Pulsar Radio Emission from Closed Field Lines Near Light Cylinder

摘要: The pulsar radio emission mechanism remains an enigma since over half a century. A radiation process requires not only to explain the coherency and high degree of polarization of the emission, but also nanobursts, characteristic frequency of emission, and problems like “death line”, which can#2;not be well understood in the context of long standing cap models and recent models of magnetic reconnection. This article proposes a dynamo process in pulsar magnetosphere. Through centrifu#2;gal force the last closed magnetic field lines can be amplified to a critical value of, BT ∼ 104T, which triggers magnetic reconnection responsible for the instability required in coherent curvature radiation, so that a number of problems can be interpreted. The time scale of magnetic field pile up and relaxation can be short or long for young or old pulsars respectively, which naturally account for the diverse intermittencies exhibited in pulsars and FRBs.