We analyze collisional Penrose process of spinning test particles in an extreme Kerr black hole. We consider that two particles plunge into the black hole from infinity and collide near the black hole. For the collision of two massive particles, if the spins of particles are s1 ≈ 0.01379µM and s2 ≈ −0.2709µM , we obtain the maximal efficiency is about ηmax = (extracted energy)/(input energy) ≈ 15.01, which is more than twice as large as the case of the collision of non-spinning particles (ηmax ≈ 6.32). We also evaluate the collision of a massless particle without spin and a massive particle with spin (Compton scattering), in which we find the maximal efficiency is ηmax ≈ 26.85 when s2 ≈ −0.2709µM , which should be compared with ηmax ≈ 13.93 for the nonspinning case.

We analyze the collisional Penrose process between a particle on the innermost stable circular orbit (ISCO) orbit around an extreme Kerr black hole and a particle impinging from infinity. We consider both cases with non-spinning and spinning particles. We evaluate the maximal efficiency, $\eta_{\text{max}}=(\text{extracted energy})/(\text{input energy})$, for the elastic collision of two massive particles and for the photoemission process, in which the ISCO particle will escape to infinity after a collision with a massless impinging particle. For non-spinning particles, the maximum efficiency is $\eta_{\text{max}} \approx 2.562$ for the elastic collision and $\eta_{\text{max}} \approx 7$ for the photoemission process. For spinning particles we obtain the maximal efficiency $\eta_{\text{max}} \approx 8.442$ for the elastic collision and $\eta_{\text{max}} \approx 12.54$ for the photoemission process.

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