Sound Beams Lecture

Vocabulary flashcards covering the physics of sound beams, including zones, beam diameter properties, formulas, and focusing principles.

Sound Beams

a representation of a sound beam from a single element,

CW transducer

T/F intensity is not uniform throughout

True

What does the sound beams represent

the majority of power & intensity

a small amount of the intensity travels out in some direction off the main axis

§these areas are called side lobes

What is the name of this image?

Pulse ultrasound beam

in reality, an ultrasound image is created by

many small sound beams or scan lines put together

What is Near Zone

•near zone length

distance from the element to the minimum beam diameter

What is another name of near zone

•also called near field or Freznel zone

Where does beam diameter decreases?

•decreases in the near zone

•frequency increase and increase. NZL.

What is Beam diameter

•width or diameter of the sound beam

What does beam diameter depends on?

wavelength (therefore frequency)

element diameter

distance from the transducer

At 1 NZL, beam diameter =

= ½ element diameter

at 2 NZL, beam diameter=

= element diameter

What is Focal zone?

distance from the minimum beam diameter to beyond

What is focal zone also call?

the far field or Fraunhofer zone