Dear friends
I have some problem in calculating the beam divergency. For round type crystal ( say 10 m dia.)we are entering the diameter value of the crystal in the formula but if the crystal is rectangle ( say 9 x 8 mm ) then what value we have to enter in the formula either diagonal value or the size value i.e. 8mm or 9mm ? Please guide me and what is the different between round type crystal and rectangle type crystal sound beam?