Accelerator
Intensifier, Accelerator or Booster are different names of the tool that is used in conjunction with jar to intensify or accelerate the jarring action. A good compressible fluid and an effective sealing assembly makes the intensifying action possible. It acts like a hydraulic spring that stores energy when put under strain and releases it as the strain is removed. It becomes a very useful tool in shallow intervals where the drill string length is not much.