Effects of ultra-strong magnetic field on electron capture rates of ⁵⁵Co and ⁵⁶Ni in the magnetar surrounding

Abstract: The electron capture rates of ⁵⁵Co and ⁵⁶Ni in the ultra-strong magnetic field at four typical temperature-density points have been calculated using the nuclear shell model and Landau energy levels quantized approximate correction. The results show that the electron capture rates of ⁵⁵Co and ⁵⁶Ni are increased greatly in the ultra-strong magnetic field, and even exceed two orders of magnitude in the range from 4.414× 10¹³G to 2.207× 10¹⁷G. The change rate of electron abundance, Ý_e, of ⁵⁵Co and ⁵⁶Ni under the condition of B=4.414× 10¹⁵G in the magnetar surrounding has been calculated and discussed, the proportions of Ý_e of ⁵⁵Co and ⁵⁶Ni in the total Ý_e have been reduced by 50 percent in all more than the condition without a magnetic field.