RESONANT INVERSE COMPTON-SCATTERING ABOVE POLAR CAPS - GAP ACCELERATION EFFICIENCY FOR YOUNG PULSARS

It is shown that for moderately hot polar caps (with effective tempera ture of similar to 10(6) K), the efficiency of polar gap acceleration is lower compared to the case in which the polar caps are relatively c ool and inverse Compton scattering plays no role in controlling the ga p. For young pulsars with superstrong magnetic fields (greater than or equal to 10(9) T) and hot polar caps (with temperature of greater tha n or equal to 5 x 10(6) K), because of the energy loss of electrons or positrons due to resonant inverse Compton scattering in the vicinity of polar caps, pair cascades occur at distances further away from the polar cap, and in this case we have a relatively high acceleration eff iciency, with ions carrying most of the particle luminosity.