A photographic plate for electron diffraction studies of high-temperature vapours

To protect the emulsion from heat radiation, photographic plates were covered with 10 μm thick aluminium foil. The foil was pasted smoothly with a pressure-sensitive adhesive on to the emulsion. A special device used for pasting the foil is described in detail. Although the sensitivity of the plate is reduced to one third of that of the bare plate for about 56 kV electrons, other properties such as density-exposure relation, reciprocity and photographic fidelity are almost the same as those of the bare plate. The covered plate can withstand radiation from a heat source of 2500°C, about 15 cm away from the plate. With this plate, sectored electron diffraction photographs of gaseous NaF, NaCl and NaBr were obtained.