Non-existence of new quantum ergosphere effect of a vaidya-type black hole

Hawking evaporation of Dirac particles and scalar fields in a Vaidya-type b lack hole is investigated by the method of generalized tortoise coordinate transformation. It is shown that Hawking radiation of Dirac particles does not exist for P-1, Q(2) Components but for P-2, Q(1) components in any Vaid y-type black holes. Both the location and the temperature of the event hori zon change with time. The thermal radiation spectrum of Dirac particles is the same as that of Klein-Gordon particles. We demonstrate that there is no new quantum ergosphere effect in the thermal radiation of Dirac particles in any spherically symmetry black holes.