Sampling of Dust Lofted by Air Blast Waves. Dust Sampling on Middle Gust II

摘要

Photographic observations of large scale surface and near-surface nuclear and chemical explosions have shown that in addition to the dust cloud formed by the crater ejecta, discernible amounts of surface dust are raised by the passage of the air blast wave. The dust raised by the blast wave appears to be subsequently swept back into the dust cloud (with some additional surface pickup) by the negative phase of the blast wave. It is important to know whether the dust raised by the blast wave is a significant part of the total mass of the dust cloud and whether it strongly affects the particle size distribution. The major goal of the work reported here was to measure the loading density and particle size distribution of the dust raised by the blast wave on Middle Gust II--a test using a 100-ton TNT sphere with the charge center two charge radii above the ground surface. In addition, a series of explosive tests scaled to the Middle Gust event employing up to 500 pounds of ammonium nitrate and fuel oil (ANFO) was performed to determine the optimum placement and timing of samplers for Middle Gust.