A Research of Electron Capture for Nuclides in the Outer Crust of a Magnetar and

In this paper, we investigate the effects of ultra-strong magnetic fields on the electron capture (EC) rates of 53,54,55Fe, by employing the approximation of Landau level quantization, and the nuclear shell model. Our results indicate that the EC rates increase about two orders of magnitude in the ultrastrong magnetic field compared with those in the weak-field limit. The rate of change of the electron fraction, Ye for each kind of nuclide and the total Ye in the conditions of weak-field approximation and B = 4.414 × 1015 Gs have been calculated, respectively, and their differences under the two conditions exceed three orders of magnitude generally. These conclusions will play an important role in the future study of magnetar evolution.