Acoustic source using a shaftless electrical hammer

摘要: A shaftless acoustic source is disclosed having a solenoid, bullet and driving electronics. The bullet, which positioned inside the solenoid's coil, can be accelerated by magnetic force generated when current pulse applied to coil. Acoustic energies are upon impact of with an object, such as borehole wall. This described Hertzian Contact Theory (also referred herein Theory) point normal time function similar half period sine function. retraction device may used retract back into solenoid after firing.