(17) 



335 



become 



where \Zq , the radius of the plate is e;'qDressed in inches and Q , the diira- 

 tion parameter of the wave, in milliseconds. In Table I p and «^n are 

 presented for several values of t-^^ & « 



TABLS I 



co/e 5 < ^fi 



0.0 1.57 1.00 



.5 2.02 .90 



1.0 2.28 .76 



2.0 2.55 .56 



3.0 2.68 .45 



5.0 2.82 .31 



If the plate is supported in one end of a long cylinder of radius 

 R with axis parallel to the direction of propagation of the incident wave, 

 an approxLiM-te treatment of the diffracted xvave can be given, since the 

 walls of the cylinder Co not diffract the primary wave, but only diffract 

 the scattered wave from the aid of the cylinder. Thus in first approxima- 

 tion, we can neglect the influence of the walls. Tliis case is of interest 

 since it corresponds roughly to the experlv.ental arrangement of the diaphragm 

 gauges employed in the Explosives Research Laboratories at Bruceton and 

 Woods Hole, 



26 



