Energy spectrum and composition of pulsar-accelerated cosmic rays

In traversing the expanding shell of the supernova, pulsar-accelerated heavy nuclei will suffer collisions with the shell gas which lead to attenuation, and to fragmentation. Since the attainable energy decreases in time as the pulsar slows down, and the shell thins out, cosmic-ray particles of the highest energy will be most strongly affected. On the example of the Gunn-Ostriker model it is shown that 1) the attenuation reduces the maximum energy of the particles which penetrate the shell to about 0.03 of the highest energy the pulsar can produce, 2) the attenuation is stronger for heavy nuclei than for protons so that these particles remain dominant, and 3) a substantial fraction (∼2.7·10−4 in relation to protons) of L-nuclei in the cosmic radiation is formed. In addition it is shown that also the revised model provides abundant production of L-nuclei in the shell gas, and that the absorber particle radiation accelerates the shell to a modest degree only.