Experimental Study of the Acoustic Field Generated by a 50 MeV Electron   Beam in Water
  At the MSU SINP electron accelerator, a space-time dependence of the acoustic pressure generated in water by an electron beam of 50 MeV energy was obtained. Measurements were carried out in 100 points located along the line parallel to the beam axis at the distance of 6.5 cm from the axis. At a two-dimensional diagram (distance-time) two signal tracks were observed from two sound sources: a cylindrical acoustic antenna generated by the electron beam, and an area of the beam entrance cap which divides the water medium from the air. 
V. B. Bychkov, V. S. Demidov, E. V. Demidova, A. N. Ermakov, O. D.   Ershova, B. S. Ishkhanov, V. P. Maslyany, A. Yu. Sokolo...