RESUMO
The sensitivity of thermoluminescent dosemeters (TLD) to 6-18 keV photons at six different effective energies was determined using an extrapolation chamber as a dosimetric standard. Photons having effective energies of 8.1, 9.2, 13.5, 13.8 and 18.0 keV were generated from an x-ray machine using appropriate kilovoltages and aluminium filters. Photons from an 55Fe source (6 keV) were also used to broaden the range of energies investigated. Observed sensitivities relative to 137Cs were found not to differ from unity with the possible exception of 6.0 keV photons. At 6.0 keV the sensitivity was found to be 0.83 +/- 0.5.
Assuntos
Compostos de Lítio , Dosimetria Termoluminescente/instrumentação , Fluoretos , Humanos , Lítio , RadiaçãoRESUMO
Surface absorbed dose rates from different hemispheric volumes of 133Xe have been measured directly with an extrapolation chamber. The results indicate that a linear relationship exists between the radius of the cloud volume and the surface absorbed dose rate for radii between 0 and 23 cm. If cloud volumes with radii larger than 23 cm are taken to be infinite with respect to the range of the charged particles emitted, the absorbed dose rate calculated based on that assumption will be within the uncertainty of any measurement of absorbed dose rate that might be made. For hemispheric volumes having radii less than or equal to 23 cm, the surface absorbed dose rate in tissue-equivalent material, in mGy h-1, is approximated (+/- 20%) by the product of [1.30 mGy h-1 cm-1 kBq-1 cm3] X [cloud radius, cm] X [cloud activity concentration, kBq cm-3].
Assuntos
Radioisótopos de Xenônio , Humanos , Modelos Estruturais , Doses de Radiação , Radiometria/instrumentaçãoRESUMO
The relative alpha-to-gamma radiation sensitivity of LiF chips (TLD-100) was determined using 241Am and 137Cs. Sensitivity is expressed in thermoluminescence per unit of absorbed dose in grays. The relative sensitivity varied from 0.13 to 0.23 with a mean of 0.18 +/- 0.03. The chips were exposed at ambient temperature and pressure.
Assuntos
Partículas alfa , Fluoretos , Compostos de Lítio , Lítio , Dosimetria Termoluminescente , Pesos e MedidasRESUMO
A survey of small air ion levels at an electronic assembly production facility was made in response to symptoms of unknown origins. Some of the symptoms are common both to psychogenic and ion imbalance illnesses. A brief review of the literature of small air ion effects on biological systems and human health is presented. Results of sampling are presented and discussed. No ion associated illness was thought to be the cause of the symptoms found.
