Vol. 2, 2017

Radiation Measurements


N. Mirzajani, S. O. Souza, F. d’Errico

Pages: 59-63

DOI: 10.21175/RadProc.2017.13

The transport and interactions of gamma-rays in a thin film loaded with optically stimulated luminescence (OSL) nanoparticles (NPs) were studied by Monte Carlo (MC) simulations with the Particle and Heavy Ion Transport code System (PHITS). In the MC input file, the geometry of the thin film was treated as a virtual space using a cubic voxel structure with a lattice of nanoparticles (NPs) of OSL CaF2:Ce. The particles were monodispersed, ranging in size from 50 to 600 nm. The polyvinyl chloride (PVC) film matrix was treated as an array simulating a small sample with an area of 13.8 µm by 13.8 µm and a thickness of 10.2 µm. For the irradiation simulations, we considered a collimated beam of cesium-137 gamma-rays of 662 keV impinging perpendicularly on the piece of thin film (detector). The film was centered on the front face of 30 cm x 30 cm x 15 cm ISO water slab phantom. In the MC simulations, we followed the radiation tracks and calculated the energy deposition from the tracks of electrons produced by the interaction histories of the photons crossing the thin film. The energy deposition in the OSL film is initially fairly constant with grain size and then increases as the CaF2:Ce grains get larger to the point of filling 50% of the voxel volume. For grain sizes up to almost 400 nm, the presence of the grains has minimal impact, i.e., the dose is mainly deposited by secondary electrons generated within the polymer. This allows for the design of tissue-equivalent dosimeters even with embedded OSL materials, such as CaF2, that exhibit a higher Z-value than tissue.
  1. M. Pal et al., “Thermoluminescnce and Optically Stimulated Luminescence Properties of -Irradiated TiO2:Yb Nanoparticles,” J. Nanosci. Nanotechnol.,vol. 9,no. 3, pp. 1851 – 1857, Mar. 2009.
    DOI: 10.1166/jnn.2009.369
    PMid: 19435049
  2. V. S. M. Barros et al., “Thermoluminescent dosimetric properties of CaF2:Tm produced by combustion synthesis,” J. Radiat. Phys. Chem., vol. 121, pp. 75 – 80, Apr. 2016.
    DOI: 10.1016/j.radphyschem.2015.12.017
  3. C. A. Perks et al., “Introduction of the. InLight Monitoring Service,” Radiat. Prot. Dosim., vol. 125, no. 1-4, pp. 220-223, Mar. 2007.
    DOI: 10.1093/rpd/ncl126
    PMid: 17387125
  4. OSL TECHNOLOGY, Landauer, Oxford, UK.
    Retrieved from: http://www.landauer.co.uk/whole_body_osl.html
    Retrieved on: Dec. 12, 2016
  5. S. D. Miller and M. K. Murphy, “Technical performance of the Luxel Al2O3 : C optically stimulated luminescence dosemeter element at radiation oncology and nuclear accident dose levels,” Radiat. Prot. Dosim., vol. 123, no. 4, pp. 435 – 442, Mar. 2007.
    DOI: 10.1093/rpd/ncl500
    PMid: 17164274
  6. T. E. Burlin, “A general theory of cavity ionization,” J. Radiol., vol. 39, no. 466, pp. 727 – 734, Jan. 1966.
    DOI: 10.1259/0007-1285-39-466-727
    PMid: 5927191
  7. O. Nakhaei et al., “Synthesis, characterization and study of optical properties of polyvinyl alcohol/CaF2,Scientia Iranica Transactions, vol. 19, no. 6, pp. 1979 – 1983, Dec. 2012.
    DOI: 10.1016/j.scient.2012.05.008
  8. M. Luszik-Bhadra, “Prediction of neutron-induced signals in OSL materials by track structure calculation,” Radiat. Meas., vol. 46, no. 12, pp. 1694 – 1697, Dec. 2011.
    DOI: 10.1016/j.radmeas.2011.03.041
  9. S. O. Souza et al., “OSL films for in-vivo entrance dose measurements,” Radiat. Meas., press, Jul. 2017.
    DOI: 10.1016/j.radmeas.2017.07.006
  10. B. Azimi et al., “Application of the dry-spinning method to produce poly(ε-caprolactone) fibers containing bovine serum albumin laden gelatin nanoparticles,” J. Appl. Polymer Sci. vol. 133, no. 48, pp. 143 – 148, Dec. 2016.
    DOI: 10.1002/APP.44233
  11. H. Iwase et al., “Development of general-purpose particle and heavy ion transport Monte Carlo code,” J. Nucl. Sci. Technol., vol. 39, no. 11, pp. 1142 – 1151, 2002.
    DOI: 10.1080/18811248.2002.9715305
  12. K. Niita et al., “PHITS- a particle and heavy ion transport code system”, Radiat. Meas., vol. 41, pp.1080-1090, 2006
    DOI: 10.1016/j.radmeas.2006.07.013
  13. Japan Atomic Energy Agency, Tōkai, Japan, PHITS Version 2.64.
    Retrieved from: https://phits.jaea.go.jp
    Retrieved on: Dec. 12, 2016
  14. K. Niita et al., “High-energy particle transport code NMTC/JAM,” J. Nucl. Instrum. Methd. B,vol. 184, no. 3, pp. 406 – 420, Nov. 2001
  15. H. Iwase et al., “Development of heavy ion transport Monte Carlo code”, J. Nucl. Instrum. Methd. B, vol. 183, no. 3-4, pp. 374 – 382, Oct. 2001.
    DOI: 10.1007/978-3-642-18211-2_15