Energy extraction of a spinning particle via the super Penrose process from an extremal Kerr black hole

摘要

The energy extraction of the collisional Penrose process has been investigated in recent years. Previous researchers mainly concentrated on the case of nonspin massive or massless particles, and they discovered that when the collision occurs near the horizon of extremal rotating black holes, the arbitrary large efficiency can be achieved with the particle's angular momentum below the critical value as L_1 < 2. In this paper, the energy extraction of spinning massive particles is calculated via the super Penrose process. We obtain the dependence of the impact factor and the turning points on the particle's spin s. The super Penrose process can occur only when s ≤ 1 and J_1 < 2, where J1 is the spinning particle's angular momentum. It is found that the efficiency of the energy extraction is monotonously increasing with the particle's spin s increasing for s < 1, and it can become arbitrarily high when the collision occurs close to the horizon. We compare the maximum extracted energy of spinning particles with that of the nonspin case and find a significant increase of the extracted energy. When s → 1, the maximum extracted energy can be orders of magnitude larger than that of the nonspin case. For the astrophysical black holes, the large efficiency is also obtained. Naturally, when the particle's spin s ? 1, we can degenerate the result back to the nonspin case.