Pulsar wind nebulae ( PWNe ) are outstanding accelerators in Nature , in the sense that they accelerate electrons up to the radiation reaction limit .
Motivated by this observation , this paper examines the possibility that young pulsar wind nebulae can accelerate ions to ultra-high energies at the termination shock of the pulsar wind .
We consider here powerful PWNe , fed by pulsars born with \sim millisecond periods .
Assuming that such pulsars exist , at least during a few years after the birth of the neutron star , and that they inject ions into the wind , we find that protons could be accelerated up to energies of the order of the Greisen-Zatsepin-Kuzmin cut-off , for a fiducial rotation period P \sim 1 msec and a pulsar magnetic field B _ { \star } \sim 10 ^ { 13 } G , implying a fiducial wind luminosity L _ { p } \sim 10 ^ { 45 } erg/s and a spin-down time t _ { sd } \sim 3 \times 10 ^ { 7 } s. The main limiting factor is set by synchrotron losses in the nebula and by the size of the termination shock ; ions with Z \geq 1 may therefore be accelerated to even higher energies .
We derive an associated neutrino flux produced by interactions in the source region .
For a proton-dominated composition , our maximum flux lies slightly below the 5-year sensitivity of IceCube-86 and above the 3-year sensitivity of the projected Askaryan Radio Array .
It might thus become detectable in the next decade , depending on the exact level of contribution of these millisecond pulsar wind nebulae to the ultra-high energy cosmic ray flux .