Neutrinos from photohadronic interactions in a GRB-afterglow

In this talk we investigate photohadronic interactions in a gamma-ray burst afterglow. Assuming that a gamma-ray burst can accelerate protons up to energies of (1020-1021) eV, we calculate the optical depth of photohadronic interactions in this energy range for protons that travel through the GRB envelope. The photonspectrum is described by synchrotron emission from a slowing down relativistic shell. We also discuss the influence of these interactions on the energy spectrum of the protons and we finally predict the neutrino flux resulting from pγ interactions for different gamma-ray bursts.