High Energetic Background Radiation: The Main Cause for Storage Fog of Color Negative Paper

摘要

Storage fog is generally the limiting factor for shelf life of present color negative papers. Usually, cool storage is recommended for assuring best quality of paper. In a series of experiments it is shown that fogging cannot be prevented by low temperature storage, it is still observed even at a temperature of 77 K (liquid nitrogen). On the other hand, efficient shielding from high-energetic background radiation in a salt mine storage location minimizes fogging during storage to really zero. Furthermore, an exposure using ~(60)Co-γ-Radiation can simulate the fog increase during storage very well. From the results of the experiments it is concluded that high energetic (cosmic or/and terrestic) radiation is the main cause for the increase of yellow minimum density of color negative paper under normal ambient conditions.