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Damage Effects of Ionizing Radiation in Polymer Film Electrets

Published online by Cambridge University Press:  01 February 2011

Marco Aurélio Parada ,
Renato Amaral Minamisawa ,
Marcos Vasques Moreira ,
Adelaide de Almeida ,
Iulia Muntele  and
Daryush Ila
Marco Aurélio Parada
Affiliation:
dalmeida@ffclrp.usp.br, Universidade de São Paulo, Departamento de Física e Matemática, Avenida Bandeirantes 3900, Ribeirão Preto, São Paulo, 14040-901, Brazil
Renato Amaral Minamisawa
Affiliation:
renato@cim.aamu.edu, Universidade de São Paulo, Departamento de Física e Matemática, Avenida Bandeirantes 3900, Ribeirão Preto, São Paulo, 14040-901, Brazil
Marcos Vasques Moreira
Affiliation:
marcos-vasques@uol.com.br, Instituto de Radioterapia e Megavoltagem de Ribeirão Preto (IRMEV), Rua Sete de Setembro 1150, Ribeirão Preto, São Paulo, 14010-180, Brazil
Adelaide de Almeida
Affiliation:
dalmeida@ffclrp.usp.br, Universidade de São Paulo, Departamento de Física e Matemática, Avenida Bandeirantes 3900, Ribeirão Preto, São Paulo, 14040-901, Brazil
Iulia Muntele
Affiliation:
iulia@cim.aamu.edu, Alabama A&M University, Physics, 4900 Meridian Stre et, Normal, AL, 35762, United States
Daryush Ila
Affiliation:
ila@cim.aamu.edu, Alabama A&M University, 2Center for Irradiation of Materials, P.O. Box 1447, Normal AL, Hunstsville, Alabama, 35762-1447, United States
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Abstract

Electret sensors or dosimeters can be used to quantify the ionizing radiation dose from charged particles or waves beams (α, β, -e, p etc… γ, X), and with appropriate converters, from fast and slow neutrons. The electret state is reached, by some insulating materials (electrical conductivity lower than 10−8 (Ω m)−1), when once charged, the incorporated charge is quasi-permanent ≈ 109 s. The charge densities are read (before and after the irradiations) and the radiation dose inferred from the difference between them. PFA (Tetrafluoroethylene-per-fluoromethoxyethylene) and FEP (Tetrafluoroethylene-hexa-fluoropropylene) damage mechanisms were studied bombarding these fluoropolymers with: 1 MeV protons at constant current and fluences from 1×1011 tower 1×1016 ions/cm2, 60Co gamma and X-rays, respectively of 1.25 and 0.106 MeV for absorbed doses of 0.5, 1.0, 8,0 and 100 Gy. The emission of chemical species was monitored with a Residual Gas Analyzer (RGA), during proton bombardment and techniques of Optical Absorption Photospectrometry (OAP), Fourier Transform Infrared (FTIR) and Micro-Raman spectroscopy were used to analyze the virgin, exposed and irradiated films.

Keywords

polymerradiation effectsfilm
Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 929: Symposium II – Materials in Extreme Environments , 2006 , 0929-II04-19
Copyright
Copyright © Materials Research Society 2006

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References

1. Groh, K. K., Gaier, J. R., Hall, R. L., Espe, M. P., Cato, D. R., Sutter, J. K., Scheimank, D. A., High Perform. Polym, 12:83, 104 (2000).Google Scholar
2. Denver, J. A., Groh, K. K., Towsed, A. J., Wang, L. L., AIII paper, 0895:1 (1998).Google Scholar
3. Parada, M. A., Almeida, A. De, Nuclear Instruments and Methods In Physics Research B -Beam Interactions with Materials and Atoms., 191:1, 820 (2002).Google Scholar
4. Sessler, G. M., “Introdution and physical principles of electrets”, New York, Spring-Verlag, (1980).Google Scholar
5. Silva, N. C. da et al., “X-ray image produced on an electret film”, in: 9th International Symposium on Electrets (ISE9), (IEEE, China (1996)), pp. 1067–1072.Google Scholar
6. Rodrigues, L. N., Um novo dosímetro de eletreto para radioterapia, Master Thesis, IFSC-USP, Brazil, (1985).Google Scholar
7. Parada, M. A. et al. “Charge Density Limits in Polymer Film Electrets”, ISE12 proceedings from IEEE dielectrics and Electrical Insulation Society (2005), pp. 304–306.Google Scholar
8. Brundle, C. R., Evans, C. A. Jr., Wilson, S., “Encyclopedia of Materials Characterization: surfaces, interfaces, thin films”, Butterworth-Heinemann, Boston, 1992.Google Scholar
9. Parada, M. A. et al, “Fluoropolymers Studies for Radiation Dosimetry”, Brazilian Journal of Physics, 34 (3A), 948 (2004).Google Scholar