Proton Counterflow in the Pulsar Polar Cap

K. Asano (Osaka Univ.) and F. Takahara

Short abstract (200 words, maximum; text file only):
We propose a new mechanism to screen out the electric field
in the pulsar polar cap. Previous studies have shown that 
if an electron beam from the stellar surface is accelerated 
to energies high enough to create electron-positron pairs, 
the required electric field parallel to the magnetic field 
lines is too strong to screen out by the produced pairs.
We argue here that if non-relativistic protons are supplied 
>from the magnetoshere to flow towards the stellar surface,
they can provide an anode to screen out such a strong 
electric field. Injected electron-positron pairs yield an 
asymmetry of the electrostatic potential around the screening 
point. The required pair creation rate in this model is 
consistent with the conventional models.
In addition this model can bunch particles to emit coherent radiation.