The focusing transducer with spherical acoustic lens is studied and made. Its nominal element size is 20mm and its nominal frequency is 2.5MHz. Its focal distance in water is 25mm and its focal spot size is 2mm.
The effect of parameters of a typical confocal transducer, which is made from dividing a concave focusing transducer into two concentric parts, on the transverse and axial resolutions of a vibro-acoustography system is studied theoretically by introducing the point spread function (PSF) and defining the axial response function (ARF) based on the basic principle of vibro-acoustography.
On the theoretical basis of reciprocity calibration of focusing transducer in convergent spherical acoustic wave
During free field reciprocity calibration for a convergent spherical acoustic wave of a focusing transducer, the diffraction loss correction coefficient is a key parameter of obtaining the reciprocity coefficient.
A new type multi-elements focused transducer was presented in this paper. It is composed of six-lens style single-element transducers mounted on a concave sphere of a radius of 146 mm. The lens radius of curvature is 112mm and it is operated at 1 MHz.
A thick, focused transducer generated short (0.1μs), unipolar pressure pulses.
A through transmission ultrasonic inspection technique, which uses a flat transducer as a transmitter and a focused transducer as a receiver, is employed.
Using the extensively studied circular transducer for comparison, numerical results are shown for an unfocused transducer with uniform velocity excitation as well as for a focused transducer with Gaussian velocity excitation.
The model applies to normal-incidence, pulse-echo inspections of weakly-scattering materials using toneburst pulses from either a planar or focused transducer.
Impulse Modeling of the Rayleigh Wave Propagation Generated by a Spherical Focused Transducer
Due to its capability of producing a well localized intense heat field of predictable dimensions, the electromagnetic field focusing probe was evaluated experimentally as a surgical tool in aneurysm thrombosis.
The aneurysms were then placed under the solenoidal radiofrequency coil and the tip of the field focusing probe was inserted into them.
The UT procedures implemented for the ISI are mainly based on immersion technique using focused or focusing probe.