Patent ID: 6868036

Claim:
An acoustic logging tool, comprising: an elongated transmitter module defining a transmitter module axis; and a receiver sonde including a linear array of acoustic receivers, said a receiver sonde coupled to and spaced apart from said transmitter module; wherein said transmitter module includes first and second cylindrical masses spaced apart along said axis by first and second spacers, said first cylindrical mass defining a first circular facing surface and a first cylindrical outer surface, said second cylindrical mass defining a second circular facing surface and a second cylindrical outer surface; a multi-pole acoustic source fixedly mounted between said first and second circular facing surfaces, and located on said axis between said first and second spacers; a first annular baffle assembly surrounding said outer surface having a first annular facing surface co-planar with said first circular facing surface; and a second annular baffle assembly surrounding said outer surface having a second annular facing surface co-planar with said second circular facing surface; and wherein said first and second annular facing surfaces form an acoustic waveguide.