Caracterização e aplicação de duas câmaras de extrapolação em feixes padronizados de radiação X / Characterization and application of two extrapolation chambers in standard X radiation beams

AUTOR(ES)
FONTE

IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia

DATA DE PUBLICAÇÃO

31/03/2011

RESUMO

The extrapolation chambers are ionization chambers with variable volume, and they are mainly utilized as beta radiation detectors. In this work two extrapolation chambers were characterized, a commercial PTW extrapolation chamber and another extrapolation chamber developed at the Calibration Laboratory of IPEN, for application as reference systems in mammography, conventional diagnostic radiology and radiotherapy beams. The results obtained from the characterization tests of the chamber response: leakage current, short- and medium terms stability, determination of the saturation currents and the ion collection efficiencies, angular and energy dependence, show that these extrapolation chambers may be utilized for low-energy X radiation beam dosimetry. The transmission factors in tissue and the calibration factors were also determined for all cited radiation qualities. Finally, a procedure was established for calibration of radiation detectors in standard X radiation beams, using the extrapolation chambers.

ASSUNTO(S)

calibration factors câmara de extrapolação extrapolation chambers fator de calibração radiação x x radiation

ACESSO AO ARTIGO

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