow system conversion gains from 200 to 250 eV/channel to be used with large coaxial detectors which cover a working energy range from 3.2 to 4.0 MeV, respectively. Analytical software is capable of unfolding the most difficult multiplet region with about 10% accuracy and other regions with even smaller uncertainty. Results of deconvolution tests are presented. Practical considerations regarding the measurement of water using this technique are presented, including recommended peaks, spectral interferences, background interference, calibration considerations, photon attenuation, and equilibrium conditions.

    Keywords:

    Gamma spectroscopy, gamma ray, uranium, thorium, actinide, environmental analysis, water


    Author Information:

    Seymour, RS
    research scientists, EG&G Instruments, Nuclear Products, Oak Ridge, TN

    Cox, JE
    research scientists, EG&G Instruments, Nuclear Products, Oak Ridge, TN


    Paper ID: STP17291S

    Committee/Subcommittee: D19.04

    DOI: 10.1520/STP17291S


    CrossRef ASTM International is a member of CrossRef.