OSL dosimetric properties and efficiency of Brazilian natural calcium fluoride pellets

Author(s)

Malthez, Anna L. M. C. ^[1] ; Marczewska, Barbara ^[2] ; Ferreira, Felisberto ^[3] ; Umisedo, Nancy K. ^[4] ; Nowak, Tomasz ^[2] ; Bilski, Pawel ^[2] ; Yoshimura, Elisabeth M. ^[4]

Affiliation

^[1] Univ Tecnol Fed Parana, Phys Acad Dept, Av Desembargador Westphalen 637, Bloco N, BR-80010110 Curitiba, PR - Brazil

^[2] Polish Acad Sci, Inst Nucl Phys, Radzikowskiego 152, PL-31342 Krakow - Poland

^[3] Fed Inst Santa Catarina, BR-88075010 Florianopolis, SC - Brazil

^[4] Univ Sao Paulo, Inst Phys, Rua Matao 1371, BR-05508090 Sao Paulo - Brazil

• Document type: Journal article
• Source: Applied Radiation and Isotopes; v. 135, p. 166-170, MAY 2018.
• Web of Science Citations: 1

Abstract

Calcium fluoride (CaF2), in both natural and synthetic forms, has been exhaustively studied and explored as thermoluminescent (TL) detector. However its sensitivity to ambient light points to the applicability of CaF2 as OSL (Optically Stimulated Luminescence) detector, increasing the research about its luminescent properties. Although some properties to employ CaF2 detectors with OSL technique have been already demonstrated, there is a lack of some essential information as the OSL response to different types and energy of ionizing radiation. In order to extend the use of Brazilian natural CaF2 with OSL technique, we evaluated the efficiency and dosimetric properties of cold pressed CaF2:NaCl pellets. The CaF2 detectors presented good reproducibility and negligible fading of the signal over one month after irradiation. The dose response using OSL, TL and residual u, showed linear behavior for different radiation beams (protons, photons and alpha and beta particles), being equivalent to the results obtained with BeO and MTS (LiF) detectors through OSL and TL technique respectively. Moreover, differences were observed in OSL efficiency according the beam type and energy; CaF2 detectors presented a higher OSL and TL sensitivities to protons, photons and beta particles than to alpha particles. The energy response to photons obtained using OSL and residual TL intensities present an over response at lower photon energy similar to TL energy response. In addition, differences in the OSL curve shapes were observed according to radiation type and energy, pointing to the possibility of applying this material in mixed radiation fields and to estimate average LET (Linear Energy Transfer). (AU)

• FAPESP's process: 10/16437-0 - Characterization and applications of dosimetric materials using optically stimulated luminescence and complementary techniques
• Grantee: Linda Viola Ehlin Caldas
• Support type: Research Projects - Thematic Grants
• FAPESP's process: 12/13534-0 - Study of optically stimulated luminescence in BeO and CaF2
• Grantee: Felisberto Alves Ferreira Junior
• Support type: Scholarships in Brazil - Post-Doctorate