When the discharge takes place between the electrodes 9a and 9b inside {TAIL ~ the tube} 7, {HEAD ~ the pressure} transmitting medium 8 quickly expands due to the discharge energy 
When the discharge takes place between the electrodes 9a and 9b inside { TAIL ~ the tube } 7 , { HEAD ~ the pressure } transmitting medium 8 quickly expands due to the discharge energy
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH