The amount of beam divergence from a crystal is primarily dependent on which two factors?

The amount of beam divergence from a crystal is primarily influenced by frequency and crystal size. When discussing ultrasound technology, the frequency of the sound waves emitted by the transducer is a critical factor. Higher frequencies produce waves that are more collimated, resulting in less beam divergence, whereas lower frequencies tend to spread out more, leading to greater divergence.

Crystal size also plays an important role. A larger crystal tends to generate a more focused beam because it can produce more coherent wavefronts, resulting in less divergence. In contrast, smaller crystals typically create a wider beam, resulting in increased divergence. Together, these two factors—frequency and crystal size—determine how well the ultrasound beam can be directed toward the material being tested, which is essential for effective nondestructive testing.