Modeling study of a proposed field calibration source using K-40 and high-Z targets for sodium iodide detectors
- Remote Sensing Lab. (United States)
- Texas A & M Univ., College Station, TX (United States)
- Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
Calibration sources based on the primordial isotope potassium-40 (40K) have reduced controls on the source’s activity due to its terrestrial ubiquity and very low specific activity. Potassium–40’s beta emissions and 1,460.8 keV gamma ray can be used to induce K-shell fluorescence x rays in high-Z metals between 60 and 80 keV. A gamma ray calibration source that uses potassium chloride salt and a high-Z metal to create a two-point calibration for a sodium iodide field gamma spectroscopy instrument is thus proposed. The calibration source was designed in collaboration with the Sandia National Laboratory using the Monte Carlo N-Particle eXtended (MCNPX) transport code. Two methods of x-ray production were explored. First, a thin high-Z layer (HZL) was interposed between the detector and the potassium chloride-urethane source matrix. Second, bismuth metal powder was homogeneously mixed with a urethane binding agent to form a potassium chloride-bismuth matrix (KBM). The bismuth-based source was selected as the development model because it is inexpensive, nontoxic, and outperforms the high-Z layer method in simulation. As a result, based on the MCNPX studies, sealing a mixture of bismuth powder and potassium chloride into a thin plastic case could provide a light, inexpensive field calibration source.
- Research Organization:
- Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
- Sponsoring Organization:
- USDOE National Nuclear Security Administration (NNSA)
- Grant/Contract Number:
- AC04-94AL85000
- OSTI ID:
- 1333863
- Report Number(s):
- SAND-2015-2204J; 579556
- Journal Information:
- Health Physics, Vol. 110, Issue 6; ISSN 0017-9078
- Publisher:
- Health Physics SocietyCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Similar Records
Neutron detection and multiplicity counting using a boron-loaded plastic scintillator/bismuth germanate phoswich detector array
Bi-Modal Model for Neutron Emissions from PuO{sub 2} and MOX Holdup