| Autor: |
Rogers J; National Security Technologies, Remote Sensing Laboratory, PO Box 89521, Las Vegas, NV; †Nuclear Security Science and Policy Institute, Texas A&M University, 3473 TAMU, College Station, TX; ‡Sandia National Laboratory, PO Box 5800 MS0671, Albuquerque, NM; §Department of Nuclear Engineering, Texas A&M University, 3473 TAMU, College Station, TX., Marianno C, Kallenbach G, Trevino J |
| Jazyk: |
angličtina |
| Zdroj: |
Health physics [Health Phys] 2016 Jun; Vol. 110 (6), pp. 563-70. |
| DOI: |
10.1097/HP.0000000000000504 |
| Abstrakt: |
Calibration sources based on the primordial isotope potassium-40 (K) 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. 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. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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