A reactor comprising {HEAD ~ an annular iron core} constituting {TAIL ~ a closed magnetic path} and a conductor wound on the annular core, said iron core being formed of particles of iron or an iron based magnetic material each covered with an insulative oxide film which contains 0.3 to 0.8% of oxygen by weight based on the particle 
constituting
A reactor comprising { HEAD ~ an annular iron core } constituting { TAIL ~ a closed magnetic path } and a conductor wound on the annular core , said iron core being formed of particles of iron or an iron based magnetic material each covered with an insulative oxide film which contains 0.3 to 0.8 % of oxygen by weight based on the particle
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL 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 OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH