wherein {TAIL ~ the cylinder magnetization unit} includes a single exciting coil which is wound about {HEAD ~ the connecting portion}; and 
wherein { TAIL ~ the cylinder magnetization unit } includes a single exciting coil which is wound about { HEAD ~ the connecting portion } ; and
OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH