| 摘要 |
<p>The method provides for discharging, from only one working chamber (2) of a source, several consecutive portions of a compressed gas into a liquid medium with, as a result, formation of a gas cavity, the chamber (2) being opened for discharge of each gas portion by means of oscillating movement of a closing cylinder (3) for a time period less than one and a half times the duration of the compression phase of the seismic signal generated by the discharge of the first portion. The pneumatic source comprises a casing (5) with an annular protrusion (6), a closing cylinder (3) movable in relation to the casing (5) and provided with an external (15) and an internal (16) annular protrusion, a stationary rod (17) forming together with the cylinder (3) a working chamber (2) and a control chamber (21). The height of the protrusion (6) equals 0.95-1.05 the height of a groove (23) of the rod (17), the ratio between the areas of the annular protrusions (15 and 16) of the cylinder (3) is 1.45-1.55, and the ratio between the height of the protrusion (6) of the casing (5) and the height of a braking stop (22) of the rod (17) is 1.45-1.55.</p> |
