Weighted conical transducer for generation of Bessel beam ultrasound

A conical transducer with a weighted velocity distribution is proposed as a simple and practical way of generating a quasi-non-diffracting beam. It is demonstrated theoretically that the weighted conical transducer can create a sound field almost the same as that of the Bessel beam transducer in continuous-wave excitation. In the case of short-pulse excitation, sidelobes are averaged and the pulse duration time is shorter than that of the Bessel beam transducer. It is also shown through the preliminary experiments that the weighted conical transducer has the capability of generating a narrow beam ultrasound over a long axial range