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 s _ { 1 } \approx 0.01379 \mu M and s _ { 2 } \approx - 0.2709 \mu M , we obtain the maximal efficiency is about \eta _ { max } = ( { extracted~ { } energy } ) / ( { input~ { } energy } ) \approx 15.01 , which is more than twice as large as the case of the collision of non-spinning particles ( \eta _ { max } \approx 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 \eta _ { max } \approx 26.85 when s _ { 2 } \approx - 0.2709 \mu M , which should be compared with \eta _ { max } \approx 13.93 for the nonspinning case .