Dosimetria ambiental de Rn-222 e filhos : medida da eficiência absoluta do CR-39 levando-se em conta os efeitos do plate-out e fatores ambientais
PAULO, Sergio Roberto de. Dosimetria ambiental de Rn-222 e filhos: medida da eficiência absoluta do CR-39 levando-se em conta os efeitos do plate-out e fatores ambientais. 1991. f. Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Fisica Gleb Wataghin, Campinas, SP. Disponível em: <http://www.bibliotecadigital.unicamp.br/document/?code=vtls000035091>. Acesso em: 13 mar. 2017.
Paulo, Sergio Roberto de
Orientador: Julio Cesar Hadler NetoTese (doutorado) - Universidade Estadual de Campinas, Instituto de Fisica Gleb WataghinResumo: Não informadoAbstract: The subject of this work concerns with the measurement of absolute calibration factors for the use of CR-39 as an absolute detector in indoor radon and daughters monitoring. The word 'absolute' here means independence on environmental conditions like ventilation, electrostatic fields, size distribution of aerosols, etc. Up to now the usefulness of calibration factors was restricted to environmental conditions equal (or very close) to those worthing during their determinations. This fact is consequence of the difficulties related to the understanding of the plate-out properties of radon daughters activity in the air. So we devoted some time studying the plate-out effects on radon daughters monitoring performed by SSNTDs [Bi(88); Bi(89) -see chapter 5]. Our experimental results are in agreement with those of other authors about the great sensitivity of CR-39 to the plate-out effects, fact that recommended its use in this work. Being succeeded in the employment of CR-39 as an a-spectrometer we concluded that some important information¿s (like the radon daughters deposition sates on the walls of an environment) can be achieved [Had(91)]. The knowledge about the behavior of plate-out (which is precisely what obstructs the accomplishment of absolute calibration factors) made possible the determination of the ranges in zenital angle and energy where CR-39 can detect a-particle with efficiency of ~ 100%, at out conditions of track observation. In this way, we obtained calibration factors for CR-39 that are weakly dependent on environmental conditions (see chapters 9 and 10). We thin that these results can contribute to the improvement of RD detection techniquesDoutoradoFísicaDoutor em Ciencias