  The earthward journey of ultra high energy electrons ($\sim 600$ TeV)
produced in the Pulsar atmosphere by Landau damping of magneto-centrifugally
excited Langmuir waves (drawing energy form the rotational slowdown) on primary
electrons, is charted. It is shown, that just as they escape the light cylinder
zone, the ultra-high energy particles, interacting with the medium of the Crab
nebula, rapidly loose their energy via the quantum synchrotron process,
producing highly energetic gamma rays ~ $\sim 0.6$PeV. Interacting with the
cosmic background radiation in the interstellar medium, only a tiny fraction of
these ultra high energy photons (via the $\gamma\gamma$ channel) are, then
transformed into electron-positron pairs. Detected flux of these photons
imposes an upper limit on the fraction ($4\times 10^{-7}$) of the
magnetospheric particles involved in the process of generation of ultra-high
energy photons (up to $600$ TeV).
