Two IBM-704 codes have been written which are auxiliary to the Bevatron orbit code BOC. The first, BEFCYF, interpolates among tabulated values of the median-plane magnetic flux density of the Bevatron to produce an equivalent array of values in a form appropriate to BOC. The second, DBDT, produces azimuthal derivatives of the fields produced by BEFCYF. The internal operation of BEFCYF and DBDT is described, and instructions for their execution are given.

Abstract. A series of paired explosions in a salt mine near Winnfield, Louisiana, has been conducted to test a theory by Dr. A. L. Latter concerning seismic decoupling by underground cavities. The theory predicted a decoupling of about 100. Free-field and surface measurements from an explosion in either a 6-ft- or a 15-ft-radius spherical cavity were compared with similar measurements from a completely tamped explosion. Shot sixes were from a 10 lb up to a few tons. Surface measurements were made out to 100 km and covered the frequency range from 0.05 to 100 cpa. The experiment confirmed that decoupling does occur. The actual decoupling factor as a function of frequency is presented and compared with the Latter theory.