MATHEMATICAL AND EXPERIMENTAL INVESTIGATION OF THERMAL INITIATION OF EXPLOSION.
Progress rept., 1 Oct-31 Dec 66,
LEHIGH UNIV BETHLEHEM PA INST OF RESEARCH
Pagination or Media Count:
Attempts were made to reduce the leak rate and outgassing rate of the system to zero. All seals on the vacuum joints were replaced, some were redesigned and improved. A helium mass spectrometer leak detector was used to search for leaks until none could be detected. However, when the charcoal suspended from the microbalance was cooled to liquid-nitrogen temperature, the balance showed a steady-state weight increase of about two micrograms per hour. This weight gain is thought to be caused by system outgassing of heavy molecules and subsequent adsorption of this foreign material on the charcoal. The rate of weight gain can be comewhat reduced by filling the trap in front of the balance with liquid nitrogen instead of dry ice. The lower temperature of the liquid nitrogen seems more effective in trapping outgassed material coming from the furnace and preventing its reaching the charcoal. Since the steady state weight gain of the charcoal cannot be entirely eliminated, it will be necessary to make minor corrections to the raw data. Total weight increase resulting from a complete decomposition is approximately 3000 micrograms.