The first fixed electrode has a central angle of {TAIL ~ 180°}, for example, and is split into a first fixed split electrode member having a central angle of {HEAD ~ 60°} and a second fixed split electrode member having a central angle of 120° 
The first fixed electrode has a central angle of { TAIL ~ 180 ° } , for example , and is split into a first fixed split electrode member having a central angle of { HEAD ~ 60 ° } and a second fixed split electrode member having a central angle of 120 °
OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH