Vol. 6, 2021

Radiation Measurements

EVALUATION OF ENVIRONMENTAL NEUTRON DOSE AT GROUND LEVEL

N. Marchese, A. Parlato, E.A.G. Tomarchio

Pages: 48-51

DOI: 10.37392/RapProc.2021.10

This work presents the results of two cycles of neutron dose rate measurements realized using an ALNOR 2202D Neutron Dose Rate Meter whose time response is acquired and analyzed through a controlled ORTEC MCS-32 acquisition card in Windows environment. The data obtained have been compared with values from previous experimental surveys and with the data provided by the worldwide main observatories. It has been also verified the influence of the fluctuations in the flux of cosmic rays during the course of a solar cycle. By comparing the realized measurements and the data provided by the cosmic ray monitoring networks it is also possible to obtain a value of ambient dose equivalent rate and neutron flux rate which can be used as a reference for design a neutron irradiation testing of electronic devices.
  1. F. Cannizzaro, G. Greco, M. Raneli, M. C. Spitale, E. Tomarchio, “Behaviour of 7Be Air Concentration observed during a period of 13 years and Comparison with Sun Activity,” Nucl. Geophys., vol. 9, no. 6, pp. 597 – 607, 1995.
    DOI: 10.1016/0969-8086(95)00043-7
  2. F. Cannizzaro, G. Greco, M. Raneli, M. C. Spitale, E. Tomarchio, “Concentration measurements of 7Be at ground level air at Palermo, Italy – Comparison with solar activity over a period of 21 years,” J. Environ. Radioact., vol. 72, no. 3, pp. 259 – 271, 2004.
    DOI: 10.1016/S0265-931X(03)00177-2
    PMid: 14972409
  3. S. Basile, R. Burlon, E. Tomarchio, “Analysis of 7Be and 210Pb concentration and 7Be/210Pb activity ratio in ground level air at Palermo (Italy),” Radiat. Eff. Defects Solids, vol. 174, no. 11 – 12, pp. 998 – 1007, 2019.
    DOI: 10.1080/10420150.2019.1683838
  4. Neutron Monitor DataBase (NMDB), European Commission, Brussels, Belgium.
    Retrieved from: http://www01.nmdb.eu
    Retrieved on: Aug. 20, 2021
  5. Sunspot Index and Long-term Solar Observations (SILSO) , on-line Sunspot Number catalogue: years: 2012 and 2020, Royal Observatory of Belgium, Brussels, Belgium.
    Retrieved from: http://www.sidc.be/silso/
    Retrieved on: Aug. 20, 2021.
  6. T. Nunomiya, S. Abe, N. Hirabayashi, T. Nakamura, “Sequential Measurements of Cosmic-Ray Neutron Energy Spectrum and Ambient Dose Equivalent on the Ground,” J. Nucl. Sci. Technol., vol. 41, suppl. 4, pp. 466 – 469, Mar. 2004.
    DOI: 10.1080/00223131.2004.10875748
  7. T. Nakamura et al., “Sequential Measurements of Cosmic-Ray Neutron Energy Spectrum and Ambient Dose Equivalent on the Ground,” presented at the 11th Int. Conf. International Radiation Protection Association (IRPA 11) , Madrid, Spain, May 2004.
  8. T. Nakamura, T. Nunomiya, S. Abe, K. Terunuma, H. Suzuki, “Sequential Measurements of Cosmic-Ray Neutron Spectrum and Dose Rate at Sea Level in Sendai, Japan,” J. Nucl. Sci. Technol., vol. 42, no. 10, pp. 843 – 853, Oct. 2005.
    DOI: 10.1080/18811248.2005.9711035
  9. T. Nakamura, “Cosmic-ray Neutron Spectrometry and Dosimetry,” J. Nucl. Sci. Technol., vol. 45, suppl. 5, pp. 1 – 7, Jun. 2008.
    DOI: 10.1080/00223131.2008.10875772
  10. M. Kowatari et al., “Evaluation of Geomagnetic Latitude Dependence of the Cosmic-ray Induced Environmental Neutrons in Japan,” J. Nucl. Sci. Technol., vol. 44, no. 2, pp. 114 – 120, 2007.
    DOI: 10.1080/18811248.2007.9711264
  11. K. Lee, R. Sheu, “Comparing two Measurements of the same Cosmic-ray neutron spectrum using standard Bonner Spheres and high-sensitivity Bonner cylinders,” Radiat. Prot. Dosimetry, vol. 177, no. 4, pp. 450 – 457, Dec. 2017.
    DOI: 10.1093/rpd/ncx063
    PMid: 29272885
  12. D. A. H. Rasolonjatovo et al., “Measurement for the Dose-rates of the Cosmic-ray Components on the Ground,” J. Radiat. Res., vol. 43, no. Suppl, pp. S27 – S33, Dec. 2002.
    DOI: 10.1269/jrr.43.S27
    PMid: 12793726
  13. G. F. Krymsky, V. G. Grigor’ev, S. A. Starodubtsev, “New method for estimating the absolute flux and energy spectrum of solar cosmic rays based on neutron-monitor data,” JETP Lett., vol. 88, no. 7, pp. 411 – 413, Dec. 2008.
    DOI: 10.1134/S0021364008190016