Comments on Neutrons as an Energy Source for the Solar Corona

Abstract

Fowler and Hashemi1 have recently suggested a coronal heating mechanism which depends on the radioactive decay in the corona of neutrons produced in the photosphere, with the subsequent energy loss of the charged decay fragments. We wish to point out that the existence of a photospheric neutron flux, of the magnitude suggested, would be detectable through observation of a flux of 2.22 MeV neutron-proton capture gamma rays, emanating from the outer ∼ 20 g cm−2 of the photosphere. We will show that the expected capture gamma ray flux based on the model1 in question is several orders of magnitude larger than observations of the continuous and sporadic emission of the 2.22 MeV gamma ray line from the Sun would indicate.