Size Measurement of Radioactive Aerosol Particles in Intense Radiation Fields Using Wire Screens and Imaging Plates

  • Received : 2015.07.17
  • Accepted : 2016.09.24
  • Published : 2016.09.30


Background: Very fine radiation-induced aerosol particles are produced in intense radiation fields, such as high-intensity accelerator rooms and containment vessels such as those in the Fukushima Daiichi nuclear power plant (FDNPP). Size measurement of the aerosol particles is very important for understanding the behavior of radioactive aerosols released in the FDNPP accident and radiation safety in high-energy accelerators. Materials and Methods: A combined technique using wire screens and imaging plates was developed for size measurement of fine radioactive aerosol particles smaller than 100 nm in diameter. This technique was applied to the radiation field of a proton accelerator room, in which radioactive atoms produced in air during machine operation are incorporated into radiation-induced aerosol particles. The size of $^{11}C$-bearing aerosol particles was analyzed using the wire screen technique in distinction from other positron emitters in combination with a radioactive decay analysis. Results and Discussion: The size distribution for $^{11}C$-bearing aerosol particles was found to be ca. $70{\mu}m$ in geometric mean diameter. The size was similar to that for $^7Be$-bearing particles obtained by a Ge detector measurement, and was slightly larger than the number-based size distribution measured with a scanning mobility particle sizer. Conclusion: The particle size measuring method using wire screens and imaging plates was successfully applied to the fine aerosol particles produced in an intense radiation field of a proton accelerator. This technique is applicable to size measurement of radioactive aerosol particles produced in the intense radiation fields of radiation facilities.


Supported by : JSPS KAKENHI


  1. International Commission of Radiological Protection. Human respiratory tract model for radiological protection. ICRP Publication 66. 1994;24:106-114.
  2. Hinds WC. Aerosol technology: Properties, behavior, and measurement of airborne particles. 2nd Ed. New York NY. Wiley-Interscience. 1999;160-168.
  3. Cheng YS, Yeh HC, Theory of a screen-type diffusion battery. J. Aerosol Sci. 1980;11:313-320.
  4. Fukutsu K, Yamada Y, Tokonami S, Iida T. Newly designed graded screen array for particle size measurements of unattached radon decay products. Rev. Sci. Inst. 2004;75:783-787.
  5. Cunningham E. On the velocity of steady fall of spherical particles through fluid medium. Proc. R. Soc. 1910;A-83:357-365.
  6. Symon KR, Kerst DW, Jones LW, Laslett LJ, Terwilliger KM. Fixed-field alternating-gradient particle accelerators. Phys. Rev. 1956;103:1837-1859.
  7. Ishi Y, et al. Present status and future of FFAGs at KURRI and the first ADSR experiment. Proc. of International Particle Accelerator Conference (IPAC' 10). Kyoto Japan. May 23-28, 2010.
  8. Osada N, Oki Y, Yamasaki K, Shibata S. Influence of radioactive gas on particle size measurement of radioactive aerosol with diffusion battery method. Prog. Nucl. Sci. Tech. 2011; 1:483-486.
  9. Osada N, Oki Y, Kanda H, Yamasaki K, Shibata S, Application of a graded screen array for size measurements of radioactive aerosols in accelerator rooms. Proc. Radiochim. Acta. 2011;1:251-255.
  10. Muramatsu H, Kondo K, Kanda Y. Radioactive airborne species formed in the tunnels of a high energy accelerator tunnels. Appl. Radiat. Isot. 1988;39:413-419.
  11. Kondo K. Radioactive airborne species formed in the air in high energy accelerator tunnels. J. Nucl. Radiochem. Sci. 2006;7:R31-R36.
  12. Oki Y, Kondo K, Kanda Y, Miura T. Aerosol-Size Distribution of Radon Daughter 218Po in the Accelerator Tunnel Air. J. Radioanal. Nucl. Chem. 1999;239:501-505.
  13. Lassen L, Rau G. Die Anlagerung radioaktiver Atome an Aerosols (Schwebstoffe). Z. Phys. 1960;160:504-519.
  14. Endo A, Oki Y, Kanda Y, Oishi T, Kondo K. Evaluation of internal and external doses from ${11}^C$ produced in the air in high energy proton accelerator tunnels. Radiat. Prot. Dosim. 2001;93:223-230.
  15. Kaneyasu N, Ohashi H, Suzuki F, Okuda T, Ikemori F. Sulfate aerosol as a potential transport medium of radiocesium from the Fukushima nuclear accident. Environ. Sci. Technol. 2012;46:5720-5726.
  16. Kondo K, Muramatsu H, Kanda Y, Takahara S. Particle size distribution of 7Be-aerosols formed in high energy accelerator tunnels. Int. J. Appl. Radiat. Isot. 1984;35:939-944.